http://www.opencircuits.com/api.php?action=feedcontributions&user=RogerAF&feedformat=atomOpenCircuits - User contributions [en]2024-03-29T06:13:48ZUser contributionsMediaWiki 1.34.2http://www.opencircuits.com/index.php?title=User_talk:RogerAF&diff=15963User talk:RogerAF2008-07-16T04:01:55Z<p>RogerAF: Undo revision 15955 by 89.28.127.255 (Talk)</p>
<hr />
<div>Aloha from Honolulu,<br />
I have several areas of interest. I've been servicing recording studios here in honolulu, since the late '80s. Also concert sound, video projection, and theatrical lighting systems. I play electric rock-blues guitar and know what guitar players want from their Marshall amps. And I do recording engineering and production, so I know what recording engineers need from their monitor amps and speakers.<br />
<br />
I have several projects I'm currently working on. And several ideas I want to develop ito new projects. I was thinking about some of those when I came across this site. It seems so serendipitous, I just had to join and write something.<br />
<br />
I've spent the last week or so working on PC board layouts of several voltage regulator designs I've built and used over the years. I built a replacement for a recording console power supply regulator, that has been working now for near 10 years. I couldn't find the high current regulators that the original design used, so I used a pair of 723 ICs and external pass transistors and made my own substitute. The 723 has been bery bery goot to me! I used another pair of them to make a bench supply that adjusts from 12V to 35V plus and minus are individually adjustable and the pass devices have a 20A rating. I use this to experiment with various discrete op amp designs. A modern version of the Jensen 990 is my goal.<br />
<br />
I've also recently built my first switchmode regulator based on TIs TL494 PWM controller IC. My experience with switching regulators is limited. I never had to repair one, only replace the complete unit, so I'm having to learn about them on my own. I've collected a lot of documentation and learned about buck, boost, buck-boost, fly-back etc. But it is all "book learning" as opposed to "hands on" at this point.<br />
<br />
I thought these regulators might interest someone. I will post the schematics and artwork here eventually, but I need to find out more about how that is done. If anyone is interested, let me know.<br />
<br />
Aloha, RAF<br />
<br />
== welcome ==<br />
<br />
Aloha, RogerAF.<br />
Welcome to Open Circuits.<br />
<br />
I hope you enjoy reading OpenCircuits and sharing your knowledge with us.<br />
<br />
A few tips:<br />
* You can "sign" your contributions by typing four tildes "<nowiki>~~~~</nowiki>" at the end.<br />
* Be bold with your editing. If you add information that really belongs on some other page of this wiki (or on some other wiki entirely), or you accidentally delete some crucial stuff, it's fairly easy for anyone to fix it. Please feel free to revert or otherwise fix-up any of my edits that turn out to be erroneous and/or misguided.<br />
* We are all volunteers here.<br />
<br />
Thank you for sharing your experiences here.<br />
I also have a bunch of "book learning" about switching regulators.<br />
<br />
Have you seen [http://switcher.national.com/ National's "simple switcher"]?<br />
The web application is nice for taking specifications like "up to 3 A output current", input voltage, and output voltage, and rapidly converting it to a circuit that National guarantees will work -- rather than fiddling around with prototypes for a few days.<br />
<br />
Have you seen [http://romanblack.com/smps/a04.htm The 3-transistor Black regulator]?<br />
Or the [http://romanblack.com/smps/conv.htm +5v to +13v Converter] also by Roman Black?<br />
It makes me wonder why I used to think switchmode regulators required a complicated IC to control them.<br />
<br />
Should we start a page on switching regulators here at Open Circuits?<br />
<br />
--[[User:DavidCary|DavidCary]] 00:35, 18 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
Hi David,<br />
In response to your question re a switching regulators page. I'd vote yea and expect that a linear page should be its partner. Given that the two types are so different in approach and conception. Linear regulators are very easy for me to understand, because of my years with audio equipment--most of which used linear supplies. Switching supplies are found in audio processing units, but the repair was generally to swap in a new card rather than trouble shoot for bad components.<br />
<br />
I haven't done anything with switching regulators other than building my first with a TI TL494 PWM controller IC. I looked at Roman Black's designs (Thanks for that turn on) what elegant simplicity! I'm in awe. I am happy to contribute to a linear regulators page--I have several discrete opamp based designs for dual tracking supplies etc. I'd like to see more switching designs, to expand my own knowledge and raise my conciousness. I've peeked at National's online design software, but never took the time to try anything.<br />
<br />
I have a little project that requires +3V, +5V, and +&- 15V. I'm trying out TI's 2W DC/DC converters: DCP020515, DCP020503, and TPS5430 Step Down Converter for that application, but it's on a back burner for a while. If anyone has any experience with these I'd like to hear about it.<br />
<br />
I've just been going through the documents I've downloaded and the samples I have on hand from Texas Instruments. The more I think about it, the more a page for switching regulators makes sense. I think it should be broken into different manufacturers offerings with a cross reference at the beginning or the end--assuming there is crossing. There may be more differences than duplications--I don't know, so that is something to be researched. This should be presented to the whole community for feedback.<br />
<br />
[[User:RogerAF|RAF]] 00:28, 23 May 2007 (PDT)<br />
<br />
----<br />
<br />
I responded to your question on [[User talk:DavidCary]].<br />
I responded there, rather than here, because the last time I put half of a conversation in one place, and the other half in another place, I only confused myself :-).<br />
--[[User:DavidCary|DavidCary]] 10:22, 23 May 2007 (PDT)<br />
<br />
== editing line drawings ==<br />
<br />
For editing general line drawings,<br />
the best editor I've found is "inkscape".<br />
Download it for free ( http://inkscape.org/ ).<br />
<br />
Some people use inkscape even for sketching schematics.<br />
Other people prefer a specialized [[techniques#software_design_tools | schematic editor]].<br />
<br />
Congratulations, you've already posted more images to Open Circuits than I have :-).<br />
<br />
--[[User:DavidCary|DavidCary]] 12:51, 23 May 2007 (PDT)<br />
<br />
== switching power supply design ==<br />
<br />
[http://smps.us/ "SMPS switching power supply design: circuits, schematics, PCBs, electrical engineering reference, software, and other free online resources" ] edited by Lazar Rozenblat.<br />
<br />
== writing on wiki ==<br />
<br />
Some of my favorite pages about writing on wiki are:<br />
<br />
* [http://communitywiki.org/SentenceToPageToSectionToWiki "sentence to page to section to wiki"]<br />
* [http://communitywiki.org/BigBucketsFirstExplanation "big buckets first" explanation]<br />
* [http://communitywiki.org/PlainTalk Plain Talk]<br />
<br />
I'm dropping little snippets of information here, even though I plan to separate them out into another page someday.<br />
The "sentence to page" and the "big buckets first" essays should explain why I do this, rather than creating a fresh page now and placing 2 snippets of information into it.<br />
<br />
--[[User:68.0.120.35|68.0.120.35]] 20:54, 11 June 2007 (PDT)<br />
<br />
----<br />
<br />
'''Anonymous Edits'''<br />
<br />
To who ever edited this page earlier. You did no favors to anyone here. You did not contribute anything. You removed information that others spent time and thought composing and sharing with the community. If you did this by accident, you owe it to yourself and everyone else (not only on this wiki, but on every wiki) to learn how to use the tools properly, so you don't damage things.<br />
<br />
If you did this knowing what you do, then you are a malicious prankster and should be banned from the site.<br />
<br />
I prefer to give you the benefit of the doubt, so in the future, be more careful.<br />
<br />
[[User:RogerAF|RAF]] 06:09, 9 July 2007 (PDT)<br />
<br />
----<br />
'''More: Anonymous Edits'''<br />
<br />
Someone seems to have nothing better to do than F with stuff they shouldn't. This is the second time in as many weeks that someone stuffed a whole bunch of links at the top of this page and deleted most of the text towards the bottom. This is very poor behavior and being it's the second time, it feels malicious, no benefit of the doubt about it.<br />
<br />
--[[User:RogerAF|RAF]] 10:15, 21 December 2007 (PST)<br />
<br />
They did it again the next day ! What an Ahole!<br />
<br />
--[[User:RogerAF|RAF]] 06:52, 22 December 2007 (PST)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:RogerAF&diff=15924User talk:RogerAF2008-07-14T14:41:30Z<p>RogerAF: Undo revision 15921 by 87.234.234.66 (Talk)</p>
<hr />
<div>Aloha from Honolulu,<br />
I have several areas of interest. I've been servicing recording studios here in honolulu, since the late '80s. Also concert sound, video projection, and theatrical lighting systems. I play electric rock-blues guitar and know what guitar players want from their Marshall amps. And I do recording engineering and production, so I know what recording engineers need from their monitor amps and speakers.<br />
<br />
I have several projects I'm currently working on. And several ideas I want to develop ito new projects. I was thinking about some of those when I came across this site. It seems so serendipitous, I just had to join and write something.<br />
<br />
I've spent the last week or so working on PC board layouts of several voltage regulator designs I've built and used over the years. I built a replacement for a recording console power supply regulator, that has been working now for near 10 years. I couldn't find the high current regulators that the original design used, so I used a pair of 723 ICs and external pass transistors and made my own substitute. The 723 has been bery bery goot to me! I used another pair of them to make a bench supply that adjusts from 12V to 35V plus and minus are individually adjustable and the pass devices have a 20A rating. I use this to experiment with various discrete op amp designs. A modern version of the Jensen 990 is my goal.<br />
<br />
I've also recently built my first switchmode regulator based on TIs TL494 PWM controller IC. My experience with switching regulators is limited. I never had to repair one, only replace the complete unit, so I'm having to learn about them on my own. I've collected a lot of documentation and learned about buck, boost, buck-boost, fly-back etc. But it is all "book learning" as opposed to "hands on" at this point.<br />
<br />
I thought these regulators might interest someone. I will post the schematics and artwork here eventually, but I need to find out more about how that is done. If anyone is interested, let me know.<br />
<br />
Aloha, RAF<br />
<br />
== welcome ==<br />
<br />
Aloha, RogerAF.<br />
Welcome to Open Circuits.<br />
<br />
I hope you enjoy reading OpenCircuits and sharing your knowledge with us.<br />
<br />
A few tips:<br />
* You can "sign" your contributions by typing four tildes "<nowiki>~~~~</nowiki>" at the end.<br />
* Be bold with your editing. If you add information that really belongs on some other page of this wiki (or on some other wiki entirely), or you accidentally delete some crucial stuff, it's fairly easy for anyone to fix it. Please feel free to revert or otherwise fix-up any of my edits that turn out to be erroneous and/or misguided.<br />
* We are all volunteers here.<br />
<br />
Thank you for sharing your experiences here.<br />
I also have a bunch of "book learning" about switching regulators.<br />
<br />
Have you seen [http://switcher.national.com/ National's "simple switcher"]?<br />
The web application is nice for taking specifications like "up to 3 A output current", input voltage, and output voltage, and rapidly converting it to a circuit that National guarantees will work -- rather than fiddling around with prototypes for a few days.<br />
<br />
Have you seen [http://romanblack.com/smps/a04.htm The 3-transistor Black regulator]?<br />
Or the [http://romanblack.com/smps/conv.htm +5v to +13v Converter] also by Roman Black?<br />
It makes me wonder why I used to think switchmode regulators required a complicated IC to control them.<br />
<br />
Should we start a page on switching regulators here at Open Circuits?<br />
<br />
--[[User:DavidCary|DavidCary]] 00:35, 18 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
Hi David,<br />
In response to your question re a switching regulators page. I'd vote yea and expect that a linear page should be its partner. Given that the two types are so different in approach and conception. Linear regulators are very easy for me to understand, because of my years with audio equipment--most of which used linear supplies. Switching supplies are found in audio processing units, but the repair was generally to swap in a new card rather than trouble shoot for bad components.<br />
<br />
I haven't done anything with switching regulators other than building my first with a TI TL494 PWM controller IC. I looked at Roman Black's designs (Thanks for that turn on) what elegant simplicity! I'm in awe. I am happy to contribute to a linear regulators page--I have several discrete opamp based designs for dual tracking supplies etc. I'd like to see more switching designs, to expand my own knowledge and raise my conciousness. I've peeked at National's online design software, but never took the time to try anything.<br />
<br />
I have a little project that requires +3V, +5V, and +&- 15V. I'm trying out TI's 2W DC/DC converters: DCP020515, DCP020503, and TPS5430 Step Down Converter for that application, but it's on a back burner for a while. If anyone has any experience with these I'd like to hear about it.<br />
<br />
I've just been going through the documents I've downloaded and the samples I have on hand from Texas Instruments. The more I think about it, the more a page for switching regulators makes sense. I think it should be broken into different manufacturers offerings with a cross reference at the beginning or the end--assuming there is crossing. There may be more differences than duplications--I don't know, so that is something to be researched. This should be presented to the whole community for feedback.<br />
<br />
[[User:RogerAF|RAF]] 00:28, 23 May 2007 (PDT)<br />
<br />
----<br />
<br />
I responded to your question on [[User talk:DavidCary]].<br />
I responded there, rather than here, because the last time I put half of a conversation in one place, and the other half in another place, I only confused myself :-).<br />
--[[User:DavidCary|DavidCary]] 10:22, 23 May 2007 (PDT)<br />
<br />
== editing line drawings ==<br />
<br />
For editing general line drawings,<br />
the best editor I've found is "inkscape".<br />
Download it for free ( http://inkscape.org/ ).<br />
<br />
Some people use inkscape even for sketching schematics.<br />
Other people prefer a specialized [[techniques#software_design_tools | schematic editor]].<br />
<br />
Congratulations, you've already posted more images to Open Circuits than I have :-).<br />
<br />
--[[User:DavidCary|DavidCary]] 12:51, 23 May 2007 (PDT)<br />
<br />
== switching power supply design ==<br />
<br />
[http://smps.us/ "SMPS switching power supply design: circuits, schematics, PCBs, electrical engineering reference, software, and other free online resources" ] edited by Lazar Rozenblat.<br />
<br />
== writing on wiki ==<br />
<br />
Some of my favorite pages about writing on wiki are:<br />
<br />
* [http://communitywiki.org/SentenceToPageToSectionToWiki "sentence to page to section to wiki"]<br />
* [http://communitywiki.org/BigBucketsFirstExplanation "big buckets first" explanation]<br />
* [http://communitywiki.org/PlainTalk Plain Talk]<br />
<br />
I'm dropping little snippets of information here, even though I plan to separate them out into another page someday.<br />
The "sentence to page" and the "big buckets first" essays should explain why I do this, rather than creating a fresh page now and placing 2 snippets of information into it.<br />
<br />
--[[User:68.0.120.35|68.0.120.35]] 20:54, 11 June 2007 (PDT)<br />
<br />
----<br />
<br />
'''Anonymous Edits'''<br />
<br />
To who ever edited this page earlier. You did no favors to anyone here. You did not contribute anything. You removed information that others spent time and thought composing and sharing with the community. If you did this by accident, you owe it to yourself and everyone else (not only on this wiki, but on every wiki) to learn how to use the tools properly, so you don't damage things.<br />
<br />
If you did this knowing what you do, then you are a malicious prankster and should be banned from the site.<br />
<br />
I prefer to give you the benefit of the doubt, so in the future, be more careful.<br />
<br />
[[User:RogerAF|RAF]] 06:09, 9 July 2007 (PDT)<br />
<br />
----<br />
'''More: Anonymous Edits'''<br />
<br />
Someone seems to have nothing better to do than F with stuff they shouldn't. This is the second time in as many weeks that someone stuffed a whole bunch of links at the top of this page and deleted most of the text towards the bottom. This is very poor behavior and being it's the second time, it feels malicious, no benefit of the doubt about it.<br />
<br />
--[[User:RogerAF|RAF]] 10:15, 21 December 2007 (PST)<br />
<br />
They did it again the next day ! What an Ahole!<br />
<br />
--[[User:RogerAF|RAF]] 06:52, 22 December 2007 (PST)</div>RogerAFhttp://www.opencircuits.com/index.php?title=Category:Suppliers&diff=12183Category:Suppliers2007-12-22T15:04:21Z<p>RogerAF: Replacing page with 'See supplier.'</p>
<hr />
<div>See [[supplier]].</div>RogerAFhttp://www.opencircuits.com/index.php?title=Help:Contents&diff=12182Help:Contents2007-12-22T14:59:29Z<p>RogerAF: </p>
<hr />
<div><b>What the heck is this place?</b><br><br />
So Cina, Nate, and a guy named Aubry were all working on similar cellular projects using the [[GM862 Cellular Module]] but each project was different enough that we could not collaborate directly. However, we noticed that there was enough overlap between projects that certain things should be shared. Things like the audio biasing circuit, the power supply, and the footprint for various exotic parts. We wanted an easy way to share this information with others as well, and the concept of Open Circuits was born.<br><br><br />
<br />
We got the framework up (Cina is a pimp) in about 24hours. Even if you are completely new to Wikis, we're sure you'll find things fairly straight forward. Please use the following template (edit this change and copy/paste) into your posting as a starting point.<br><br />
<br />
----<br />
<br />
Want to know [[How to delete spam]]?<br />
<br />
----<br />
<br />
''(FIXME: move the following description to [[LT1528]])''<br />
<br />
<br />
{| align=right<br />
|-<br />
| <br />
[[Image:Main-LT1528.jpg|LT1528]]<br />
|}<br />
<b>Description:</b><br> The LT1528 is a rather expensive regulator that is known for its fast transient response and high current output. Really its known because Telit recommends it for the GM862.<br />
<br />
<b>Documents:</b><br><br />
[[Media:LT1528.pdf|LT1528 Datasheet]]<br />
<br />
<b>Footprints:</b><br><br />
Coming in a minute from SFE. This regulator comes in two packages. The 5-DD is the SMD version, while the TO-220-5 is the through hole version.<br />
<br />
<b>Manufacturer Info:</b><br><br />
Linear part # : <br><br />
LT1528CQ (5-DD SMD Package)<br> <br />
LT1528CT (TO-220-5 PTH Package)<br />
<br />
<b>Supplier Info:</b><br><br />
Digikey part # : LT1528CQ-ND<br><br />
Single Piece Price : $7.13<br />
<br />
<b>Related Items:</b><br><br />
[[GM862 Cellular Module]]<br><br />
[[GM862 SMD Connector]]<br />
<br />
<b>Original Creator:</b> --[[User:Sparkfun|Sparkfun]] 22:18, 25 January 2006 (PST)<br />
<br />
== Help ==<br />
Why can't I upload a *.cam file. It is used by Eagle for cam processors. There should be a better why to get help than posting to this page. --[[User:Linuxvolts|Linuxvolts]] 19:58, 23 May 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=OpenCircuits:Community_portal&diff=12181OpenCircuits:Community portal2007-12-22T14:54:50Z<p>RogerAF: </p>
<hr />
<div>Welcome to Open Circuits.<br />
This is a good place to talk about Open Circuits, as a whole.<br />
<br />
We have {{NUMBEROFARTICLES}} articles now. Yay!<br />
<br />
== Anti-Vandalism Bot ==<br />
It is my opinion that this should be the top goal for this site to accomplish.<br />
<br />
: ''We recently updated the $wgSpamRegex ( http://www.mediawiki.org/wiki/Manual:$wgSpamRegex ). It should block nearly all of the kinds of spam we've been seeing in the pa<br />
1000<br />
st. (Use [[Meta:Sandbox]] for testing). --[[User:DavidCary|DavidCary]] 08:46, 6 June 2007 (PDT)''<br />
::The problem is, that this is not a one time thing. It must be updated regulary, so it also works for new kinds of spam --SebDE<br />
<br />
Seeing a lot of stubborn spammers. Can we implement some kind of ip blocking mechanism?, that blocks repeated spam ip's for a week or so. Here's a list of known [[spammer ip]].<br />
:Blocking based on IPs might be usefull if it uses a maintained black or gray list, but the kind of IP blocking is used around here doesn't help much. --SebDE<br />
<br />
Disabling edits from users that aren't logged in might help a lot: http://www.mediawiki.org/wiki/Manual:Faq#How_can_I_prevent_editing_by_anonymous_users.3F --[[User:Mzandrew|Mzandrew]] 14:16, 8 September 2007 (PDT)<br />
:[[User:DavidCary|DavidCary]] wrote: "We want a system in a way that makes it very easy for anyone to help us." on his User Discussion page.<br />
:But it wouldn't hurt if the creation of new sites would be logged in users only. (Would reduce the need to delete certain articles over and over again) --SebDE<br />
<br />
Or if someone's not logged in, could we enable a captcha so that the spammers would at least have to do it manually?<br />
Here's the ReCAPTCHA extension for mediawiki sites: http://www.mediawiki.org/wiki/Extension:ReCAPTCHA<br />
There's also the ConfirmEdit extension. http://www.mediawiki.org/wiki/Extension:ConfirmEdit<br />
--[[User:Mzandrew|Mzandrew]] 13:38, 9 September 2007 (PDT)<br />
:That is way to overdesigned if you know what I mean. And just btw it is hell for accessibility. I would rather see the use other techniques like wgSpamRegex and the use of a maintained IP black list first before using such ugly things... --SebDE<br />
<br />
I have a whole bunch of PIC projects and things I think I can do to contribute to this Wiki, but the spam here is way way out of control. I'm looking at the change logs and I'<br />
1000<br />
m seeing 20 spam edits per day. I'm not so sure I want to contribute if my contributions are going to be destroyed in a matter or days. I think requiring a logon to make changes would cut out most of the spam. At this point, the problem is so bad that making things alittle harder for people to make changes is probably worth the benefits.<br />
<br />
Also, this isn't directly related to spam, but it would be nice if the site didn't put nofollow on all the URLs. I think more people would be willing to add project info pages to the wiki if they new it would make them more visable in search engines. The wiki is small enough at this point that if people start abusing this it would be easy to ban or delete their account( assuming the change is made to require a login to make edits)<br />
[[User:Mzoran|Mzoran]] 21:42, 14 October 2007 (PDT)<br />
<br />
== electrical mailing lists ==<br />
Yahoo claims they have<br />
[http://dir.groups.yahoo.com/dir/Science/Engineering/Electrical 1,831 electrical engineering mailing lists].<br />
What would be a good way of letting the people on those lists know about the Open Circuits wiki, without spamming them?<br />
--[[User:DavidCary|DavidCary]] 13:30, 31 May 2006 (PDT)<br />
<br />
* Publish cold fusion howto :-)<br />
* Send one email/week and only once per list. And be on topic, listen carefully for responses.<br />
[[User:Freqmax|Freqmax]] 16:24, 30 July 2007 (PDT)<br />
<br />
== about Open Circuits ==<br />
So, is there any connection between http://OpenCircuits.org/ , http://OpenCircuits.net/ , and this http://OpenCircuits.com/ wiki?<br />
--[[User:DavidCary|DavidCary]] 23:47, 13 June 2006 (PDT)<br />
<br />
No. There is no connection between any of http://opencircuits.com and the other websites listed.<br />
[[User:Chazegh|Chazegh]] 02:55, 18 June 2006 (PDT)<br />
== web rings ==<br />
Document an original microcontroller project and join a PIC webring, or AVR webring. 20 June 2006<br />
<br />
== audio electronics ==<br />
<br />
Is there some other wiki for people to talk about audio electronics?<br />
Or is this Open Circuits the best wiki for talking about things like<br />
''"[http://analog.com/ Analog Devices] AN-221: The Alexander current-feedback audio power amplifier"'' by Mark Alexander<br />
?<br />
<br />
I think I would prefer to offload all the audio electronics controversi<br />
1000<br />
es to some other wiki<br />
(but which one?).<br />
Still, it would be nice to have some "tips for high-power electronics" here.<br />
I imagine that tips page would list the various quirks of high-power MOSFETs, BJTs, TRIACs, and IGBTs,<br />
and (given a particular motor or speaker or other load)<br />
how to select one over the others,<br />
and various ways of working around those quirks.<br />
--[[User:65.70.89.241|65.70.89.241]] 07:17, 10 August 2006 (PDT)<br />
<br />
I just joined Open Circuits. I have been servicing and designing audio equipment for several years (Recording consoles a specialty) I hope you will have a section for audio electronics. I also work with video projection systems and theatrical lighting (stage struck at an early age) I play electric rock-blues guitar, so I also am interested in tube guitar amps (Marshall and Boogie). And there is a big difference in what a guitar player thinks an amp should do, and what a recording engineer wants an amp for. I think these are valid points for discussion.<br />
I've also got an interest in power supplies (my experience is mostly with linear, but I've started learning about switching designs). In fact that brings me to my question, I have some regulator designs based on the 723 that I'd like to share. How do I go about doing that? I built a replacement for a console /- 18V @6A supply when I couldn't find the original regulator devices. I used 723s with external series pass devices. The unit has been working for close to 10 years now, so I think the design is worth sharing. Is anyone interested? <br />
<br />
I also research discrete op amps like the Jensen 990. I've been working (on and off for years) on a clone of that using more modern, easily available parts and devices. Anyone else?<br />
Finally, in response to the first entry in this section, I too read that application note in Analog Devices Audio/Video Reference Manual. My copy is dated 1992<br />
1000<br />
. I've repaired a lot of amplifiers, but haven't built any. If anyone else is hip to this amp I'd like to hear about it. It is a very unique design. I also like the A75 amp design from Nelson Pass and Norman Thagard, and the Leach Amp by Marshall Leach. The last two are pretty normal as far as design goes, not as adventurous as the Alexander with its current-feedback approach.<br />
Aloha, RAF--[[User:66.8.194.185|66.8.194.185]] 14:04, 18 May 2007 (PDT)<br />
<br />
== automotive electronics ==<br />
<br />
Is there some other wiki for people to talk about automobile electronics?<br />
Or is this Open Circuits the best wiki for talking about things like<br />
[http://megamanual.com/ "experimental Do-It-Yourself programmable electronic fuel injection controller"]?<br />
Or should we just point people who want to talk ECUs (engine control units) to the <br />
[http://msefi.com/ MSEFI discussion forum],<br />
even though it sadly lacks a wiki?<br />
--[[User:DavidCary|DavidCary]] 22:36, 2 July 2007 (PDT)<br />
<br />
== inviting bloggers to open circuits ==<br />
<br />
=== how to connect a JTAG probe to a Nokia phone ===<br />
<br />
I'd like to invite bloggers such as GyrosGeier to edit OpenCircuits.<br />
Rather than just spamming him, I think he would be more inclined to help out<br />
if we answered one of his questions first -- such as<br />
[http://hogyros.de/?q=node/167 "If you have information on how to connect a JTAG probe to a Nokia phone, please let me know."]<br />
Maybe I should start a page on [[JTAG]]...<br />
--[[User:DavidCary|DavidCary]] 09:37, 22 September 2006 (PDT)<br />
<br />
The [http://hackedgadgets.com/ Hacked Gadgets blog also has a bunch of cool electronics].<br />
--[[User:DavidCary|DavidCary]] 11:58, 5 January 2007 (PST)<br />
<br />
== red links ==<br />
<br />
The default skin at OpenCircuits currently has "red links" = page exists, "dark red links" = page does not exist.<br />
<br />
I find that confusing. (But not as bad as the wiki that has some links black-on-white, indistinguishable from normal text).<br />
<br />
'''work-around''': Register (it's free, and you don't have to give any personal information), then choose the "preferences" link in the far upper-right corner and then pick any other skin.<br />
<br />
The other skins have coloring that you may be more used to fro<br />
1000<br />
m other wiki: "blue links" = page exists, "red links" = page does not exist.<br />
<br />
--[[User:DavidCary|DavidCary]] 08:58, 18 December 2006 (PST)<br />
<br />
<br />
*** Guys, the red color on links is AwuFul, it brings ppl headaches.<br />
That's the only reason I cant participate ***<br />
<br />
--[[User:Takeda|Takeda]] 16:38, 29 September 2007 (PDT)<br />
<br />
== inviting people from other forums to open circuits ==<br />
<br />
Lots of people talk about circuits for LED lighting at<br />
http://candlepowerforums.com/<br />
.<br />
Perhaps we can talk some of them into contributing here -- perhaps using a page or two of Open Circuits as a FAQ for LEDs and drive circuits.<br />
<br />
== tool lists ==<br />
<br />
Should we have an entire page on "tools", and mention it on the main page?<br />
That risks listing *every* tool anyone has ever heard about,<br />
like the page at<br />
http://massmind.org/techref/tools.htm<br />
.<br />
Yes, I'm responsible for uglier bits on that page;<br />
I think the wide variety of oscilloscopes are particularly confusing.<br />
How could we cut through the confusion?<br />
<br />
I see the "techniques" page already has a list of software tools.<br />
Perhaps it would be nifty to have a short list of all the tools necessary for each technique?<br />
Then a beginner would have a better idea of what tools he really needs to get (rather than looking at a huge list of every tool, and wondering for each one, ''"Am I going to regret buying it when I see it gathering dust? Or am I going to regret not buying it when I need it during a midnight debug session?"'').<br />
<br />
--[[User:DavidCary|DavidCary]] 08:37, 24 January 2007 (PST)<br />
<br />
== Requests For Help ==<br />
Thanks for your help with the camcorder mic.<br />
<br />
== sample component ==<br />
<br />
What is the purpose of the [[Sample Component]] ?<br />
--[[User:DavidCary|DavidCary]] 16:27, 7 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
== current surge and battery life ==<br />
<br />
Hi, <br />
<br />
currently my board is using a 3V battery, in every 40msec it will turn on its RF to communic<br />
1000<br />
ate with the base station. I face a problem here is that my battery life is badly affected. Turning on the RF with cause a current surge. <br />
<br />
Will this surge affect my battery life? If I use a supercapacitor does it helps?<br />
<br />
-- [[User:203.120.164.208]] 04:14, 30 April 2007<br />
<br />
<br />
== MIDI electrical interface ==<br />
<br />
In my opinion, the MIDI interface got a lot of things right that too many later interfaces still trip over.<br />
<br />
* http://www.repairfaq.org/filipg/LINK/F_MIDI.html -- ASCII schematics<br />
* http://www.engadget.com/2005/08/30/how-to-control-csound-with-a-custom-midi-controller-hardware/ -- hand-sketched schematics<br />
* http://www.midi.org/about-midi/electrical.shtml "MIDI Electrical Specification Diagram<br />
<br />
<br />
----<br />
<br />
'''SPAM DELETED!'''<br />
<br />
I deleted a whole bunch of links that had been placed at the top of this page, probably by the same AH that did it to my page. I think the best solution would be to make it so no edits are possible without being logged in. Then there will be a record of who does this kind of thing. Then they can be banned from the site. I don't think that defeats the purpose of an open wiki environment, it simply means you have to register to contribute.<br />
<br />
--[[User:RogerAF|RAF]] 10:30, 21 December 2007 (PST)<br />
<br />
At least this page is still OK. The Spam AHole hit my user talk page again today. This is very aggravating.<br />
<br />
--[[User:RogerAF|RAF]] 06:54, 22 December 2007 (PST)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:RogerAF&diff=12180User talk:RogerAF2007-12-22T14:52:19Z<p>RogerAF: </p>
<hr />
<div>Aloha from Honolulu,<br />
I have several areas of interest. I've been servicing recording studios here in honolulu, since the late '80s. Also concert sound, video projection, and theatrical lighting systems. I play electric rock-blues guitar and know what guitar players want from their Marshall amps. And I do recording engineering and production, so I know what recording engineers need from their monitor amps and speakers.<br />
<br />
I have several projects I'm currently working on. And several ideas I want to develop ito new projects. I was thinking about some of those when I came across this site. It seems so serendipitous, I just had to join and write something.<br />
<br />
I've spent the last week or so working on PC board layouts of several voltage regulator designs I've built and used over the years. I built a replacement for a recording console power supply regulator, that has been working now for near 10 years. I couldn't find the high current regulators that the original design used, so I used a pair of 723 ICs and external pass transistors and made my own substitute. The 723 has been bery bery goot to me! I used another pair of them to make a bench supply that adjusts from 12V to 35V plus and minus are individually adjustable and the pass devices have a 20A rating. I use this to experiment with various discrete op amp designs. A modern version of the Jensen 990 is my goal.<br />
<br />
I've also recently built my first switchmode regulator based on TIs TL494 PWM controller IC. My experience with switching regulators is limited. I never had to repair one, only replace the complete unit, so I'm having to learn about them on my own. I've collected a lot of documentation and learned about buck, boost, buck-boost, fly-back etc. But it is all "book learning" as opposed to "hands on" at this point.<br />
<br />
I thought these regulators might interest someone. I will post the schematics and artwork here eventually, but I need to find out more about how that is done. If anyone is interested, let me know.<br />
<br />
Aloha, RAF<br />
<br />
== welcome ==<br />
<br />
Aloha, RogerAF.<br />
Welcome to Open Circuits.<br />
<br />
I hope you enjoy reading OpenCircuits and sharing your knowledge with us.<br />
<br />
A few tips:<br />
* You can "sign" your contributions by typing four tildes "<nowiki>~~~~</nowiki>" at the end.<br />
* Be bold with your editing. If you add information that really belongs on some other page of this wiki (or on some other wiki entirely), or you accidentally delete some crucial stuff, it's fairly easy for anyone to fix it. Please feel free to revert or otherwise fix-up any of my edits that turn out to be erroneous and/or misguided.<br />
* We are all volunteers here.<br />
<br />
Thank you for sharing your experiences here.<br />
I also have a bunch of "book learning" about switching regulators.<br />
<br />
Have you seen [http://switcher.national.com/ National's "simple switcher"]?<br />
The web application is nice for taking specifications like "up to 3 A output current", input voltage, and output voltage, and rapidly converting it to a circuit that National guarantees will work -- rather than fiddling around with prototypes for a few days.<br />
<br />
Have you seen [http://romanblack.com/smps/a04.htm The 3-transistor Black regulator]?<br />
Or the [http://romanblack.com/smps/conv.htm +5v to +13v Converter] also by Roman Black?<br />
It makes me wonder why I used to think switchmode regulators required a complicated IC to control them.<br />
<br />
Should we start a page on switching regulators here at Open Circuits?<br />
<br />
--[[User:DavidCary|DavidCary]] 00:35, 18 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
Hi David,<br />
In response to your question re a switching regulators page. I'd vote yea and expect that a linear page should be its partner. Given that the two types are so different in approach and conception. Linear regulators are very easy for me to understand, because of my years with audio equipment--most of which used linear supplies. Switching supplies are found in audio processing units, but the repair was generally to swap in a new card rather than trouble shoot for bad components.<br />
<br />
I haven't done anything with switching regulators other than building my first with a TI TL494 PWM controller IC. I looked at Roman Black's designs (Thanks for that turn on) what elegant simplicity! I'm in awe. I am happy to contribute to a linear regulators page--I have several discrete opamp based designs for dual tracking supplies etc. I'd like to see more switching designs, to expand my own knowledge and raise my conciousness. I've peeked at National's online design software, but never took the time to try anything.<br />
<br />
I have a little project that requires +3V, +5V, and +&- 15V. I'm trying out TI's 2W DC/DC converters: DCP020515, DCP020503, and TPS5430 Step Down Converter for that application, but it's on a back burner for a while. If anyone has any experience with these I'd like to hear about it.<br />
<br />
I've just been going through the documents I've downloaded and the samples I have on hand from Texas Instruments. The more I think about it, the more a page for switching regulators makes sense. I think it should be broken into different manufacturers offerings with a cross reference at the beginning or the end--assuming there is crossing. There may be more differences than duplications--I don't know, so that is something to be researched. This should be presented to the whole community for feedback.<br />
<br />
[[User:RogerAF|RAF]] 00:28, 23 May 2007 (PDT)<br />
<br />
----<br />
<br />
I responded to your question on [[User talk:DavidCary]].<br />
I responded there, rather than here, because the last time I put half of a conversation in one place, and the other half in another place, I only confused myself :-).<br />
--[[User:DavidCary|DavidCary]] 10:22, 23 May 2007 (PDT)<br />
<br />
== editing line drawings ==<br />
<br />
For editing general line drawings,<br />
the best editor I've found is "inkscape".<br />
Download it for free ( http://inkscape.org/ ).<br />
<br />
Some people use inkscape even for sketching schematics.<br />
Other people prefer a specialized [[techniques#software_design_tools | schematic editor]].<br />
<br />
Congratulations, you've already posted more images to Open Circuits than I have :-).<br />
<br />
--[[User:DavidCary|DavidCary]] 12:51, 23 May 2007 (PDT)<br />
<br />
== switching power supply design ==<br />
<br />
[http://smps.us/ "SMPS switching power supply design: circuits, schematics, PCBs, electrical engineering reference, software, and other free online resources" ] edited by Lazar Rozenblat.<br />
<br />
== writing on wiki ==<br />
<br />
Some of my favorite pages about writing on wiki are:<br />
<br />
* [http://communitywiki.org/SentenceToPageToSectionToWiki "sentence to page to section to wiki"]<br />
* [http://communitywiki.org/BigBucketsFirstExplanation "big buckets first" explanation]<br />
* [http://communitywiki.org/PlainTalk Plain Talk]<br />
<br />
I'm dropping little snippets of information here, even though I plan to separate them out into another page someday.<br />
The "sentence to page" and the "big buckets first" essays should explain why I do this, rather than creating a fresh page now and placing 2 snippets of information into it.<br />
<br />
--[[User:68.0.120.35|68.0.120.35]] 20:54, 11 June 2007 (PDT)<br />
<br />
----<br />
<br />
'''Anonymous Edits'''<br />
<br />
To who ever edited this page earlier. You did no favors to anyone here. You did not contribute anything. You removed information that others spent time and thought composing and sharing with the community. If you did this by accident, you owe it to yourself and everyone else (not only on this wiki, but on every wiki) to learn how to use the tools properly, so you don't damage things.<br />
<br />
If you did this knowing what you do, then you are a malicious prankster and should be banned from the site.<br />
<br />
I prefer to give you the benefit of the doubt, so in the future, be more careful.<br />
<br />
[[User:RogerAF|RAF]] 06:09, 9 July 2007 (PDT)<br />
<br />
----<br />
'''More: Anonymous Edits'''<br />
<br />
Someone seems to have nothing better to do than F with stuff they shouldn't. This is the second time in as many weeks that someone stuffed a whole bunch of links at the top of this page and deleted most of the text towards the bottom. This is very poor behavior and being it's the second time, it feels malicious, no benefit of the doubt about it.<br />
<br />
--[[User:RogerAF|RAF]] 10:15, 21 December 2007 (PST)<br />
<br />
They did it again the next day ! What an Ahole!<br />
<br />
--[[User:RogerAF|RAF]] 06:52, 22 December 2007 (PST)</div>RogerAFhttp://www.opencircuits.com/index.php?title=OpenCircuits:Community_portal&diff=12157OpenCircuits:Community portal2007-12-21T18:30:28Z<p>RogerAF: </p>
<hr />
<div>Welcome to Open Circuits.<br />
This is a good place to talk about Open Circuits, as a whole.<br />
<br />
We have {{NUMBEROFARTICLES}} articles now. Yay!<br />
<br />
== Anti-Vandalism Bot ==<br />
It is my opinion that this should be the top goal for this site to accomplish.<br />
<br />
: ''We recently updated the $wgSpamRegex ( http://www.mediawiki.org/wiki/Manual:$wgSpamRegex ). It should block nearly all of the kinds of spam we've been seeing in the pa<br />
1000<br />
st. (Use [[Meta:Sandbox]] for testing). --[[User:DavidCary|DavidCary]] 08:46, 6 June 2007 (PDT)''<br />
::The problem is, that this is not a one time thing. It must be updated regulary, so it also works for new kinds of spam --SebDE<br />
<br />
Seeing a lot of stubborn spammers. Can we implement some kind of ip blocking mechanism?, that blocks repeated spam ip's for a week or so. Here's a list of known [[spammer ip]].<br />
:Blocking based on IPs might be usefull if it uses a maintained black or gray list, but the kind of IP blocking is used around here doesn't help much. --SebDE<br />
<br />
Disabling edits from users that aren't logged in might help a lot: http://www.mediawiki.org/wiki/Manual:Faq#How_can_I_prevent_editing_by_anonymous_users.3F --[[User:Mzandrew|Mzandrew]] 14:16, 8 September 2007 (PDT)<br />
:[[User:DavidCary|DavidCary]] wrote: "We want a system in a way that makes it very easy for anyone to help us." on his User Discussion page.<br />
:But it wouldn't hurt if the creation of new sites would be logged in users only. (Would reduce the need to delete certain articles over and over again) --SebDE<br />
<br />
Or if someone's not logged in, could we enable a captcha so that the spammers would at least have to do it manually?<br />
Here's the ReCAPTCHA extension for mediawiki sites: http://www.mediawiki.org/wiki/Extension:ReCAPTCHA<br />
There's also the ConfirmEdit extension. http://www.mediawiki.org/wiki/Extension:ConfirmEdit<br />
--[[User:Mzandrew|Mzandrew]] 13:38, 9 September 2007 (PDT)<br />
:That is way to overdesigned if you know what I mean. And just btw it is hell for accessibility. I would rather see the use other techniques like wgSpamRegex and the use of a maintained IP black list first before using such ugly things... --SebDE<br />
<br />
I have a whole bunch of PIC projects and things I think I can do to contribute to this Wiki, but the spam here is way way out of control. I'm looking at the change logs and I'<br />
1000<br />
m seeing 20 spam edits per day. I'm not so sure I want to contribute if my contributions are going to be destroyed in a matter or days. I think requiring a logon to make changes would cut out most of the spam. At this point, the problem is so bad that making things alittle harder for people to make changes is probably worth the benefits.<br />
<br />
Also, this isn't directly related to spam, but it would be nice if the site didn't put nofollow on all the URLs. I think more people would be willing to add project info pages to the wiki if they new it would make them more visable in search engines. The wiki is small enough at this point that if people start abusing this it would be easy to ban or delete their account( assuming the change is made to require a login to make edits)<br />
[[User:Mzoran|Mzoran]] 21:42, 14 October 2007 (PDT)<br />
<br />
== electrical mailing lists ==<br />
Yahoo claims they have<br />
[http://dir.groups.yahoo.com/dir/Science/Engineering/Electrical 1,831 electrical engineering mailing lists].<br />
What would be a good way of letting the people on those lists know about the Open Circuits wiki, without spamming them?<br />
--[[User:DavidCary|DavidCary]] 13:30, 31 May 2006 (PDT)<br />
<br />
* Publish cold fusion howto :-)<br />
* Send one email/week and only once per list. And be on topic, listen carefully for responses.<br />
[[User:Freqmax|Freqmax]] 16:24, 30 July 2007 (PDT)<br />
<br />
== about Open Circuits ==<br />
So, is there any connection between http://OpenCircuits.org/ , http://OpenCircuits.net/ , and this http://OpenCircuits.com/ wiki?<br />
--[[User:DavidCary|DavidCary]] 23:47, 13 June 2006 (PDT)<br />
<br />
No. There is no connection between any of http://opencircuits.com and the other websites listed.<br />
[[User:Chazegh|Chazegh]] 02:55, 18 June 2006 (PDT)<br />
== web rings ==<br />
Document an original microcontroller project and join a PIC webring, or AVR webring. 20 June 2006<br />
<br />
== audio electronics ==<br />
<br />
Is there some other wiki for people to talk about audio electronics?<br />
Or is this Open Circuits the best wiki for talking about things like<br />
''"[http://analog.com/ Analog Devices] AN-221: The Alexander current-feedback audio power amplifier"'' by Mark Alexander<br />
?<br />
<br />
I think I would prefer to offload all the audio electronics controversi<br />
1000<br />
es to some other wiki<br />
(but which one?).<br />
Still, it would be nice to have some "tips for high-power electronics" here.<br />
I imagine that tips page would list the various quirks of high-power MOSFETs, BJTs, TRIACs, and IGBTs,<br />
and (given a particular motor or speaker or other load)<br />
how to select one over the others,<br />
and various ways of working around those quirks.<br />
--[[User:65.70.89.241|65.70.89.241]] 07:17, 10 August 2006 (PDT)<br />
<br />
I just joined Open Circuits. I have been servicing and designing audio equipment for several years (Recording consoles a specialty) I hope you will have a section for audio electronics. I also work with video projection systems and theatrical lighting (stage struck at an early age) I play electric rock-blues guitar, so I also am interested in tube guitar amps (Marshall and Boogie). And there is a big difference in what a guitar player thinks an amp should do, and what a recording engineer wants an amp for. I think these are valid points for discussion.<br />
I've also got an interest in power supplies (my experience is mostly with linear, but I've started learning about switching designs). In fact that brings me to my question, I have some regulator designs based on the 723 that I'd like to share. How do I go about doing that? I built a replacement for a console /- 18V @6A supply when I couldn't find the original regulator devices. I used 723s with external series pass devices. The unit has been working for close to 10 years now, so I think the design is worth sharing. Is anyone interested? <br />
<br />
I also research discrete op amps like the Jensen 990. I've been working (on and off for years) on a clone of that using more modern, easily available parts and devices. Anyone else?<br />
Finally, in response to the first entry in this section, I too read that application note in Analog Devices Audio/Video Reference Manual. My copy is dated 1992<br />
1000<br />
. I've repaired a lot of amplifiers, but haven't built any. If anyone else is hip to this amp I'd like to hear about it. It is a very unique design. I also like the A75 amp design from Nelson Pass and Norman Thagard, and the Leach Amp by Marshall Leach. The last two are pretty normal as far as design goes, not as adventurous as the Alexander with its current-feedback approach.<br />
Aloha, RAF--[[User:66.8.194.185|66.8.194.185]] 14:04, 18 May 2007 (PDT)<br />
<br />
== automotive electronics ==<br />
<br />
Is there some other wiki for people to talk about automobile electronics?<br />
Or is this Open Circuits the best wiki for talking about things like<br />
[http://megamanual.com/ "experimental Do-It-Yourself programmable electronic fuel injection controller"]?<br />
Or should we just point people who want to talk ECUs (engine control units) to the <br />
[http://msefi.com/ MSEFI discussion forum],<br />
even though it sadly lacks a wiki?<br />
--[[User:DavidCary|DavidCary]] 22:36, 2 July 2007 (PDT)<br />
<br />
== inviting bloggers to open circuits ==<br />
<br />
=== how to connect a JTAG probe to a Nokia phone ===<br />
<br />
I'd like to invite bloggers such as GyrosGeier to edit OpenCircuits.<br />
Rather than just spamming him, I think he would be more inclined to help out<br />
if we answered one of his questions first -- such as<br />
[http://hogyros.de/?q=node/167 "If you have information on how to connect a JTAG probe to a Nokia phone, please let me know."]<br />
Maybe I should start a page on [[JTAG]]...<br />
--[[User:DavidCary|DavidCary]] 09:37, 22 September 2006 (PDT)<br />
<br />
The [http://hackedgadgets.com/ Hacked Gadgets blog also has a bunch of cool electronics].<br />
--[[User:DavidCary|DavidCary]] 11:58, 5 January 2007 (PST)<br />
<br />
== red links ==<br />
<br />
The default skin at OpenCircuits currently has "red links" = page exists, "dark red links" = page does not exist.<br />
<br />
I find that confusing. (But not as bad as the wiki that has some links black-on-white, indistinguishable from normal text).<br />
<br />
'''work-around''': Register (it's free, and you don't have to give any personal information), then choose the "preferences" link in the far upper-right corner and then pick any other skin.<br />
<br />
The other skins have coloring that you may be more used to fro<br />
1000<br />
m other wiki: "blue links" = page exists, "red links" = page does not exist.<br />
<br />
--[[User:DavidCary|DavidCary]] 08:58, 18 December 2006 (PST)<br />
<br />
<br />
*** Guys, the red color on links is AwuFul, it brings ppl headaches.<br />
That's the only reason I cant participate ***<br />
<br />
--[[User:Takeda|Takeda]] 16:38, 29 September 2007 (PDT)<br />
<br />
== inviting people from other forums to open circuits ==<br />
<br />
Lots of people talk about circuits for LED lighting at<br />
http://candlepowerforums.com/<br />
.<br />
Perhaps we can talk some of them into contributing here -- perhaps using a page or two of Open Circuits as a FAQ for LEDs and drive circuits.<br />
<br />
== tool lists ==<br />
<br />
Should we have an entire page on "tools", and mention it on the main page?<br />
That risks listing *every* tool anyone has ever heard about,<br />
like the page at<br />
http://massmind.org/techref/tools.htm<br />
.<br />
Yes, I'm responsible for uglier bits on that page;<br />
I think the wide variety of oscilloscopes are particularly confusing.<br />
How could we cut through the confusion?<br />
<br />
I see the "techniques" page already has a list of software tools.<br />
Perhaps it would be nifty to have a short list of all the tools necessary for each technique?<br />
Then a beginner would have a better idea of what tools he really needs to get (rather than looking at a huge list of every tool, and wondering for each one, ''"Am I going to regret buying it when I see it gathering dust? Or am I going to regret not buying it when I need it during a midnight debug session?"'').<br />
<br />
--[[User:DavidCary|DavidCary]] 08:37, 24 January 2007 (PST)<br />
<br />
== Requests For Help ==<br />
Thanks for your help with the camcorder mic.<br />
<br />
== sample component ==<br />
<br />
What is the purpose of the [[Sample Component]] ?<br />
--[[User:DavidCary|DavidCary]] 16:27, 7 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
== current surge and battery life ==<br />
<br />
Hi, <br />
<br />
currently my board is using a 3V battery, in every 40msec it will turn on its RF to communic<br />
1000<br />
ate with the base station. I face a problem here is that my battery life is badly affected. Turning on the RF with cause a current surge. <br />
<br />
Will this surge affect my battery life? If I use a supercapacitor does it helps?<br />
<br />
-- [[User:203.120.164.208]] 04:14, 30 April 2007<br />
<br />
<br />
== MIDI electrical interface ==<br />
<br />
In my opinion, the MIDI interface got a lot of things right that too many later interfaces still trip over.<br />
<br />
* http://www.repairfaq.org/filipg/LINK/F_MIDI.html -- ASCII schematics<br />
* http://www.engadget.com/2005/08/30/how-to-control-csound-with-a-custom-midi-controller-hardware/ -- hand-sketched schematics<br />
* http://www.midi.org/about-midi/electrical.shtml "MIDI Electrical Specification Diagram<br />
<br />
<br />
----<br />
<br />
'''SPAM DELETED!'''<br />
<br />
I deleted a whole bunch of links that had been placed at the top of this page, probably by the same AH that did it to my page. I think the best solution would be to make it so no edits are possible without being logged in. Then there will be a record of who does this kind of thing. Then they can be banned from the site. I don't think that defeats the purpose of an open wiki environment, it simply means you have to register to contribute.<br />
<br />
--[[User:RogerAF|RAF]] 10:30, 21 December 2007 (PST)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:RogerAF&diff=12156User talk:RogerAF2007-12-21T18:17:59Z<p>RogerAF: </p>
<hr />
<div>Aloha from Honolulu,<br />
I have several areas of interest. I've been servicing recording studios here in honolulu, since the late '80s. Also concert sound, video projection, and theatrical lighting systems. I play electric rock-blues guitar and know what guitar players want from their Marshall amps. And I do recording engineering and production, so I know what recording engineers need from their monitor amps and speakers.<br />
<br />
I have several projects I'm currently working on. And several ideas I want to develop ito new projects. I was thinking about some of those when I came across this site. It seems so serendipitous, I just had to join and write something.<br />
<br />
I've spent the last week or so working on PC board layouts of several voltage regulator designs I've built and used over the years. I built a replacement for a recording console power supply regulator, that has been working now for near 10 years. I couldn't find the high current regulators that the original design used, so I used a pair of 723 ICs and external pass transistors and made my own substitute. The 723 has been bery bery goot to me! I used another pair of them to make a bench supply that adjusts from 12V to 35V plus and minus are individually adjustable and the pass devices have a 20A rating. I use this to experiment with various discrete op amp designs. A modern version of the Jensen 990 is my goal.<br />
<br />
I've also recently built my first switchmode regulator based on TIs TL494 PWM controller IC. My experience with switching regulators is limited. I never had to repair one, only replace the complete unit, so I'm having to learn about them on my own. I've collected a lot of documentation and learned about buck, boost, buck-boost, fly-back etc. But it is all "book learning" as opposed to "hands on" at this point.<br />
<br />
I thought these regulators might interest someone. I will post the schematics and artwork here eventually, but I need to find out more about how that is done. If anyone is interested, let me know.<br />
<br />
Aloha, RAF<br />
<br />
== welcome ==<br />
<br />
Aloha, RogerAF.<br />
Welcome to Open Circuits.<br />
<br />
I hope you enjoy reading OpenCircuits and sharing your knowledge with us.<br />
<br />
A few tips:<br />
* You can "sign" your contributions by typing four tildes "<nowiki>~~~~</nowiki>" at the end.<br />
* Be bold with your editing. If you add information that really belongs on some other page of this wiki (or on some other wiki entirely), or you accidentally delete some crucial stuff, it's fairly easy for anyone to fix it. Please feel free to revert or otherwise fix-up any of my edits that turn out to be erroneous and/or misguided.<br />
* We are all volunteers here.<br />
<br />
Thank you for sharing your experiences here.<br />
I also have a bunch of "book learning" about switching regulators.<br />
<br />
Have you seen [http://switcher.national.com/ National's "simple switcher"]?<br />
The web application is nice for taking specifications like "up to 3 A output current", input voltage, and output voltage, and rapidly converting it to a circuit that National guarantees will work -- rather than fiddling around with prototypes for a few days.<br />
<br />
Have you seen [http://romanblack.com/smps/a04.htm The 3-transistor Black regulator]?<br />
Or the [http://romanblack.com/smps/conv.htm +5v to +13v Converter] also by Roman Black?<br />
It makes me wonder why I used to think switchmode regulators required a complicated IC to control them.<br />
<br />
Should we start a page on switching regulators here at Open Circuits?<br />
<br />
--[[User:DavidCary|DavidCary]] 00:35, 18 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
Hi David,<br />
In response to your question re a switching regulators page. I'd vote yea and expect that a linear page should be its partner. Given that the two types are so different in approach and conception. Linear regulators are very easy for me to understand, because of my years with audio equipment--most of which used linear supplies. Switching supplies are found in audio processing units, but the repair was generally to swap in a new card rather than trouble shoot for bad components.<br />
<br />
I haven't done anything with switching regulators other than building my first with a TI TL494 PWM controller IC. I looked at Roman Black's designs (Thanks for that turn on) what elegant simplicity! I'm in awe. I am happy to contribute to a linear regulators page--I have several discrete opamp based designs for dual tracking supplies etc. I'd like to see more switching designs, to expand my own knowledge and raise my conciousness. I've peeked at National's online design software, but never took the time to try anything.<br />
<br />
I have a little project that requires +3V, +5V, and +&- 15V. I'm trying out TI's 2W DC/DC converters: DCP020515, DCP020503, and TPS5430 Step Down Converter for that application, but it's on a back burner for a while. If anyone has any experience with these I'd like to hear about it.<br />
<br />
I've just been going through the documents I've downloaded and the samples I have on hand from Texas Instruments. The more I think about it, the more a page for switching regulators makes sense. I think it should be broken into different manufacturers offerings with a cross reference at the beginning or the end--assuming there is crossing. There may be more differences than duplications--I don't know, so that is something to be researched. This should be presented to the whole community for feedback.<br />
<br />
[[User:RogerAF|RAF]] 00:28, 23 May 2007 (PDT)<br />
<br />
----<br />
<br />
I responded to your question on [[User talk:DavidCary]].<br />
I responded there, rather than here, because the last time I put half of a conversation in one place, and the other half in another place, I only confused myself :-).<br />
--[[User:DavidCary|DavidCary]] 10:22, 23 May 2007 (PDT)<br />
<br />
== editing line drawings ==<br />
<br />
For editing general line drawings,<br />
the best editor I've found is "inkscape".<br />
Download it for free ( http://inkscape.org/ ).<br />
<br />
Some people use inkscape even for sketching schematics.<br />
Other people prefer a specialized [[techniques#software_design_tools | schematic editor]].<br />
<br />
Congratulations, you've already posted more images to Open Circuits than I have :-).<br />
<br />
--[[User:DavidCary|DavidCary]] 12:51, 23 May 2007 (PDT)<br />
<br />
== switching power supply design ==<br />
<br />
[http://smps.us/ "SMPS switching power supply design: circuits, schematics, PCBs, electrical engineering reference, software, and other free online resources" ] edited by Lazar Rozenblat.<br />
<br />
== writing on wiki ==<br />
<br />
Some of my favorite pages about writing on wiki are:<br />
<br />
* [http://communitywiki.org/SentenceToPageToSectionToWiki "sentence to page to section to wiki"]<br />
* [http://communitywiki.org/BigBucketsFirstExplanation "big buckets first" explanation]<br />
* [http://communitywiki.org/PlainTalk Plain Talk]<br />
<br />
I'm dropping little snippets of information here, even though I plan to separate them out into another page someday.<br />
The "sentence to page" and the "big buckets first" essays should explain why I do this, rather than creating a fresh page now and placing 2 snippets of information into it.<br />
<br />
--[[User:68.0.120.35|68.0.120.35]] 20:54, 11 June 2007 (PDT)<br />
<br />
----<br />
<br />
'''Anonymous Edits'''<br />
<br />
To who ever edited this page earlier. You did no favors to anyone here. You did not contribute anything. You removed information that others spent time and thought composing and sharing with the community. If you did this by accident, you owe it to yourself and everyone else (not only on this wiki, but on every wiki) to learn how to use the tools properly, so you don't damage things.<br />
<br />
If you did this knowing what you do, then you are a malicious prankster and should be banned from the site.<br />
<br />
I prefer to give you the benefit of the doubt, so in the future, be more careful.<br />
<br />
[[User:RogerAF|RAF]] 06:09, 9 July 2007 (PDT)<br />
<br />
----<br />
'''More: Anonymous Edits'''<br />
<br />
Someone seems to have nothing better to do than F with stuff they shouldn't. This is the second time in as many weeks that someone stuffed a whole bunch of links at the top of this page and deleted most of the text towards the bottom. This is very poor behavior and being it's the second time, it feels malicious, no benefit of the doubt about it.<br />
<br />
--[[User:RogerAF|RAF]] 10:15, 21 December 2007 (PST)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:RogerAF&diff=12155User talk:RogerAF2007-12-21T18:15:34Z<p>RogerAF: </p>
<hr />
<div>Aloha from Honolulu,<br />
I have several areas of interest. I've been servicing recording studios here in honolulu, since the late '80s. Also concert sound, video projection, and theatrical lighting systems. I play electric rock-blues guitar and know what guitar players want from their Marshall amps. And I do recording engineering and production, so I know what recording engineers need from their monitor amps and speakers.<br />
<br />
I have several projects I'm currently working on. And several ideas I want to develop ito new projects. I was thinking about some of those when I came across this site. It seems so serendipitous, I just had to join and write something.<br />
<br />
I've spent the last week or so working on PC board layouts of several voltage regulator designs I've built and used over the years. I built a replacement for a recording console power supply regulator, that has been working now for near 10 years. I couldn't find the high current regulators that the original design used, so I used a pair of 723 ICs and external pass transistors and made my own substitute. The 723 has been bery bery goot to me! I used another pair of them to make a bench supply that adjusts from 12V to 35V plus and minus are individually adjustable and the pass devices have a 20A rating. I use this to experiment with various discrete op amp designs. A modern version of the Jensen 990 is my goal.<br />
<br />
I've also recently built my first switchmode regulator based on TIs TL494 PWM controller IC. My experience with switching regulators is limited. I never had to repair one, only replace the complete unit, so I'm having to learn about them on my own. I've collected a lot of documentation and learned about buck, boost, buck-boost, fly-back etc. But it is all "book learning" as opposed to "hands on" at this point.<br />
<br />
I thought these regulators might interest someone. I will post the schematics and artwork here eventually, but I need to find out more about how that is done. If anyone is interested, let me know.<br />
<br />
Aloha, RAF<br />
<br />
== welcome ==<br />
<br />
Aloha, RogerAF.<br />
Welcome to Open Circuits.<br />
<br />
I hope you enjoy reading OpenCircuits and sharing your knowledge with us.<br />
<br />
A few tips:<br />
* You can "sign" your contributions by typing four tildes "<nowiki>~~~~</nowiki>" at the end.<br />
* Be bold with your editing. If you add information that really belongs on some other page of this wiki (or on some other wiki entirely), or you accidentally delete some crucial stuff, it's fairly easy for anyone to fix it. Please feel free to revert or otherwise fix-up any of my edits that turn out to be erroneous and/or misguided.<br />
* We are all volunteers here.<br />
<br />
Thank you for sharing your experiences here.<br />
I also have a bunch of "book learning" about switching regulators.<br />
<br />
Have you seen [http://switcher.national.com/ National's "simple switcher"]?<br />
The web application is nice for taking specifications like "up to 3 A output current", input voltage, and output voltage, and rapidly converting it to a circuit that National guarantees will work -- rather than fiddling around with prototypes for a few days.<br />
<br />
Have you seen [http://romanblack.com/smps/a04.htm The 3-transistor Black regulator]?<br />
Or the [http://romanblack.com/smps/conv.htm +5v to +13v Converter] also by Roman Black?<br />
It makes me wonder why I used to think switchmode regulators required a complicated IC to control them.<br />
<br />
Should we start a page on switching regulators here at Open Circuits?<br />
<br />
--[[User:DavidCary|DavidCary]] 00:35, 18 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
Hi David,<br />
In response to your question re a switching regulators page. I'd vote yea and expect that a linear page should be its partner. Given that the two types are so different in approach and conception. Linear regulators are very easy for me to understand, because of my years with audio equipment--most of which used linear supplies. Switching supplies are found in audio processing units, but the repair was generally to swap in a new card rather than trouble shoot for bad components.<br />
<br />
I haven't done anything with switching regulators other than building my first with a TI TL494 PWM controller IC. I looked at Roman Black's designs (Thanks for that turn on) what elegant simplicity! I'm in awe. I am happy to contribute to a linear regulators page--I have several discrete opamp based designs for dual tracking supplies etc. I'd like to see more switching designs, to expand my own knowledge and raise my conciousness. I've peeked at National's online design software, but never took the time to try anything.<br />
<br />
I have a little project that requires +3V, +5V, and +&- 15V. I'm trying out TI's 2W DC/DC converters: DCP020515, DCP020503, and TPS5430 Step Down Converter for that application, but it's on a back burner for a while. If anyone has any experience with these I'd like to hear about it.<br />
<br />
I've just been going through the documents I've downloaded and the samples I have on hand from Texas Instruments. The more I think about it, the more a page for switching regulators makes sense. I think it should be broken into different manufacturers offerings with a cross reference at the beginning or the end--assuming there is crossing. There may be more differences than duplications--I don't know, so that is something to be researched. This should be presented to the whole community for feedback.<br />
<br />
[[User:RogerAF|RAF]] 00:28, 23 May 2007 (PDT)<br />
<br />
----<br />
<br />
I responded to your question on [[User talk:DavidCary]].<br />
I responded there, rather than here, because the last time I put half of a conversation in one place, and the other half in another place, I only confused myself :-).<br />
--[[User:DavidCary|DavidCary]] 10:22, 23 May 2007 (PDT)<br />
<br />
== editing line drawings ==<br />
<br />
For editing general line drawings,<br />
the best editor I've found is "inkscape".<br />
Download it for free ( http://inkscape.org/ ).<br />
<br />
Some people use inkscape even for sketching schematics.<br />
Other people prefer a specialized [[techniques#software_design_tools | schematic editor]].<br />
<br />
Congratulations, you've already posted more images to Open Circuits than I have :-).<br />
<br />
--[[User:DavidCary|DavidCary]] 12:51, 23 May 2007 (PDT)<br />
<br />
== switching power supply design ==<br />
<br />
[http://smps.us/ "SMPS switching power supply design: circuits, schematics, PCBs, electrical engineering reference, software, and other free online resources" ] edited by Lazar Rozenblat.<br />
<br />
== writing on wiki ==<br />
<br />
Some of my favorite pages about writing on wiki are:<br />
<br />
* [http://communitywiki.org/SentenceToPageToSectionToWiki "sentence to page to section to wiki"]<br />
* [http://communitywiki.org/BigBucketsFirstExplanation "big buckets first" explanation]<br />
* [http://communitywiki.org/PlainTalk Plain Talk]<br />
<br />
I'm dropping little snippets of information here, even though I plan to separate them out into another page someday.<br />
The "sentence to page" and the "big buckets first" essays should explain why I do this, rather than creating a fresh page now and placing 2 snippets of information into it.<br />
<br />
--[[User:68.0.120.35|68.0.120.35]] 20:54, 11 June 2007 (PDT)<br />
<br />
----<br />
<br />
'''Anonymous Edits'''<br />
<br />
To who ever edited this page earlier. You did no favors to anyone here. You did not contribute anything. You removed information that others spent time and thought composing and sharing with the community. If you did this by accident, you owe it to yourself and everyone else (not only on this wiki, but on every wiki) to learn how to use the tools properly, so you don't damage things.<br />
<br />
If you did this knowing what you do, then you are a malicious prankster and should be banned from the site.<br />
<br />
I prefer to give you the benefit of the doubt, so in the future, be more careful.<br />
<br />
[[User:RogerAF|RAF]] 06:09, 9 July 2007 (PDT)<br />
<br />
----<br />
'''More: Anonymous Edits'''<br />
<br />
Someone seems to have nothing better to do than F with stuff they shouldn't. This is the second time in as many weeks that someone stuffed a whole bunch of links at the top of this page and deleted most of the text towards the bottom. This is very poor behavior and being it's the second time it feels malicious.<br />
--[[User:RogerAF|RAF]] 10:15, 21 December 2007 (PST)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:RogerAF&diff=12154User talk:RogerAF2007-12-21T18:08:13Z<p>RogerAF: </p>
<hr />
<div>Aloha from Honolulu,<br />
I have several areas of interest. I've been servicing recording studios here in honolulu, since the late '80s. Also concert sound, video projection, and theatrical lighting systems. I play electric rock-blues guitar and know what guitar players want from their Marshall amps. And I do recording engineering and production, so I know what recording engineers need from their monitor amps and speakers.<br />
<br />
I have several projects I'm currently working on. And several ideas I want to develop ito new projects. I was thinking about some of those when I came across this site. It seems so serendipitous, I just had to join and write something.<br />
<br />
I've spent the last week or so working on PC board layouts of several voltage regulator designs I've built and used over the years. I built a replacement for a recording console power supply regulator, that has been working now for near 10 years. I couldn't find the high current regulators that the original design used, so I used a pair of 723 ICs and external pass transistors and made my own substitute. The 723 has been bery bery goot to me! I used another pair of them to make a bench supply that adjusts from 12V to 35V plus and minus are individually adjustable and the pass devices have a 20A rating. I use this to experiment with various discrete op amp designs. A modern version of the Jensen 990 is my goal.<br />
<br />
I've also recently built my first switchmode regulator based on TIs TL494 PWM controller IC. My experience with switching regulators is limited. I never had to repair one, only replace the complete unit, so I'm having to learn about them on my own. I've collected a lot of documentation and learned about buck, boost, buck-boost, fly-back etc. But it is all "book learning" as opposed to "hands on" at this point.<br />
<br />
I thought these regulators might interest someone. I will post the schematics and artwork here eventually, but I need to find out more about how that is done. If anyone is interested, let me know.<br />
<br />
Aloha, RAF<br />
<br />
== welcome ==<br />
<br />
Aloha, RogerAF.<br />
Welcome to Open Circuits.<br />
<br />
I hope you enjoy reading OpenCircuits and sharing your knowledge with us.<br />
<br />
A few tips:<br />
* You can "sign" your contributions by typing four tildes "<nowiki>~~~~</nowiki>" at the end.<br />
* Be bold with your editing. If you add information that really belongs on some other page of this wiki (or on some other wiki entirely), or you accidentally delete some crucial stuff, it's fairly easy for anyone to fix it. Please feel free to revert or otherwise fix-up any of my edits that turn out to be erroneous and/or misguided.<br />
* We are all volunteers here.<br />
<br />
Thank you for sharing your experiences here.<br />
I also have a bunch of "book learning" about switching regulators.<br />
<br />
Have you seen [http://switcher.national.com/ National's "simple switcher"]?<br />
The web application is nice for taking specifications like "up to 3 A output current", input voltage, and output voltage, and rapidly converting it to a circuit that National guarantees will work -- rather than fiddling around with prototypes for a few days.<br />
<br />
Have you seen [http://romanblack.com/smps/a04.htm The 3-transistor Black regulator]?<br />
Or the [http://romanblack.com/smps/conv.htm +5v to +13v Converter] also by Roman Black?<br />
It makes me wonder why I used to think switchmode regulators required a complicated IC to control them.<br />
<br />
Should we start a page on switching regulators here at Open Circuits?<br />
<br />
--[[User:DavidCary|DavidCary]] 00:35, 18 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
Hi David,<br />
In response to your question re a switching regulators page. I'd vote yea and expect that a linear page should be its partner. Given that the two types are so different in approach and conception. Linear regulators are very easy for me to understand, because of my years with audio equipment--most of which used linear supplies. Switching supplies are found in audio processing units, but the repair was generally to swap in a new card rather than trouble shoot for bad components.<br />
<br />
I haven't done anything with switching regulators other than building my first with a TI TL494 PWM controller IC. I looked at Roman Black's designs (Thanks for that turn on) what elegant simplicity! I'm in awe. I am happy to contribute to a linear regulators page--I have several discrete opamp based designs for dual tracking supplies etc. I'd like to see more switching designs, to expand my own knowledge and raise my conciousness. I've peeked at National's online design software, but never took the time to try anything.<br />
<br />
I have a little project that requires +3V, +5V, and +&- 15V. I'm trying out TI's 2W DC/DC converters: DCP020515, DCP020503, and TPS5430 Step Down Converter for that application, but it's on a back burner for a while. If anyone has any experience with these I'd like to hear about it.<br />
<br />
I've just been going through the documents I've downloaded and the samples I have on hand from Texas Instruments. The more I think about it, the more a page for switching regulators makes sense. I think it should be broken into different manufacturers offerings with a cross reference at the beginning or the end--assuming there is crossing. There may be more differences than duplications--I don't know, so that is something to be researched. This should be presented to the whole community for feedback.<br />
<br />
[[User:RogerAF|RAF]] 00:28, 23 May 2007 (PDT)<br />
<br />
----<br />
<br />
I responded to your question on [[User talk:DavidCary]].<br />
I responded there, rather than here, because the last time I put half of a conversation in one place, and the other half in another place, I only confused myself :-).<br />
--[[User:DavidCary|DavidCary]] 10:22, 23 May 2007 (PDT)<br />
<br />
== editing line drawings ==<br />
<br />
For editing general line drawings,<br />
the best editor I've found is "inkscape".<br />
Download it for free ( http://inkscape.org/ ).<br />
<br />
Some people use inkscape even for sketching schematics.<br />
Other people prefer a specialized [[techniques#software_design_tools | schematic editor]].<br />
<br />
Congratulations, you've already posted more images to Open Circuits than I have :-).<br />
<br />
--[[User:DavidCary|DavidCary]] 12:51, 23 May 2007 (PDT)<br />
<br />
== switching power supply design ==<br />
<br />
[http://smps.us/ "SMPS switching power supply design: circuits, schematics, PCBs, electrical engineering reference, software, and other free online resources" ] edited by Lazar Rozenblat.<br />
<br />
== writing on wiki ==<br />
<br />
Some of my favorite pages about writing on wiki are:<br />
<br />
* [http://communitywiki.org/SentenceToPageToSectionToWiki "sentence to page to section to wiki"]<br />
* [http://communitywiki.org/BigBucketsFirstExplanation "big buckets first" explanation]<br />
* [http://communitywiki.org/PlainTalk Plain Talk]<br />
<br />
I'm dropping little snippets of information here, even though I plan to separate them out into another page someday.<br />
The "sentence to page" and the "big buckets first" essays should explain why I do this, rather than creating a fresh page now and placing 2 snippets of information into it.<br />
<br />
--[[User:68.0.120.35|68.0.120.35]] 20:54, 11 June 2007 (PDT)<br />
<br />
----<br />
<br />
'''Anonymous Edits'''<br />
<br />
To who ever edited this page earlier. You did no favors to anyone here. You did not contribute anything. You removed information that others spent time and thought composing and sharing with the community. If you did this by accident, you owe it to yourself and everyone else (not only on this wiki, but on every wiki) to learn how to use the tools properly, so you don't damage things.<br />
<br />
If you did this knowing what you do, then you are a malicious prankster and should be banned from the site.<br />
<br />
I prefer to give you the benefit of the doubt, so in the future, be more careful.<br />
<br />
[[User:RogerAF|RAF]] 06:09, 9 July 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:RogerAF&diff=12045User talk:RogerAF2007-12-18T16:51:37Z<p>RogerAF: </p>
<hr />
<div>Aloha from Honolulu,<br />
I have several areas of interest. I've been servicing recording studios here in honolulu, since the late '80s. Also concert sound, video projection, and theatrical lighting systems. I play electric rock-blues guitar and know what guitar players want from their Marshall amps. And I do recording engineering and production, so I know what recording engineers need from their monitor amps and speakers.<br />
<br />
I have several projects I'm currently working on. And several ideas I want to develop ito new projects. I was thinking about some of those when I came across this site. It seems so serendipitous, I just had to join and write something.<br />
<br />
I've spent the last week or so working on PC board layouts of several voltage regulator designs I've built and used over the years. I built a replacement for a recording console power supply regulator, that has been working now for near 10 years. I couldn't find the high current regulators that the original design used, so I used a pair of 723 ICs and external pass transistors and made my own substitute. The 723 has been bery bery goot to me! I used another pair of them to make a bench supply that adjusts from 12V to 35V plus and minus are individually adjustable and the pass devices have a 20A rating. I use this to experiment with various discrete op amp designs. A modern version of the Jensen 990 is my goal.<br />
<br />
I've also recently built my first switchmode regulator based on TIs TL494 PWM controller IC. My experience with switching regulators is limited. I never had to repair one, only replace the complete unit, so I'm having to learn about them on my own. I've collected a lot of documentation and learned about buck, boost, buck-boost, fly-back etc. But it is all "book learning" as opposed to "hands on" at this point.<br />
<br />
I thought these regulators might interest someone. I will post the schematics and artwork here eventually, but I need to find out more about how that is done. If anyone is interested, let me know.<br />
<br />
Aloha, RAF<br />
<br />
== welcome ==<br />
<br />
Aloha, RogerAF.<br />
Welcome to Open Circuits.<br />
<br />
I hope you enjoy reading OpenCircuits and sharing your knowledge with us.<br />
<br />
A few tips:<br />
* You can "sign" your contributions by typing four tildes "<nowiki>~~~~</nowiki>" at the end.<br />
* Be bold with your editing. If you add information that really belongs on some other page of this wiki (or on some other wiki entirely), or you accidentally delete some crucial stuff, it's fairly easy for anyone to fix it. Please feel free to revert or otherwise fix-up any of my edits that turn out to be erroneous and/or misguided.<br />
* We are all volunteers here.<br />
<br />
Thank you for sharing your experiences here.<br />
I also have a bunch of "book learning" about switching regulators.<br />
<br />
Have you seen [http://switcher.national.com/ National's "simple switcher"]?<br />
The web application is nice for taking specifications like "up to 3 A output current", input voltage, and output voltage, and rapidly converting it to a circuit that National guarantees will work -- rather than fiddling around with prototypes for a few days.<br />
<br />
Have you seen [http://romanblack.com/smps/a04.htm The 3-transistor Black regulator]?<br />
Or the [http://romanblack.com/smps/conv.htm +5v to +13v Converter] also by Roman Black?<br />
It makes me wonder why I used to think switchmode regulators required a complicated IC to control them.<br />
<br />
Should we start a page on switching regulators here at Open Circuits?<br />
<br />
--[[User:DavidCary|DavidCary]] 00:35, 18 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
Hi David,<br />
In response to your question re a switching regulators page. I'd vote yea and expect that a linear page should be its partner. Given that the two types are so different in approach and conception. Linear regulators are very easy for me to understand, because of my years with audio equipment--most of which used linear supplies. Switching supplies are found in audio processing units, but the repair was generally to swap in a new card rather than trouble shoot for bad components.<br />
<br />
I haven't done anything with switching regulators other than building my first with a TI TL494 PWM controller IC. I looked at Roman Black's designs (Thanks for that turn on) what elegant simplicity! I'm in awe. I am happy to contribute to a linear regulators page--I have several discrete opamp based designs for dual tracking supplies etc. I'd like to see more switching designs, to expand my own knowledge and raise my conciousness. I've peeked at National's online design software, but never took the time to try anything.<br />
<br />
I have a little project that requires +3V, +5V, and +&- 15V. I'm trying out TI's 2W DC/DC converters: DCP020515, DCP020503, and TPS5430 Step Down Converter for that application, but it's on a back burner for a while. If anyone has any experience with these I'd like to hear about it.<br />
<br />
I've just been going through the documents I've downloaded and the samples I have on hand from Texas Instruments. The more I think about it, the more a page for switching regulators makes sense. I think it should be broken into different manufacturers offerings with a cross reference at the beginning or the end--assuming there is crossing. There may be more differences than duplications--I don't know, so that is something to be researched. This should be presented to the whole community for feedback.<br />
<br />
[[User:RogerAF|RAF]] 00:28, 23 May 2007 (PDT)<br />
<br />
----<br />
<br />
I responded to your question on [[User talk:DavidCary]].<br />
I responded there, rather than here, because the last time I put half of a conversation in one place, and the other half in another place, I only confused myself :-).<br />
--[[User:DavidCary|DavidCary]] 10:22, 23 May 2007 (PDT)<br />
<br />
== editing line drawings ==<br />
<br />
For editing general line drawings,<br />
the best editor I've found is "inkscape".<br />
Download it for free ( http://inkscape.org/ ).<br />
<br />
Some people use inkscape even for sketching schematics.<br />
Other people prefer a specialized [[techniques#software_design_tools | schematic editor]].<br />
<br />
Congratulations, you've already posted more images to Open Circuits than I have :-).<br />
<br />
--[[User:DavidCary|DavidCary]] 12:51, 23 May 2007 (PDT)<br />
<br />
== switching power supply design ==<br />
<br />
[http://smps.us/ "SMPS switching power supply design: circuits, schematics, PCBs, electrical engineering reference, software, and other free online resources" ] edited by Lazar Rozenblat.<br />
<br />
== writing on wiki ==<br />
<br />
Some of my favorite pages about writing on wiki are:<br />
<br />
* [http://communitywiki.org/SentenceToPageToSectionToWiki "sentence to page to section to wiki"]<br />
* [http://communitywiki.org/BigBucketsFirstExplanation "big buckets first" explanation]<br />
* [http://communitywiki.org/PlainTalk Plain Talk]<br />
<br />
I'm dropping little snippets of information here, even though I plan to separate them out into another page someday.<br />
The "sentence to page" and the "big buckets first" essays should explain why I do this, rather than creating a fresh page now and placing 2 snippets of information into it.<br />
<br />
--[[User:68.0.120.35|68.0.120.35]] 20:54, 11 June 2007 (PDT)<br />
<br />
----<br />
<br />
'''Anonymous Edits'''<br />
<br />
To who ever edited this page earlier. You did no favors to anyone here. You did not contribute anything. You removed information that others spent time and thought composing and sharing with the community. If you did this by accident, you owe it to yourself and everyone else (not only on this wiki, but on every wiki) to learn how to use the tools properly, so you don't damage things.<br />
<br />
If you did this knowing what you do, then you are a malicious prankster and should be banned from the site.<br />
<br />
I prefer to give you the benefit of the doubt, so in the future, be more careful.<br />
<br />
[[User:RogerAF|RAF]] 06:09, 9 July 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:DavidCary&diff=10055User talk:DavidCary2007-10-24T14:55:32Z<p>RogerAF: </p>
<hr />
<div>== Programmable Chip EEG ==<br />
Why don't you help finish my programmable chip eeg project and then use what you learned and the results to then create your own project. Programmers like to reuse working modulas instead of reinventing the wheel.<br />
<br />
The pceeg has gone through a major revision streamlining its design and I am working on the father board a digital computing board for the project. I will be cleaning up the page. <br />
<br />
''Thank you. I hope the [[Programmable Chip EEG]] project becomes wildly successful. --[[User:DavidCary|DavidCary]] 10:01, 19 July 2007 (PDT)''<br />
<br />
==a talk through Wiki Howto==<br />
Hi DavidCary<br />
<br>Thank you very much you create this wiki to let us to share electronic projects. <br />
<br>I want to merge the "[[RS232 Dev Board]]" and "[[RS232 RS485 USB Converter Board]]", so want to discuss to the author, Tkb, of "RS232 Dev Board". However, i cannot find out the talk page like i talk to you by this way. Can you point me how to do it?<br />
<br>thanks<br />
<br>[[User:Yan|yan]]<br />
<br />
''If you have a question or comment specifically about the "RS232 Dev Board", please leave a comment on the [[RS232 Dev Board]] page or its "discussion" page.''<br />
''You can click on "[[User talk:Tkb]]" to leave a note on Tkb's user talk page.''<br />
''Since there are more people watching the "RS232 Dev Board" page than Tkb's page, you'll probably get a quicker response if you post to the "RS232 Dev Board" page than to Tkb's page.''<br />
''--[[User:DavidCary|DavidCary]] 20:00, 29 December 2006 (PST)''<br />
<br />
<br />
[[User:Chazegh|Chazegh]] created this "Open Circuits wiki".<br />
I am flattered that you think I had something to do with it.<br />
But since Chazegh seems to be too busy to spend much time here,<br />
it's up to you and I (and whoever else we can recruit) to create content here.<br />
--[[User:DavidCary|DavidCary]] 21:08, 29 December 2006 (PST)<br />
<br />
5.7.2007 Joe Silva:<br />
Hi David, great site! I've taken the liberty to remove some SPAM links from the pages. Yeah we sure do need an anti-valdalism bot. Also maybe not allow anonymous editing.<br />
<br />
----<br />
<br />
Aloha David,<br />
Roger here, I'm still puzzeled as to how to create a new article. I uploaded an image file for the 723 regulator (my article subject). This went into an "Image File page" automatically, OK. I added it to the Voltage Regulators section of Components/Integrated Circuits, OK. But I couldn't figure out how to make a document like there is for LT1528 OO. I put the info I have into the discussion page for the image, but that is only a temporary solution.<br />
<br />
How does one create a new article page that isn't a "talk" page for something else? Beside the info on the IC, I have a couple of documents that are in-depth on using the device. These should be near each other as well as near the info document above. How would I go about setting up a "723" sub-chapter of "Integrated Circuits"? I guess that's as clear as I can make the question.<br />
<br />
I would also like to suggest a modification to the linkage. I'm reading the synopsis on the LT1528, I want to find oout more, so I click on the image, but instead of taking me to an in-depth article, it takes me to the image file page. There I have to look at the Links to find the article (which is only identified as LT1528). I'd like to be taken to the article instead of the image. Take me to the image only if there is no article. Of course this may be more difficult to make happen--I don't know how the site is structured. My web programming is very basic. Still, I think this makes sense from a user's POV.<br />
<br />
Thanks in Advance,<br />
[[User:RogerAF|RAF]] 17:26, 22 May 2007 (PDT)<br />
<br />
Aloha, Roger.<br />
You're doing great.<br />
<br />
I agree that it would be nice if clicking on the picture of the LT1528 took you directly to the article about the LT1528.<br />
I don't know how to fix it.<br />
<br />
Do you see the "Help" link in the navigation bar on the left side of every page?<br />
I think the page it brings up needs a few more tips.<br />
But I want to keep it short and simple.<br />
If I explained every detail, it would become a bloated 100-page document that nobody would read.<br />
<br />
There are already far too many bloated 100-page documents about electronics.<br />
<br />
I hope that you, dear reader, and other volunteers will make Open Circuits into a place where people can learn to do amazing things.<br />
A place that avoids forcing people to learn 100 irrelevant details before learning the one thing they need to know before they get back to building their robot (or whatever).<br />
A place that never makes people throw away good ideas, because we never confuse people into believing that it would be far more complicated and expensive to build than it really is.<br />
<br />
p.s.:<br />
Picking the name of a page is a bit of an art.<br />
Since we want to refer to a page a lot, that's easier when the name is very short.<br />
People new to wiki always pick names that are too long, or have too many capital letters.<br />
Fortunately, it's very simple to rename pages.<br />
You rename pages by clicking on the incorrectly-named "Move this page" button.<br />
(I don't know how to fix that, either).<br />
--[[User:DavidCary|DavidCary]] 10:15, 23 May 2007 (PDT)<br />
<br />
=== making links ===<br />
<br />
Speaking of linkage, making links is one of the most important parts of this wiki.<br />
<br />
Whenever you find one article mentioning some other article, you can click on that word to get more detail.<br />
<br />
If that word is not already clickable (underlined and colored), please make it clickable.<br />
To make a word clickable, hit the "edit" button at the top of the page.<br />
Then add double brackets <nowiki>"[["</nowiki> and <nowiki>"]]"</nowiki> around that word.<br />
(Some people recommend only making the first mention of that word clickable).<br />
<br />
The cheatsheet ( http://en.wikipedia.org/wiki/Wikipedia:Cheatsheet ) calls this an "internal link".<br />
<br />
Here's the trick: you can add those brackets to any word, making it into a link.<br />
Some of those links will go to pages that don't exist yet.<br />
<br />
What happens when you click on one of those links to a page that doesn't exist yet?<br />
<br />
I'm not going to tell you what happens.<br />
Go find out for yourself.<br />
You can practice in the [[meta:Sandbox]].<br />
<br />
--[[User:DavidCary|DavidCary]] 10:15, 23 May 2007 (PDT)<br />
<br />
----<br />
Aloha David,<br />
Roger again; I want to thank you for the info and hints. I'm catching on. I got my component description linked to the caption under the image on the Components/Voltage Regulators page. And I created a "New Article" which I then "moved" to the title of my article. And my article has a link to the description and that has a link to the article, so I'm getting the hang of it. I have several schematics and PC artwork images to upload and link to my article, plus a second article I want to publish (I didn't write it, but I've been unable to find it on the internet--I have a xeroxed copy from 1986 or so and that is the only existing one as far as I know). That article also has several images that go along with it. I wondered about the feasability of uploading a .pdf file (I made one of it) to this site. Would that work? Should I even try? I don't want to screw anything up, but wouldn't that be a lovely thing if we could upload .pdf files? Just a thought.<br />
<br />
Again, Thanks very much, I've made some progress.<br />
<br />
[[User:RogerAF|RAF]] 19:48, 23 May 2007 (PDT)<br />
<br />
Aloha, Roger.<br />
You are welcome.<br />
Have you tried creating a link to an article that doesn't exist yet, just to see what happens when you click on that link? For example, the [[switching regulator]] page that I'm going to start in a few days.<br />
<br />
I don't know about this article that you didn't write.<br />
If the original author wants people to post it widely, and doesn't mind us editing it, then great, let's post it (and give correct attribution).<br />
But some writers go a little crazy when they see that someone random stranger has copied their stuff and posted it to the internet.<br />
(That's why there's that "DO NOT SUBMIT COPYRIGHTED WORK WITHOUT PERMISSION!" note at the bottom of each Edit page).<br />
<br />
I wouldn't mind you posting a .pdf file (that you wrote) temporarily.<br />
It's better than nothing.<br />
But I would expect someone to eventually convert it to text-and-images.<br />
That makes it much easier for the next person to improve the it.<br />
<br />
Thank you again for adding useful information to Open Circuits.<br />
I hope you won't mind people "improving" the things you post here.<br />
<br />
--[[User:DavidCary|DavidCary]] 21:26, 23 May 2007 (PDT)<br />
<br />
Aloha David,<br />
Sorry for the delay, I had a loonng job and then our cable modem failed. At least they swapped us a new one free (hooray RoadRunner). But I want to explain the article: "The Many-Talented 723" by Glenn Prescott. I came across this as a xerox copy sometime around 1985. It was evidently published in a magazine for radio enthusiasts--there are some ads on the last page for radio gear. But the name of the magazine isn't on any of the pages. I Googled for the article and got no returns. I think it is a very good article as far as describing the IC and how to use it. It helped me when I was a beginner, so I want to share it. However, I don't want anyone to get into trouble over it. I just did another search on Google and all the returns refer to my mention of it here on Open Circuits. Like I said, this is a copy that I have, no clue as to the magazine that published it, no copyright date, no nothin'. But I will leave it to your judgement if it is a risk. I still have my own article to get uploaded along with images. I will concentrate on getting mine done before doing anything with the copied article.<br />
<br />
[[User:RogerAF|RAF]] 20:27, 26 May 2007 (PDT)<br />
<br />
Unless the author has given permission to publish it, I think a better idea would be to write your own article, citing the one you're talking about further details. Ideas are not copyright, but the expression of them (i.e. the text of the article) is, or so I understand. [[User:Autarch|Autarch]] 10:22, 13 June 2007 (PDT)<br />
<br />
== spammers ==<br />
<br />
I think I know how to dramatically reduce the amount of linkspam on the website i think if the administrators on this site protect pages that are frequently spammed such as [[Open Circuits talk:Community Portal]] that will reduce the amount of spam on this site because the spammers will not be able to edit those pages.--[[User:71.234.233.163|71.234.233.163]] 08:21, 2 June 2007 (PDT)<br />
<br />
:I just signed up a few minutes ago and noticed that there seems to be a lot of linkspam being placed by unregistered users. I don't want to exclude folk, but would only allowing registered users to edit cut down some of the spam? [[User:Autarch|Autarch]] 09:53, 13 June 2007 (PDT)<br />
<br />
::You are right.<br />
::Certainly that is one way to cut down on spam, and perhaps I will be forced to do that soon.<br />
<br />
Another way, as you can see from [[Special:Ipblocklist]], I've been banning a bunch of anonymous spammers.<br />
<br />
:But is there another, better way to reduce spam?<br />
<br />
:I want to avoid a problem I am starting to notice.<br />
:Sometimes I see a tiny little typo or technopropisms or some other tiny little thing that I could easily fix<br />
:( http://communitywiki.org/WhyWikiWorks ).<br />
:But someone has built a huge barrier that prevents me from helping.<br />
:We want a system in a way that makes it very easy for anyone to help us.<br />
:Certainly too much spam is leaking through just now, but I don't want to go to the opposite extreme and make people go through a big complicated procedure in order to improve a schematic or fix a typo.<br />
:--[[User:DavidCary|DavidCary]] 21:39, 21 June 2007 (PDT)<br />
<br />
::That's a very noble way of thinking. I also like to be able to edit anonymously... There are enough sites you have to register for already. --SebDE<br />
<br />
::I know how to greatly reducethe amount of spam without stopping anomyomus ips from editing you can install a spam filter [http://wiki.cotch.net/index.php/Spam_filter like the one at my website EvoWiki] we usually dont get much spam at EvoWiki because we have a spam filter.--[[User:71.234.233.163|71.234.233.163]] 15:01, 22 June 2007 (PDT)<br />
<br />
:::Indeed, a black list based on words is the way to go here. BTW this seems to be an extension you need to install from [http://meta.wikimedia.org/wiki/SpamBlacklist_extension there]<br />
:::And an easy way to monitor for spam can help, too. The spam cops around here might want to check out those [http://en.wikipedia.org/wiki/Wikipedia:Tools/Editing_tools wiki editing tools] ;) --SebDE<br />
::::Bummer, they recently moved the BalckList Extension to the Extension namespace http://www.mediawiki.org/wiki/Extension:SpamBlacklist<br />
::::Anyways, if you've problem with installing that or in doubt of maintaining - I run several mediawikis for private use and am quite advanced with regexes, although only very simple ones are needed for the BlackList.<br />
::::--SebDE<br />
:::::Well I just digged through the code of the Extension and spotted a spam filter option that is already there in the MediaWiki software. It would involve edititing the configuration for any new spam pattern, tough. --SebDE<br />
<br />
'''Anonymous Edits?'''<br />
Aloha from Honolulu David,<br />
I just got an email saying my page had been edited by an anonymous user. I don't know who this is, there is nothing his/her page. I would not be complainig if the edits had improved things, but all they did was delete information. Perhaps it is their sense of humor.<br />
I am glad there is the record of changes made, so I can try to recover what was removed. Just to let you know that apparently spammers are not all you have to worry about.<br />
<br />
Roger<br />
[[User:RogerAF|RAF]] 05:58, 9 July 2007 (PDT)<br />
<br />
P. S.<br />
<br />
I just finished replacing what had been rmoved. Again, I'm grateful for the changes records. I also left a note to whoever did it. I think possibly it was unintentional. I hope that's the case.<br />
<br />
It occurred to me that perhaps editing should not be allowed by anonymous users. Perhaps there could be a special page that allowed anonimity, but require identification from anyone who wants to perform edits on pages that others have posted.<br />
<br />
I don't know how you'd acomplish it. I'm just a bit po'd that this can happen. He could have easily deleted the whole page. I'm glad it was easy to repair, but I will be moving come the middle of August and I may not have email for a week or two, possibly longer. So if something like this happened then, I would not know for some time. Then it would be a problem. Forgive my rant, but see my point? I'll leave it at that and check back later.<br />
<br />
[[User:RogerAF|RAF]] 06:23, 9 July 2007 (PDT)<br />
<br />
I'm sorry that your page was damaged.<br />
Certainly, blocking "ip users" would have stopped this particular problem.<br />
But is there a better solution?<br />
One that doesn't force people to go through a "identification process" before fixing a little typo?<br />
--[[User:DavidCary|DavidCary]] 14:45, 9 July 2007 (PDT)<br />
:Yes, there is, I already posted this. http://www.mediawiki.org/wiki/Extension:SpamBlacklist<br />
:4 simple steps:<br />
:* Create an article for spam phrases -- I'll pop up more often (even create an account) and help maintaining this list ;)<br />
:* Protect this Article against anonymous edits<br />
:* Install the Extension<br />
:* Configure the extension to use the just created Article (in this example [[spam blacklist]]):<br />
<pre><br />
require_once( "$IP/extensions/SpamBlacklist/SpamBlacklist.php" );<br />
$wgSpamBlacklistFiles = array(<br />
"DB: $wgDBname spam_blacklist",<br />
);<br />
</pre><br />
:--SebDE<br />
<br />
== OpenCircuits Guideline ==<br />
<br />
<br />
Here is a rewritten guidline as per your request. It may need some polishing:<br />
<br />
''... moved to [[We love volunteers]] ...''<br />
<br />
[[User_talk:Freqmax]]<br />
<br />
Start the page [[Guideline]] ..?<br />
<br />
''I think that's great. We might want a "guideline" page someday, but for now I'm going to stick it over into "[[We love volunteers]]".'' --[[User:DavidCary|DavidCary]] 00:44, 3 August 2007 (PDT)<br />
<br />
== Delete object ==<br />
<br />
[http://www.opencircuits.com/index.php?title=Image:Geda_pcb_print_layout.png&action=delete&oldimage=20070731124511%21Geda_pcb_print_layout.png&wpEditToken=f5d80d0b9e925f6a32d06cabf08f986b%5C Can you delete this?] [[User:Freqmax|Freqmax]] 05:50, 31 July 2007 (PDT)<br />
<br />
== Spam ==<br />
<br />
Do you have adminstrative priviligies?, anyway I have summerized the [[Spammer ip|spammers ip here]] and noticed, that the same networks. And esp same edit comment and content tend to stay the same. It would benefitial to be able to block these rougue networks and aswell block submission of any page that contains these phrases in their edit summary. Or spammer links.<br />
<br />
''I'm a "sysop" now.''<br />
''I've banned a bunch of individual IPs,''<br />
''but I hope that fine-tuning the "$wgSpamRegex" will not only save me time, but also avoid annoying people sincerely trying to help.''<br />
''(Please use the [[Sandbox]] to post words/phrases/URLs that ought to go into the "$wgSpamRegex").''<br />
<br />
:Amen to that.<br />
<br />
''And I see that someone recently installed the''<br />
''[[Special:Contributions/Spam cleanup script]]''<br />
''on 30 July 2007.''<br />
''I'm guessing that's the same''<br />
''[http://www.wikia.com/wiki/Spam_cleanup_script script that Tim Starling wrote].''<br />
''--[[User:DavidCary|DavidCary]] 01:23, 3 August 2007 (PDT)''<br />
<br />
:Well, as with the banning of IPs, the spam problem could be adressed earlier, so it not even appears in the history. $wgSpamRegex is the better choice in my opinion. I'll come up with a regex somewhen this weekend or so ;)<br />
<br />
I suggest that ip blocks (see [[Spammer ip]]) like 217.141.249.0/24 (Interbusiness Italy) are used for any ip that spam on sight. And that users from such address blocks are blocked from doing any edits. But may create a user account and then edit. This is due that most spam is made from accountless ip addresses. This will allow everybody to still edit while preventing most spam. Maybe it could be made possible for people without sysop access to add ip-ban?<br />
[[User:Freqmax|Freqmax]] 11:55, 12 August 2007 (PDT)<br />
<br />
:Did it came to your mid that this might not be the ultimative solution to a spam problem? Did it ever occur to you that the same kind of spam comes from (regional) totally independent IP ranges? Have you noticed that spam can origin virtually everywhere? Do you want to block every IP in the internet? :)<br />
<br />
::I have noticed that certain countries like China, Russia, Italy etc.. tend to be overrepresented. And ofcourse one should block ranges not individual IPs. Other than that pattern matching (regex) is proberbly the way. Most spam seems to contain full qualified links to domains that tend to reoccour. My hope is we can improve such that we don't need spend so much time on cleaning up.<br />
<br />
: Wow, this spam is getting quite nasty. I'm all for openess and such, but perhaps it's time to change the settings so only verified users can make edits. I'd rather spend my time designing a nifty new circuit than removing spam. Spam me if I've suggested the unthinkable.--[[User:Yzf600|Yzf600]] 17:25, 28 August 2007 (PDT)<br />
::Indeed, if you want to enable anonymous editing, you have to use advanced spam fighting methods. This site is of no use in the current state. --SebDE<br />
<br />
::: Yes, this spam is nasty. The $wgSpamRegex seems to be broken today -- sorry. I hope this gets fixed soon. --[[User:DavidCary|DavidCary]] 23:31, 30 August 2007 (PDT)<br />
<br />
I have written a quick guide on how to remove spam [[How to delete spam]] to help people avoid deleting good edits. [[User:Freqmax|Freqmax]] 17:33, 8 September 2007 (PDT)<br />
<br />
Thank you, Freqmax.<br />
--[[User:DavidCary|DavidCary]] 22:29, 22 September 2007 (PDT)<br />
<br />
'''Aloha from Oviedo, Florida''' Yesterday I changed my email in My Preferences, to reflect my current address. I waited for the confirmation email, but it didn't arrive for several hours. I tried re-sending it a few times, but eventually stopped watching for it. So of course, this morning there were several confirmation emails sitting in my inbox. Most had expired, but one was still valid and so I am confirmed. I found a message that my Talk page had changed. Someone had replaced your first reply with a bunch of gay porn sites. I was able to get the proper text back in place and noticed you had been doing the same over the last several weeks. I just wanted to thank you and say I hope to be able to do more of my own weeding in this area. I guess I should check the rest of my posts.<br />
<br />
Keep up the good work.--[[User:RogerAF|RAF]] 07:55, 24 October 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:RogerAF&diff=10054User talk:RogerAF2007-10-24T14:27:36Z<p>RogerAF: </p>
<hr />
<div>Aloha from Honolulu,<br />
I have several areas of interest. I've been servicing recording studios here in honolulu, since the late '80s. Also concert sound, video projection, and theatrical lighting systems. I play electric rock-blues guitar and know what guitar players want from their Marshall amps. And I do recording engineering and production, so I know what recording engineers need from their monitor amps and speakers.<br />
<br />
I have several projects I'm currently working on. And several ideas I want to develop ito new projects. I was thinking about some of those when I came across this site. It seems so serendipitous, I just had to join and write something.<br />
<br />
I've spent the last week or so working on PC board layouts of several voltage regulator designs I've built and used over the years. I built a replacement for a recording console power supply regulator, that has been working now for near 10 years. I couldn't find the high current regulators that the original design used, so I used a pair of 723 ICs and external pass transistors and made my own substitute. The 723 has been bery bery goot to me! I used another pair of them to make a bench supply that adjusts from 12V to 35V plus and minus are individually adjustable and the pass devices have a 20A rating. I use this to experiment with various discrete op amp designs. A modern version of the Jensen 990 is my goal.<br />
<br />
I've also recently built my first switchmode regulator based on TIs TL494 PWM controller IC. My experience with switching regulators is limited. I never had to repair one, only replace the complete unit, so I'm having to learn about them on my own. I've collected a lot of documentation and learned about buck, boost, buck-boost, fly-back etc. But it is all "book learning" as opposed to "hands on" at this point.<br />
<br />
I thought these regulators might interest someone. I will post the schematics and artwork here eventually, but I need to find out more about how that is done. If anyone is interested, let me know.<br />
<br />
Aloha, RAF<br />
<br />
== welcome ==<br />
<br />
Aloha, RogerAF.<br />
Welcome to Open Circuits.<br />
<br />
I hope you enjoy reading OpenCircuits and sharing your knowledge with us.<br />
<br />
A few tips:<br />
* You can "sign" your contributions by typing four tildes "<nowiki>~~~~</nowiki>" at the end.<br />
* Be bold with your editing. If you add information that really belongs on some other page of this wiki (or on some other wiki entirely), or you accidentally delete some crucial stuff, it's fairly easy for anyone to fix it. Please feel free to revert or otherwise fix-up any of my edits that turn out to be erroneous and/or misguided.<br />
* We are all volunteers here.<br />
<br />
Thank you for sharing your experiences here.<br />
I also have a bunch of "book learning" about switching regulators.<br />
<br />
Have you seen [http://switcher.national.com/ National's "simple switcher"]?<br />
The web application is nice for taking specifications like "up to 3 A output current", input voltage, and output voltage, and rapidly converting it to a circuit that National guarantees will work -- rather than fiddling around with prototypes for a few days.<br />
<br />
Have you seen [http://romanblack.com/smps/a04.htm The 3-transistor Black regulator]?<br />
Or the [http://romanblack.com/smps/conv.htm +5v to +13v Converter] also by Roman Black?<br />
It makes me wonder why I used to think switchmode regulators required a complicated IC to control them.<br />
<br />
Should we start a page on switching regulators here at Open Circuits?<br />
<br />
--[[User:DavidCary|DavidCary]] 00:35, 18 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
Hi David,<br />
In response to your question re a switching regulators page. I'd vote yea and expect that a linear page should be its partner. Given that the two types are so different in approach and conception. Linear regulators are very easy for me to understand, because of my years with audio equipment--most of which used linear supplies. Switching supplies are found in audio processing units, but the repair was generally to swap in a new card rather than trouble shoot for bad components.<br />
<br />
I haven't done anything with switching regulators other than building my first with a TI TL494 PWM controller IC. I looked at Roman Black's designs (Thanks for that turn on) what elegant simplicity! I'm in awe. I am happy to contribute to a linear regulators page--I have several discrete opamp based designs for dual tracking supplies etc. I'd like to see more switching designs, to expand my own knowledge and raise my conciousness. I've peeked at National's online design software, but never took the time to try anything.<br />
<br />
I have a little project that requires +3V, +5V, and +&- 15V. I'm trying out TI's 2W DC/DC converters: DCP020515, DCP020503, and TPS5430 Step Down Converter for that application, but it's on a back burner for a while. If anyone has any experience with these I'd like to hear about it.<br />
<br />
I've just been going through the documents I've downloaded and the samples I have on hand from Texas Instruments. The more I think about it, the more a page for switching regulators makes sense. I think it should be broken into different manufacturers offerings with a cross reference at the beginning or the end--assuming there is crossing. There may be more differences than duplications--I don't know, so that is something to be researched. This should be presented to the whole community for feedback.<br />
<br />
[[User:RogerAF|RAF]] 00:28, 23 May 2007 (PDT)<br />
<br />
----<br />
<br />
I responded to your question on [[User talk:DavidCary]].<br />
I responded there, rather than here, because the last time I put half of a conversation in one place, and the other half in another place, I only confused myself :-).<br />
--[[User:DavidCary|DavidCary]] 10:22, 23 May 2007 (PDT)<br />
<br />
== editing line drawings ==<br />
<br />
For editing general line drawings,<br />
the best editor I've found is "inkscape".<br />
Download it for free ( http://inkscape.org/ ).<br />
<br />
Some people use inkscape even for sketching schematics.<br />
Other people prefer a specialized [[techniques#software_design_tools | schematic editor]].<br />
<br />
Congratulations, you've already posted more images to Open Circuits than I have :-).<br />
<br />
--[[User:DavidCary|DavidCary]] 12:51, 23 May 2007 (PDT)<br />
<br />
== switching power supply design ==<br />
<br />
[http://smps.us/ "SMPS switching power supply design: circuits, schematics, PCBs, electrical engineering reference, software, and other free online resources" ] edited by Lazar Rozenblat.<br />
<br />
== writing on wiki ==<br />
<br />
Some of my favorite pages about writing on wiki are:<br />
<br />
* [http://communitywiki.org/SentenceToPageToSectionToWiki "sentence to page to section to wiki"]<br />
* [http://communitywiki.org/BigBucketsFirstExplanation "big buckets first" explanation]<br />
* [http://communitywiki.org/PlainTalk Plain Talk]<br />
<br />
I'm dropping little snippets of information here, even though I plan to separate them out into another page someday.<br />
The "sentence to page" and the "big buckets first" essays should explain why I do this, rather than creating a fresh page now and placing 2 snippets of information into it.<br />
<br />
--[[User:68.0.120.35|68.0.120.35]] 20:54, 11 June 2007 (PDT)<br />
<br />
----<br />
<br />
'''Anonymous Edits'''<br />
<br />
To who ever edited this page earlier. You did no favors to anyone here. You did not contribute anything. You removed information that others spent time and thought composing and sharing with the community. If you did this by accident, you owe it to yourself and everyone else (not only on this wiki, but on every wiki) to learn how to use the tools properly, so you don't damage things.<br />
<br />
If you did this knowing what you do, then you are a malicious prankster and should be banned from the site.<br />
<br />
I prefer to give you the benefit of the doubt, so in the future, be more careful.<br />
<br />
[[User:RogerAF|RAF]] 06:09, 9 July 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:DavidCary&diff=5168User talk:DavidCary2007-07-09T13:23:10Z<p>RogerAF: /* spammers */</p>
<hr />
<div>Why don't you help finish my programmable chip eeg project and then use what you learned and the results to then create your own project. Programmers like to reuse working modulas instead of reinventing the wheel.<br />
<br />
<br />
<br />
<br />
== spammers ==<br />
<br />
I think I know how to dramatically reduce the amount of linkspam on the website i think if the administrators on this site protect pages that are frequently spammed such as [[Open Circuits talk:Community Portal]] that will reduce the amount of spam on this site because the spammers will not be able to edit those pages.--[[User:71.234.233.163|71.234.233.163]] 08:21, 2 June 2007 (PDT)<br />
<br />
:I just signed up a few minutes ago and noticed that there seems to be a lot of linkspam being placed by unregistered users. I don't want to exclude folk, but would only allowing registered users to edit cut down some of the spam? [[User:Autarch|Autarch]] 09:53, 13 June 2007 (PDT)<br />
<br />
::You are right.<br />
::Certainly that is one way to cut down on spam, and perhaps I will be forced to do that soon.<br />
<br />
Another way, as you can see from [[Special:Ipblocklist]], I've been banning a bunch of anonymous spammers.<br />
<br />
:But is there another, better way to reduce spam?<br />
<br />
:I want to avoid a problem I am starting to notice.<br />
:Sometimes I see a tiny little typo or technopropisms or some other tiny little thing that I could easily fix<br />
:( http://communitywiki.org/WhyWikiWorks ).<br />
:But someone has built a huge barrier that prevents me from helping.<br />
:We want a system in a way that makes it very easy for anyone to help us.<br />
:Certainly too much spam is leaking through just now, but I don't want to go to the opposite extreme and make people go through a big complicated procedure in order to improve a schematic or fix a typo.<br />
:--[[User:DavidCary|DavidCary]] 21:39, 21 June 2007 (PDT)<br />
<br />
::That's a very noble way of thinking. I also like to be able to edit anonymously... There are enough sites you have to register for already. --SebDE<br />
<br />
::I know how to greatly reducethe amount of spam without stopping anomyomus ips from editing you can install a spam filter [http://wiki.cotch.net/index.php/Spam_filter like the one at my website EvoWiki] we usually dont get much spam at EvoWiki because we have a spam filter.--[[User:71.234.233.163|71.234.233.163]] 15:01, 22 June 2007 (PDT)<br />
<br />
:::Indeed, a black list based on words is the way to go here. BTW this seems to be an extension you need to install from [http://meta.wikimedia.org/wiki/SpamBlacklist_extension there]<br />
:::And an easy way to monitor for spam can help, too. The spam cops around here might want to check out those [http://en.wikipedia.org/wiki/Wikipedia:Tools/Editing_tools wiki editing tools] ;) --SebDE<br />
::::Bummer, they recently moved the BalckList Extension to the Extension namespace http://www.mediawiki.org/wiki/Extension:SpamBlacklist<br />
::::Anyways, if you've problem with installing that or in doubt of maintaining - I run several mediawikis for private use and am quite advanced with regexes, although only very simple ones are needed for the BlackList.<br />
::::--SebDE<br />
:::::Well I just digged through the code of the Extension and spotted a spam filter option that is already there in the MediaWiki software. It would involve edititing the configuration for any new spam pattern, tough. --SebDE<br />
<br />
'''Anonymous Edits?'''<br />
Aloha from Honolulu David,<br />
I just got an email saying my page had been edited by an anonymous user. I don't know who this is, there is nothing his/her page. I would not be complainig if the edits had improved things, but all they did was delete information. Perhaps it is their sense of humor.<br />
I am glad there is the record of changes made, so I can try to recover what was removed. Just to let you know that apparently spammers are not all you have to worry about.<br />
<br />
Roger<br />
[[User:RogerAF|RAF]] 05:58, 9 July 2007 (PDT)<br />
<br />
P. S.<br />
<br />
I just finished replacing what had been rmoved. Again, I'm grateful for the changes records. I also left a note to whoever did it. I think possibly it was unintentional. I hope that's the case.<br />
<br />
It occurred to me that perhaps editing should not be allowed by anonymous users. Perhaps there could be a special page that allowed anonimity, but require identification from anyone who wants to perform edits on pages that others have posted.<br />
<br />
I don't know how you'd acomplish it. I'm just a bit po'd that this can happen. He could have easily deleted the whole page. I'm glad it was easy to repair, but I will be moving come the middle of August and I may not have email for a week or two, possibly longer. So if something like this happened then, I would not know for some time. Then it would be a problem. Forgive my rant, but see my point? I'll leave it at that and check back later.<br />
<br />
[[User:RogerAF|RAF]] 06:23, 9 July 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:RogerAF&diff=5167User talk:RogerAF2007-07-09T13:09:24Z<p>RogerAF: </p>
<hr />
<div>Aloha from Honolulu,<br />
I have several areas of interest. I've been servicing recording studios here in honolulu, since the late '80s. Also concert sound, video projection, and theatrical lighting systems. I play electric rock-blues guitar and know what guitar players want from their Marshall amps. And I do recording engineering and production, so I know what recording engineers need from their monitor amps and speakers.<br />
<br />
I have several projects I'm currently working on. And several ideas I want to develop ito new projects. I was thinking about some of those when I came across this site. It seems so serendipitous, I just had to join and write something.<br />
<br />
I've spent the last week or so working on PC board layouts of several voltage regulator designs I've built and used over the years. I built a replacement for a recording console power supply regulator, that has been working now for near 10 years. I couldn't find the high current regulators that the original design used, so I used a pair of 723 ICs and external pass transistors and made my own substitute. The 723 has been bery bery goot to me! I used another pair of them to make a bench supply that adjusts from 12V to 35V plus and minus are individually adjustable and the pass devices have a 20A rating. I use this to experiment with various discrete op amp designs. A modern version of the Jensen 990 is my goal.<br />
<br />
I've also recently built my first switchmode regulator based on TIs TL494 PWM controller IC. My experience with switching regulators is limited. I never had to repair one, only replace the complete unit, so I'm having to learn about them on my own. I've collected a lot of documentation and learned about buck, boost, buck-boost, fly-back etc. But it is all "book learning" as opposed to "hands on" at this point.<br />
<br />
I thought these regulators might interest someone. I will post the schematics and artwork here eventually, but I need to find out more about how that is done. If anyone is interested, let me know.<br />
<br />
Aloha, RAF<br />
<br />
== welcome ==<br />
<br />
Aloha, RogerAF.<br />
Welcome to Open Circuits.<br />
<br />
I hope you enjoy reading OpenCircuits and sharing your knowledge with us.<br />
<br />
A few tips:<br />
* You can "sign" your contributions by typing four tildes "<nowiki>~~~~</nowiki>" at the end.<br />
* Be bold with your editing. If you add information that really belongs on some other page of this wiki (or on some other wiki entirely), or you accidentally delete some crucial stuff, it's fairly easy for anyone to fix it. Please feel free to revert or otherwise fix-up any of my edits that turn out to be erroneous and/or misguided.<br />
* We are all volunteers here.<br />
<br />
Thank you for sharing your experiences here.<br />
I also have a bunch of "book learning" about switching regulators.<br />
<br />
Have you seen [http://switcher.national.com/ National's "simple switcher"]?<br />
The web application is nice for taking specifications like "up to 3 A output current", input voltage, and output voltage, and rapidly converting it to a circuit that National guarantees will work -- rather than fiddling around with prototypes for a few days.<br />
<br />
Have you seen [http://romanblack.com/smps/a04.htm The 3-transistor Black regulator]?<br />
Or the [http://romanblack.com/smps/conv.htm +5v to +13v Converter] also by Roman Black?<br />
It makes me wonder why I used to think switchmode regulators required a complicated IC to control them.<br />
<br />
Should we start a page on switching regulators here at Open Circuits?<br />
<br />
--[[User:DavidCary|DavidCary]] 00:35, 18 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
Hi David,<br />
In response to your question re a switching regulators page. I'd vote yea and expect that a linear page should be its partner. Given that the two types are so different in approach and conception. Linear regulators are very easy for me to understand, because of my years with audio equipment--most of which used linear supplies. Switching supplies are found in audio processing units, but the repair was generally to swap in a new card rather than trouble shoot for bad components.<br />
<br />
I haven't done anything with switching regulators other than building my first with a TI TL494 PWM controller IC. I looked at Roman Black's designs (Thanks for that turn on) what elegant simplicity! I'm in awe. I am happy to contribute to a linear regulators page--I have several discrete opamp based designs for dual tracking supplies etc. I'd like to see more switching designs, to expand my own knowledge and raise my conciousness. I've peeked at National's online design software, but never took the time to try anything.<br />
<br />
I have a little project that requires +3V, +5V, and +&- 15V. I'm trying out TI's 2W DC/DC converters: DCP020515, DCP020503, and TPS5430 Step Down Converter for that application, but it's on a back burner for a while. If anyone has any experience with these I'd like to hear about it.<br />
<br />
I've just been going through the documents I've downloaded and the samples I have on hand from Texas Instruments. The more I think about it, the more a page for switching regulators makes sense. I think it should be broken into different manufacturers offerings with a cross reference at the beginning or the end--assuming there is crossing. There may be more differences than duplications--I don't know, so that is something to be researched. This should be presented to the whole community for feedback.<br />
<br />
RAF 00:28, 23 May 2007 (PDT)<br />
<br />
I responded to your question on User talk:DavidCary. I responded there, rather than here, because the last time I put half of a conversation in one place, and the other half in another place, I only confused myself :-). --DavidCary 10:22, 23 May 2007 (PDT)<br />
editing line drawings<br />
<br />
For editing general line drawings, the best editor I've found is "inkscape". Download it for free ( http://inkscape.org/ ).<br />
<br />
Some people use inkscape even for sketching schematics. Other people prefer a specialized schematic editor.<br />
<br />
Congratulations, you've already posted more images to Open Circuits than I have :-).<br />
<br />
--DavidCary 12:51, 23 May 2007 (PDT)<br />
switching power supply design<br />
<br />
"SMPS switching power supply design: circuits, schematics, PCBs, electrical engineering reference, software, and other free online resources" edited by Lazar Rozenblat.<br />
writing on wiki<br />
<br />
Some of my favorite pages about writing on wiki are:<br />
<br />
* "sentence to page to section to wiki"<br />
* "big buckets first" explanation<br />
* Plain Talk <br />
<br />
I'm dropping little snippets of information here, even though I plan to separate them out into another page someday. The "sentence to page" and the "big buckets first" essays should explain why I do this, rather than creating a fresh page now and placing 2 snippets of information into it.<br />
<br />
--68.0.120.35 20:54, 11 June 2007 (PDT)<br />
<br />
'''Anonymous Edits'''<br />
<br />
To who ever edited this page earlier. You did no favors to anyone here. You did not contribute anything. You removed information that others spent time and thought composing and sharing with the community. If you did this by accident, you owe it to yourself and everyone else (not only on this wiki, but on every wiki) to learn how to use the tools properly, so you don't damage things.<br />
<br />
If you did this knowing what you do, then you are a malicious prankster and should be banned from the site.<br />
<br />
I prefer to give you the benefit of the doubt, so in the future, be more careful.<br />
<br />
[[User:RogerAF|RAF]] 06:09, 9 July 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:RogerAF&diff=5166User talk:RogerAF2007-07-09T13:02:20Z<p>RogerAF: /* welcome */</p>
<hr />
<div>Aloha from Honolulu,<br />
I have several areas of interest. I've been servicing recording studios here in honolulu, since the late '80s. Also concert sound, video projection, and theatrical lighting systems. I play electric rock-blues guitar and know what guitar players want from their Marshall amps. And I do recording engineering and production, so I know what recording engineers need from their monitor amps and speakers.<br />
<br />
I have several projects I'm currently working on. And several ideas I want to develop ito new projects. I was thinking about some of those when I came across this site. It seems so serendipitous, I just had to join and write something.<br />
<br />
I've spent the last week or so working on PC board layouts of several voltage regulator designs I've built and used over the years. I built a replacement for a recording console power supply regulator, that has been working now for near 10 years. I couldn't find the high current regulators that the original design used, so I used a pair of 723 ICs and external pass transistors and made my own substitute. The 723 has been bery bery goot to me! I used another pair of them to make a bench supply that adjusts from 12V to 35V plus and minus are individually adjustable and the pass devices have a 20A rating. I use this to experiment with various discrete op amp designs. A modern version of the Jensen 990 is my goal.<br />
<br />
I've also recently built my first switchmode regulator based on TIs TL494 PWM controller IC. My experience with switching regulators is limited. I never had to repair one, only replace the complete unit, so I'm having to learn about them on my own. I've collected a lot of documentation and learned about buck, boost, buck-boost, fly-back etc. But it is all "book learning" as opposed to "hands on" at this point.<br />
<br />
I thought these regulators might interest someone. I will post the schematics and artwork here eventually, but I need to find out more about how that is done. If anyone is interested, let me know.<br />
<br />
Aloha, RAF<br />
<br />
== welcome ==<br />
<br />
Aloha, RogerAF.<br />
Welcome to Open Circuits.<br />
<br />
I hope you enjoy reading OpenCircuits and sharing your knowledge with us.<br />
<br />
A few tips:<br />
* You can "sign" your contributions by typing four tildes "<nowiki>~~~~</nowiki>" at the end.<br />
* Be bold with your editing. If you add information that really belongs on some other page of this wiki (or on some other wiki entirely), or you accidentally delete some crucial stuff, it's fairly easy for anyone to fix it. Please feel free to revert or otherwise fix-up any of my edits that turn out to be erroneous and/or misguided.<br />
* We are all volunteers here.<br />
<br />
Thank you for sharing your experiences here.<br />
I also have a bunch of "book learning" about switching regulators.<br />
<br />
Have you seen [http://switcher.national.com/ National's "simple switcher"]?<br />
The web application is nice for taking specifications like "up to 3 A output current", input voltage, and output voltage, and rapidly converting it to a circuit that National guarantees will work -- rather than fiddling around with prototypes for a few days.<br />
<br />
Have you seen [http://romanblack.com/smps/a04.htm The 3-transistor Black regulator]?<br />
Or the [http://romanblack.com/smps/conv.htm +5v to +13v Converter] also by Roman Black?<br />
It makes me wonder why I used to think switchmode regulators required a complicated IC to control them.<br />
<br />
Should we start a page on switching regulators here at Open Circuits?<br />
<br />
--[[User:DavidCary|DavidCary]] 00:35, 18 May 2007 (PDT)<br />
<br />
----<br />
<br />
<br />
Hi David,<br />
In response to your question re a switching regulators page. I'd vote yea and expect that a linear page should be its partner. Given that the two types are so different in approach and conception. Linear regulators are very easy for me to understand, because of my years with audio equipment--most of which used linear supplies. Switching supplies are found in audio processing units, but the repair was generally to swap in a new card rather than trouble shoot for bad components.<br />
<br />
I haven't done anything with switching regulators other than building my first with a TI TL494 PWM controller IC. I looked at Roman Black's designs (Thanks for that turn on) what elegant simplicity! I'm in awe. I am happy to contribute to a linear regulators page--I have several discrete opamp based designs for dual tracking supplies etc. I'd like to see more switching designs, to expand my own knowledge and raise my conciousness. I've peeked at National's online design software, but never took the time to try anything.<br />
<br />
I have a little project that requires +3V, +5V, and +&- 15V. I'm trying out TI's 2W DC/DC converters: DCP020515, DCP020503, and TPS5430 Step Down Converter for that application, but it's on a back burner for a while. If anyone has any experience with these I'd like to hear about it.<br />
<br />
I've just been going through the documents I've downloaded and the samples I have on hand from Texas Instruments. The more I think about it, the more a page for switching regulators makes sense. I think it should be broken into different manufacturers offerings with a cross reference at the beginning or the end--assuming there is crossing. There may be more differences than duplications--I don't know, so that is something to be researched. This should be presented to the whole community for feedback.<br />
<br />
RAF 00:28, 23 May 2007 (PDT)<br />
<br />
I responded to your question on User talk:DavidCary. I responded there, rather than here, because the last time I put half of a conversation in one place, and the other half in another place, I only confused myself :-). --DavidCary 10:22, 23 May 2007 (PDT)<br />
editing line drawings<br />
<br />
For editing general line drawings, the best editor I've found is "inkscape". Download it for free ( http://inkscape.org/ ).<br />
<br />
Some people use inkscape even for sketching schematics. Other people prefer a specialized schematic editor.<br />
<br />
Congratulations, you've already posted more images to Open Circuits than I have :-).<br />
<br />
--DavidCary 12:51, 23 May 2007 (PDT)<br />
switching power supply design<br />
<br />
"SMPS switching power supply design: circuits, schematics, PCBs, electrical engineering reference, software, and other free online resources" edited by Lazar Rozenblat.<br />
writing on wiki<br />
<br />
Some of my favorite pages about writing on wiki are:<br />
<br />
* "sentence to page to section to wiki"<br />
* "big buckets first" explanation<br />
* Plain Talk <br />
<br />
I'm dropping little snippets of information here, even though I plan to separate them out into another page someday. The "sentence to page" and the "big buckets first" essays should explain why I do this, rather than creating a fresh page now and placing 2 snippets of information into it.<br />
<br />
--68.0.120.35 20:54, 11 June 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:DavidCary&diff=5165User talk:DavidCary2007-07-09T12:58:32Z<p>RogerAF: /* spammers */</p>
<hr />
<div>Why don't you help finish my programmable chip eeg project and then use what you learned and the results to then create your own project. Programmers like to reuse working modulas instead of reinventing the wheel.<br />
<br />
<br />
<br />
<br />
== spammers ==<br />
<br />
I think I know how to dramatically reduce the amount of linkspam on the website i think if the administrators on this site protect pages that are frequently spammed such as [[Open Circuits talk:Community Portal]] that will reduce the amount of spam on this site because the spammers will not be able to edit those pages.--[[User:71.234.233.163|71.234.233.163]] 08:21, 2 June 2007 (PDT)<br />
<br />
:I just signed up a few minutes ago and noticed that there seems to be a lot of linkspam being placed by unregistered users. I don't want to exclude folk, but would only allowing registered users to edit cut down some of the spam? [[User:Autarch|Autarch]] 09:53, 13 June 2007 (PDT)<br />
<br />
::You are right.<br />
::Certainly that is one way to cut down on spam, and perhaps I will be forced to do that soon.<br />
<br />
Another way, as you can see from [[Special:Ipblocklist]], I've been banning a bunch of anonymous spammers.<br />
<br />
:But is there another, better way to reduce spam?<br />
<br />
:I want to avoid a problem I am starting to notice.<br />
:Sometimes I see a tiny little typo or technopropisms or some other tiny little thing that I could easily fix<br />
:( http://communitywiki.org/WhyWikiWorks ).<br />
:But someone has built a huge barrier that prevents me from helping.<br />
:We want a system in a way that makes it very easy for anyone to help us.<br />
:Certainly too much spam is leaking through just now, but I don't want to go to the opposite extreme and make people go through a big complicated procedure in order to improve a schematic or fix a typo.<br />
:--[[User:DavidCary|DavidCary]] 21:39, 21 June 2007 (PDT)<br />
<br />
::That's a very noble way of thinking. I also like to be able to edit anonymously... There are enough sites you have to register for already. --SebDE<br />
<br />
::I know how to greatly reducethe amount of spam without stopping anomyomus ips from editing you can install a spam filter [http://wiki.cotch.net/index.php/Spam_filter like the one at my website EvoWiki] we usually dont get much spam at EvoWiki because we have a spam filter.--[[User:71.234.233.163|71.234.233.163]] 15:01, 22 June 2007 (PDT)<br />
<br />
:::Indeed, a black list based on words is the way to go here. BTW this seems to be an extension you need to install from [http://meta.wikimedia.org/wiki/SpamBlacklist_extension there]<br />
:::And an easy way to monitor for spam can help, too. The spam cops around here might want to check out those [http://en.wikipedia.org/wiki/Wikipedia:Tools/Editing_tools wiki editing tools] ;) --SebDE<br />
::::Bummer, they recently moved the BalckList Extension to the Extension namespace http://www.mediawiki.org/wiki/Extension:SpamBlacklist<br />
::::Anyways, if you've problem with installing that or in doubt of maintaining - I run several mediawikis for private use and am quite advanced with regexes, although only very simple ones are needed for the BlackList.<br />
::::--SebDE<br />
:::::Well I just digged through the code of the Extension and spotted a spam filter option that is already there in the MediaWiki software. It would involve edititing the configuration for any new spam pattern, tough. --SebDE<br />
<br />
'''Anonymous Edits?'''<br />
Aloha from Honolulu David,<br />
I just got an email saying my page had been edited by an anonymous user. I don't know who this is, ther is nothing his/her page. I would not be complainig if the edits had improved things, but all they did was delete information. Perhaps it is their sense of humor.<br />
I am glad there is the record of changes made, so I can try to recover what was removed. Just to let you know that apparently spammers are not all you have to worry about.<br />
<br />
Roger<br />
[[User:RogerAF|RAF]] 05:58, 9 July 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User:RogerAF&diff=5092User:RogerAF2007-07-05T02:56:56Z<p>RogerAF: </p>
<hr />
<div>'''Introduction'''<br />
<br />
Aloha from Honolulu,<br />
I found Open Circuits on or about May 15, 2007. I was searching the internet for "electronic breadboard" and found SparkFun Electronics which has a link to Open Circuits.<br />
<br />
I have an idea for some "building block" circuit boards that engineers and students can use for breadboarding. I just happen to need something like this myself, so maybe others can use them too. I couldn't find anything like I have in mind, so perhaps there is a market waitng to be created. I'd be happy to share the scematics and artwork (once they exist) and hope that others will share their ideas. Eventualy we could build a library of these that colleges and tech schools would use.<br />
<br />
So that is how I came to Open Circuits. It also happened to be at a time when I had just completed a project that had been hanging fire for several years. That is the artwork for some voltage regulator boards based on the LM723 IC. I have used these in several personal projects and also in some professional ones.<br />
<br />
My main gig here in Honolulu has been the installation and servicing of recording studios. I've been at it for the past 20 years. I had one client whose console power supply needed help. The voltage regulators were a high current (7 amp) device in a TO3 package. There was one each for the +15V and -15V rails. I'd replaced them once before, but this time I could not find the devices. (I forgot what the part number was.) So I decided to use a couple of LM723s which I had a large supply of (courtesy of another project that had not gotten off the ground). I used a 2N3055 transistor as the external series pass element for the positive side and tried to use its compliment 2N2955 for the negative side. But I found I could not get the current required. I switched to a Darlington device and the problem went away, so I used a complimentary pair of 15 amp Darlington transistors in TO3 packages. The unit has now been working for nearly 10 years. I plan to share these designs here once I have a better understanding of how to upload files and what formats to use.<br />
<br />
My other interests are in embedded processors and computer programming. I used to do a lot with Pascal and Assembly back in the DOS days. I started with Turbo Pascal 3 and Turbo Assembler, I went up to Turbo Pascal version 7 before Windows came along and made it more complicated. I started to learn C++, but got out of programming for several years. I got back into it again when embedded devices started to proliferate. I brushed off my C++, but find I'm mostly using plain C with these things. That and Assembly when something needs to go as fast as it can.<br />
<br />
I'll continue with this as time allows.<br />
<br />
Aloha,<br />
Roger<br />
[[User:RogerAF|RAF]] 17:45, 18 May 2007 (PDT)<br />
<br />
Hello again,<br />
I fiished my article as well as another article I want to include. The second is not mine, but is so old I can't find it anywhere, but for the copy I have in my files. The title is: "The Many-Talented 723" and the author is Glenn Prescott. I've searched the web without finding any reference to it. I have a xerox copy from the mid 1980s. Not a very good copy, but I scanned it and ran an OCR program on it. I still had to do a lot of editing to help out the OCR. Then I had to do all the images over again myself. I kept them as close to the originals as I could, except for scale, mine are a little larger and this more legible. My text is also full page instead of the 4 column format of the original. So now I'm ready to put this all together. I uploaded a symbol for the image of the 723. Otherwise it would be a picture of a 14-pin DIP. I'm going to see if I can copy it to this page...<br />
<br />
[[Image:UA723CN_Symbol.gif]]<br />
<br />
OK, that wasn't too bad, except for forgetting what the name was...<br />
Now let's see about the Component article.<br />
[[User:RogerAF|RAF]]<br />
<br />
<br />
Well, I had to write the question to David Cary. I couldn't figure out how to make a stand-alone article for the 723. What I did was put it in the "discussion page for the image file. That is just a temporary solution and there isn't any room for my in-depth text on using the 723 anfd Glenn Prescott's article "The Many-Talented 723". Hopefully David can show me how to make it happen and all will be well...<br />
<br />
<br />
I figured out how to post a new article. I searched for "New Article" and of course the search returned with "no such thing found", but it has "thing" in red. Aha! it is an internal link. Click on it and it takes you to another page that says basically "Hi this is not the page of "thing" because "thing" does not exist. If you would like to create "thing" click on the edit button. So I did and was able to copy/paste my article and save it.<br />
<br />
For anyone who was holding their breath waiting for my promised articles, here is a link to the first:<br />
<br />
[[The 723 Voltage Regulator]]<br />
<br />
The second has been up for a while: <br />
<br />
[[My Experience With The 723]]<br />
<br />
And I just uploaded some schematics to it, so if anyone was wondering how to hook some of these up, here's a clue or two. (Hint: go to "My Experience With The 723" for the links) I have some others still to go and then there are some Printed Circuit designs that go with these schematics, I have a little more work to finish them, but they will get here.<br />
<br />
'''LCD Display'''<br />
<br />
I've been working on a metering instrument that needs a graphic LCD for the display. I've decided to share my experience making the display with Open Circuits. I just received the unit, so I'm excited about it. I'll start working on the design over the weekend. The unit needs an inverter for the CCF lamps and a controller to provide an interface between the display and a micro. I'll get the project started and open it up for ideas.<br />
<br />
--[[User:RogerAF|RAF]] 00:10, 20 June 2007 (PDT)<br />
<br />
'''Update on What's Happening'''<br />
<br />
Here is an update. Nobody responded to any of my emails asking what inverter will work with the LCD I purchased. The unit is a Sharp LM32C04P 320x240 Color LCD Display. The color is one bit each RGB, so a total of eight colors including black and white are possible. It needs an inverter and a controller. I was able to get a hold of a specifications data sheet showing all the signals and timing requirements. This has enough information to design a controller circuit and if I must, an inverter as well. However, I think I will purchase an inverter once my funds recover.<br />
I have already completed a couple of schematics for a controller circuit using a 32K x 8 SRAM and a counter, so the MCU can concentrate on loading the SRAM with data to display and the counter will do the drudge work of stepping through the addresses and sending the data to the LCD bus. The MCU will also have to talk to whatever device is using the display. So I have to figure out how to make it be an interface as well.<br />
For the controller I decided to try using Microchip's 16-bit family of devices and purchased an MPLAB ICD2 and 16-Bit 28-Pin Starter Development Board. I am currently working my way through the demo code and data sheets, to get an understanding of both the devices and the tools. One won't work without the other and there is always at least a 6-week learning curve (for me) before I'm confident enough to work without the references open beside me.<br />
Just when it seemed like progress was going to be swift and sure, my mother and brother and family decided to sell the family house and move to the big island. I will have to find another place to live and my sights are turning towards Orlando Florida. I have friends there and it looks like there is work for electronics engineers there. So my life is going to be going through a bit of upheaval until I get moved and setteled in somewhere. I'm going to try to continue my studies with the Microchip devices, so I won't be starting up again from scratch.<br />
I hope to be able to drop in here now and then over the next 3 months or so, but it will probably take at least that long to get setteled in at a new place. Meanwhile if anyone has any ideas, suggestions, or questions, post them here and I'll try to check in often enough to give a timely response.<br />
<br />
[[User:RogerAF|RAF]] 19:56, 4 July 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User:RogerAF&diff=4459User:RogerAF2007-06-20T07:38:07Z<p>RogerAF: </p>
<hr />
<div>'''Introduction'''<br />
<br />
Aloha from Honolulu,<br />
I found Open Circuits on or about May 15, 2007. I was searching the internet for "electronic breadboard" and found SparkFun Electronics which has a link to Open Circuits.<br />
<br />
I have an idea for some "building block" circuit boards that engineers and students can use for breadboarding. I just happen to need something like this myself, so maybe others can use them too. I couldn't find anything like I have in mind, so perhaps there is a market waitng to be created. I'd be happy to share the scematics and artwork (once they exist) and hope that others will share their ideas. Eventualy we could build a library of these that colleges and tech schools would use.<br />
<br />
So that is how I came to Open Circuits. It also happened to be at a time when I had just completed a project that had been hanging fire for several years. That is the artwork for some voltage regulator boards based on the LM723 IC. I have used these in several personal projects and also in some professional ones.<br />
<br />
My main gig here in Honolulu has been the installation and servicing of recording studios. I've been at it for the past 20 years. I had one client whose console power supply needed help. The voltage regulators were a high current (7 amp) device in a TO3 package. There was one each for the +15V and -15V rails. I'd replaced them once before, but this time I could not find the devices. (I forgot what the part number was.) So I decided to use a couple of LM723s which I had a large supply of (courtesy of another project that had not gotten off the ground). I used a 2N3055 transistor as the external series pass element for the positive side and tried to use its compliment 2N2955 for the negative side. But I found I could not get the current required. I switched to a Darlington device and the problem went away, so I used a complimentary pair of 15 amp Darlington transistors in TO3 packages. The unit has now been working for nearly 10 years. I plan to share these designs here once I have a better understanding of how to upload files and what formats to use.<br />
<br />
My other interests are in embedded processors and computer programming. I used to do a lot with Pascal and Assembly back in the DOS days. I started with Turbo Pascal 3 and Turbo Assembler, I went up to Turbo Pascal version 7 before Windows came along and made it more complicated. I started to learn C++, but got out of programming for several years. I got back into it again when embedded devices started to proliferate. I brushed off my C++, but find I'm mostly using plain C with these things. That and Assembly when something needs to go as fast as it can.<br />
<br />
I'll continue with this as time allows.<br />
<br />
Aloha,<br />
Roger<br />
[[User:RogerAF|RAF]] 17:45, 18 May 2007 (PDT)<br />
<br />
Hello again,<br />
I fiished my article as well as another article I want to include. The second is not mine, but is so old I can't find it anywhere, but for the copy I have in my files. The title is: "The Many-Talented 723" and the author is Glenn Prescott. I've searched the web without finding any reference to it. I have a xerox copy from the mid 1980s. Not a very good copy, but I scanned it and ran an OCR program on it. I still had to do a lot of editing to help out the OCR. Then I had to do all the images over again myself. I kept them as close to the originals as I could, except for scale, mine are a little larger and this more legible. My text is also full page instead of the 4 column format of the original. So now I'm ready to put this all together. I uploaded a symbol for the image of the 723. Otherwise it would be a picture of a 14-pin DIP. I'm going to see if I can copy it to this page...<br />
<br />
[[Image:UA723CN_Symbol.gif]]<br />
<br />
OK, that wasn't too bad, except for forgetting what the name was...<br />
Now let's see about the Component article.<br />
[[User:RogerAF|RAF]]<br />
<br />
<br />
Well, I had to write the question to David Cary. I couldn't figure out how to make a stand-alone article for the 723. What I did was put it in the "discussion page for the image file. That is just a temporary solution and there isn't any room for my in-depth text on using the 723 anfd Glenn Prescott's article "The Many-Talented 723". Hopefully David can show me how to make it happen and all will be well...<br />
<br />
<br />
I figured out how to post a new article. I searched for "New Article" and of course the search returned with "no such thing found", but it has "thing" in red. Aha! it is an internal link. Click on it and it takes you to another page that says basically "Hi this is not the page of "thing" because "thing" does not exist. If you would like to create "thing" click on the edit button. So I did and was able to copy/paste my article and save it.<br />
<br />
For anyone who was holding their breath waiting for my promised articles, here is a link to the first:<br />
<br />
[[The 723 Voltage Regulator]]<br />
<br />
The second has been up for a while: <br />
<br />
[[My Experience With The 723]]<br />
<br />
And I just uploaded some schematics to it, so if anyone was wondering how to hook some of these up, here's a clue or two. (Hint: go to "My Experience With The 723" for the links) I have some others still to go and then there are some Printed Circuit designs that go with these schematics, I have a little more work to finish them, but they will get here.<br />
<br />
'''LCD Display'''<br />
<br />
I've been working on a metering instrument that needs a graphic LCD for the display. I've decided to share my experience making the display with Open Circuits. I just received the unit, so I'm excited about it. I'll start working on the design over the weekend. The unit needs an inverter for the CCF lamps and a controller to provide an interface between the display and a micro. I'll get the project started and open it up for ideas.<br />
<br />
--[[User:RogerAF|RAF]] 00:10, 20 June 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User:RogerAF&diff=4458User:RogerAF2007-06-20T07:10:53Z<p>RogerAF: </p>
<hr />
<div>'''Introduction'''<br />
<br />
Aloha from Honolulu,<br />
I found Open Circuits on or about May 15, 2007. I was searching the internet for "electronic breadboard" and found SparkFun Electronics which has a link to Open Circuits.<br />
<br />
I have an idea for some "building block" circuit boards that engineers and students can use for breadboarding. I just happen to need something like this myself, so maybe others can use them too. I couldn't find anything like I have in mind, so perhaps there is a market waitng to be created. I'd be happy to share the scematics and artwork (once they exist) and hope that others will share their ideas. Eventualy we could build a library of these that colleges and tech schools would use.<br />
<br />
So that is how I came to Open Circuits. It also happened to be at a time when I had just completed a project that had been hanging fire for several years. That is the artwork for some voltage regulator boards based on the LM723 IC. I have used these in several personal projects and also in some professional ones.<br />
<br />
My main gig here in Honolulu has been the installation and servicing of recording studios. I've been at it for the past 20 years. I had one client whose console power supply needed help. The voltage regulators were a high current (7 amp) device in a TO3 package. There was one each for the +15V and -15V rails. I'd replaced them once before, but this time I could not find the devices. (I forgot what the part number was.) So I decided to use a couple of LM723s which I had a large supply of (courtesy of another project that had not gotten off the ground). I used a 2N3055 transistor as the external series pass element for the positive side and tried to use its compliment 2N2955 for the negative side. But I found I could not get the current required. I switched to a Darlington device and the problem went away, so I used a complimentary pair of 15 amp Darlington transistors in TO3 packages. The unit has now been working for nearly 10 years. I plan to share these designs here once I have a better understanding of how to upload files and what formats to use.<br />
<br />
My other interests are in embedded processors and computer programming. I used to do a lot with Pascal and Assembly back in the DOS days. I started with Turbo Pascal 3 and Turbo Assembler, I went up to Turbo Pascal version 7 before Windows came along and made it more complicated. I started to learn C++, but got out of programming for several years. I got back into it again when embedded devices started to proliferate. I brushed off my C++, but find I'm mostly using plain C with these things. That and Assembly when something needs to go as fast as it can.<br />
<br />
I'll continue with this as time allows.<br />
<br />
Aloha,<br />
Roger<br />
[[User:RogerAF|RAF]] 17:45, 18 May 2007 (PDT)<br />
<br />
Hello again,<br />
I fiished my article as well as another article I want to include. The second is not mine, but is so old I can't find it anywhere, but for the copy I have in my files. The title is: "The Many-Talented 723" and the author is Glenn Prescott. I've searched the web without finding any reference to it. I have a xerox copy from the mid 1980s. Not a very good copy, but I scanned it and ran an OCR program on it. I still had to do a lot of editing to help out the OCR. Then I had to do all the images over again myself. I kept them as close to the originals as I could, except for scale, mine are a little larger and this more legible. My text is also full page instead of the 4 column format of the original. So now I'm ready to put this all together. I uploaded a symbol for the image of the 723. Otherwise it would be a picture of a 14-pin DIP. I'm going to see if I can copy it to this page...<br />
<br />
[[Image:UA723CN_Symbol.gif]]<br />
<br />
OK, that wasn't too bad, except for forgetting what the name was...<br />
Now let's see about the Component article.<br />
[[User:RogerAF|RAF]]<br />
<br />
<br />
Well, I had to write the question to David Cary. I couldn't figure out how to make a stand-alone article for the 723. What I did was put it in the "discussion page for the image file. That is just a temporary solution and there isn't any room for my in-depth text on using the 723 anfd Glenn Prescott's article "The Many-Talented 723". Hopefully David can show me how to make it happen and all will be well...<br />
<br />
<br />
I figured out how to post a new article. I searched for "New Article" and of course the search returned with "no such thing found", but it has "thing" in red. Aha! it is an internal link. Click on it and it takes you to another page that says basically "Hi this is not the page of "thing" because "thing" does not exist. If you would like to create "thing" click on the edit button. So I did and was able to copy/paste my article and save it.<br />
<br />
For anyone who was holding their breath waiting for my promised articles, here is a link to the first:<br />
<br />
[[The 723 Voltage Regulator]]<br />
<br />
The second has been up for a while: <br />
<br />
[[My Experience With The 723]]<br />
<br />
And I just uploaded some schematics to it, so if anyone was wondering how to hook some of these up, here's a clue or two. (Hint: go to "My Experience With The 723" for the links) I have some others still to go and then there are some Printed Circuit designs that go with these schematics, I have a little more work to finish them, but they will get here.<br />
<br />
--[[User:RogerAF|RAF]] 00:10, 20 June 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=Pos_723_PNP_Reg.jpg&diff=4457Pos 723 PNP Reg.jpg2007-06-20T07:00:20Z<p>RogerAF: </p>
<hr />
<div>Back to: [[My Experience With The 723]]<br />
[[Image:Pos_723_PNP_Reg.jpg]]</div>RogerAFhttp://www.opencircuits.com/index.php?title=My_Experience_With_The_723&diff=4456My Experience With The 7232007-06-20T06:59:10Z<p>RogerAF: </p>
<hr />
<div>== My Experience With the 723 Voltage Regulator IC ==<br />
<br />
'''Introduction:'''<br />
<br />
I came across [[The 723 Voltage Regulator]] in the 1980s and thought it was much too complicated to use. I liked the 3-terminal regulators and stayed with them until I had to make a power supply that would handle more current than they could supply. In the mid ‘80s I’d come across a copy of an article called “The Many Talented 723" by Glen Prescott. I don’t know where this was published and I’ve been unable to locate it through Google. However I still have my copy and I decided it was worth scanning and cleaning up the figures, so I can share it with the world.<br />
<br />
There are a couple of companies who make the device, that describe it in their data sheet titles as a “Precision Voltage Regulator”. This is what it is. If you were to design a voltage regulator from scratch, using discrete components. You’d want to end up with something like the 723. I’m not going to go into detail about it, because the data sheets and Mr. Prescott’s article do that very well already. I just want to share some of my experiences in the use of it.<br />
<br />
<br />
'''My First Mixer Power Supply:'''<br />
<br />
I built a little microphone mixer while I was in electronics school and I needed a power supply for it. I had a pair of LM723 ICs in a drawer, but I’d never worked with the chip. I decided that I should learn about it. The National Semiconductor Linear data book showed a lot of different ways to use it and decided to build a plus and minus 15 volt supply with external pass devices. I included trimmers for fine tuning the outputs and I had a little aluminum case that I could fit the transformer, rectifier, filter capacitors, and PC board into. I used a sharpie pen and drew the layout by hand except for the IC patterns. I etched the board and assembled it. It powered my mixer very nicely and I got an A in that class.<br />
<br />
Last year I started experimenting with an Analog Devices AD7329–a 13-bit, 8 channel A to D converter which requires ±15V as well as 5V supplies. I dusted my little power supply off (it is over 20 years old now) tuned it on and checked the outputs. I thought I’d probably need to adjust the trimmers some, but even after sitting for the last 20 years, it was measuring +14.998V and -15.01V. I was very impressed and decided it was too nice to leave in a box. So it is out of retirement and I use it for my experiments on my bench whenever I’m working with op-amps that need ±15V.<br />
<br />
<br />
'''Second Mixer Power Supply:'''<br />
<br />
I service several recording studios here in Honolulu. One of my clients has a console whose power supply failed. It had failed before and I’d replaced the regulators, which were high current (7 amps) devices in TO3 packages. But the last time it failed I could not find replacements. I’ve forgotten the part number of the device, but it does not seem to be made any more and no one has produced a substitute.<br />
<br />
My client was understandably upset. Recording studios need to have working equipment–especially the mixing console. I told him I’d need at least 48 hours if not 72 to build replacement regulators. He said to hurry.<br />
<br />
I used the same circuit as in my little mixer supply above. I hand wired it on pad-per-hole perfboard and had the regulator cards complete in 30 hours. I got the positive regulator working with a 2N3055 transistor as the NPN series pass device. But when I tried to use the PNP compliment–2N2955 transistor, I could not get it to produce 15V at 7 amps. I finally figured out that the chip, since it uses the Vz pin in the negative configuration, just doesn’t have the same drive capability as it does when using the output pin in the positive configuration.<br />
<br />
The clock was ticking and I was sweating, when I thought of trying a Darlington transistor. I had just purchased some a few days before, so I had them on hand, at midnight with no parts stores open. That proved to be the solution and so I switched the 2N3055 on the positive side for the NPN Darlington compliment of the transistor I had on the negative side. The devices are sold as a complimentary pair at a couple of local electronics stores. This was one of my design objectives, so in case of emergency, the parts are available locally.<br />
<br />
The TO3 packages of the external series pass transistors went into the same holes on the heat-sink as the original regulators. A couple of stand-offs support the cards with the 723s. I connected the regulator inputs to the filter caps and the transistor outputs to the fuses, and the studio was back in business.<br />
<br />
<br />
'''Current Limiting:'''<br />
<br />
The 723 has built in current limiting, but it is designed as a positive regulator. So there is no provision for current limiting in a negative configuration. Also current limiting is dependent on a resistor which must handle the maximum current the regulator is designed to supply. In the case of large currents >1 amp, this produces significant heat. I left the current limiting out of my designs. I didn’t want to have only the positive half of the supply getting limited while the negative half operated with no limit. I reasoned that since the supply outputs were fused, there was already protection in place.<br />
<br />
This is the case with all the regulator designs I present here. If you need current limiting and you just need a positive regulator, the 723 can easily accommodate you. Just figure out how much current you need to supply and how much over that you’re willing to tolerate, then calculate ILimit = Vsense / RSC.<br />
<br />
The regulator is also capable of foldback current limiting where there is a “knee” region before full shutdown occurs. Personally I have never used the current limiting features, so I cannot write from experience. If the supply is to be used in an application where shorting or over currents are possible, I use fuses.<br />
<br />
<br />
'''Low Voltage Supply:'''<br />
<br />
When I began experimenting with embedded processors, I found that many needed supplies in the 3V to 4V range. By this time I had become fairly adept at using the 723 and since I had some still, I decided to use one, rather than investing in a fixed low voltage regulator. Here is the schematic:[[Pos_723_PNP_Reg.jpg]] I went with a positive output using an external PNP transistor. Again, I added a trimmer pot, so I can adjust from around 2.75V to 4.25V. This little board (the transistor has a TO92 package) measures only 1" x 2" and has a power on LED indicator, and two–2-pole screw terminal blocks. It has been very handy.<br />
<br />
<br />
'''“Big Bertha” Bench Supply:'''<br />
<br />
In the world of professional audio, the Jensen 990 discrete opamp is a famous classic. Designed to work with ±24V power supplies, it is considered the “holy grail” of opamp designs. I have worked on MCI’s JH500 series consoles which have ±36V power supply rails–they use a high voltage opamp like the TI OPA544 and add a NPN/PNP output buffer to each. The whole console is filled with these–talk about an air conditioning bill. But having these high voltage rails means the audio signal can reach large levels of voltage swing and go onto the tape as hot as you can stand it. Of course this is analog. With digital there is no need for this. But there are audio people who prefer analog, and a high voltage opamp can add to the sound of the console.<br />
<br />
I have another client who records to digital media, but mixes on an analog console. He had me modify the console master stage with discrete opamps running on their own separate ±24V power supply. He felt that it made the mixes sound better. I can’t say for sure, I was not exposed to listening to it every day, but I have no reason to doubt it. He gets a lot of work coming into his studio.<br />
<br />
But the story here is about “Big Bertha”. I decided I want to design a modern version of the Jensen 990 and I might as well make it able to operate at ±36V. To do this effectively I needed a suitable power supply. I built one using two 36V transformers in series. I regulated it with a pair of 723s and 20A Darlington transistors. Here is the schematic:[[Dual 723 Regulators 7 to 22 V.jpg]] I don’t plan on drawing anywhere near that amount of current, I just had them on hand. In fact everything I used to build “Big Bertha” was residing in drawers and boxes at my shop. (One of the design goals was to make it without spending any money.)<br />
<br />
Actually the unregulated supply is around ±56V. This is beyond the 723's input voltage limit. I could have made floating regulators (more on those later), but I decided to try “amplified zeners” instead. I came across the “amplified zener” in “The Power Supply Handbook” by the editors of 73 magazine. I’ve used it over the years, when I’d get stuck for a solution. It has several clever ideas that have proved very useful, the amplified zener being one of them. Basically you take a zener diode and a transistor and connect them so the zener’s cathode is at the transistor base, and the transistor collector is the zener’s anode. No resistor needed as long as you avoid the knee region of the zener. Here is the schematic: [[Dual Amplified Zeners.jpg]] <br />
I used this trick to knock the unregulated supply down to around ±38V (the 723 max input is 40V). I have these squarish heat sinks that can hold TO3 devices and I stacked 4 of them together; 2 on top of 2, so my amplified zeners and the Darlington pass devices are contained in an area that is the perfect size for a 5" fan, should I ever need to draw so much current that things get warm. So far that hasn’t happened. I can adjust the output from around 12V to just over 30V. I know it isn’t up to the ±36V of the MCI JH500, but I decided that wasn’t really needed. If someone wants an op amp to handle that, I’ll use the OPA544.<br />
<br />
I haven’t really had a chance to put “Big Bertha” to the test. Mostly I’ve used her to power breadboard circuits at around ±18V. This is what Amek and SSL consoles operate at and those are what my remaining clients have. The computer revolution put most of the recording studios in Honolulu out of business.<br />
<br />
Still, I like the idea of having a supply that can give me that kind of voltage range with a rock solid regulation that doesn’t drift or sag.<br />
<br />
<br />
'''Closing Thoughts:'''<br />
<br />
The 723 is a versatile voltage regulator. According to National Semiconductor’s data sheet: “The LM723/LM723C is also useful in a wide range of other applications such as a shunt regulator, a current regulator or a temperature controller.” And “Can be used as either a linear or a switching regulator”.<br />
<br />
I have only used it as a linear series regulator and I’ve been pleased with the results. I have just started experimenting with switching regulators. I built my first one with a TL494 PWM controller. I will probably try out the 723 in that mode of operation when I have some time on my hands and no other projects waiting. But that may be a while, so if anyone has actually done it, I’d appreciate it if you’d share the info.<br />
<br />
I hope this article is useful and I welcome comments and ideas.<br />
<br />
[[User:RogerAF|RAF]] 19:04, 23 May 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=File:Pos_723_PNP_Reg.jpg&diff=4455File:Pos 723 PNP Reg.jpg2007-06-20T06:57:38Z<p>RogerAF: Low Voltage Regulator 2.5V to 4.5V</p>
<hr />
<div>Low Voltage Regulator 2.5V to 4.5V</div>RogerAFhttp://www.opencircuits.com/index.php?title=My_Experience_With_The_723&diff=4454My Experience With The 7232007-06-20T06:55:00Z<p>RogerAF: </p>
<hr />
<div>== My Experience With the 723 Voltage Regulator IC ==<br />
<br />
'''Introduction:'''<br />
<br />
I came across [[The 723 Voltage Regulator]] in the 1980s and thought it was much too complicated to use. I liked the 3-terminal regulators and stayed with them until I had to make a power supply that would handle more current than they could supply. In the mid ‘80s I’d come across a copy of an article called “The Many Talented 723" by Glen Prescott. I don’t know where this was published and I’ve been unable to locate it through Google. However I still have my copy and I decided it was worth scanning and cleaning up the figures, so I can share it with the world.<br />
<br />
There are a couple of companies who make the device, that describe it in their data sheet titles as a “Precision Voltage Regulator”. This is what it is. If you were to design a voltage regulator from scratch, using discrete components. You’d want to end up with something like the 723. I’m not going to go into detail about it, because the data sheets and Mr. Prescott’s article do that very well already. I just want to share some of my experiences in the use of it.<br />
<br />
<br />
'''My First Mixer Power Supply:'''<br />
<br />
I built a little microphone mixer while I was in electronics school and I needed a power supply for it. I had a pair of LM723 ICs in a drawer, but I’d never worked with the chip. I decided that I should learn about it. The National Semiconductor Linear data book showed a lot of different ways to use it and decided to build a plus and minus 15 volt supply with external pass devices. I included trimmers for fine tuning the outputs and I had a little aluminum case that I could fit the transformer, rectifier, filter capacitors, and PC board into. I used a sharpie pen and drew the layout by hand except for the IC patterns. I etched the board and assembled it. It powered my mixer very nicely and I got an A in that class.<br />
<br />
Last year I started experimenting with an Analog Devices AD7329–a 13-bit, 8 channel A to D converter which requires ±15V as well as 5V supplies. I dusted my little power supply off (it is over 20 years old now) tuned it on and checked the outputs. I thought I’d probably need to adjust the trimmers some, but even after sitting for the last 20 years, it was measuring +14.998V and -15.01V. I was very impressed and decided it was too nice to leave in a box. So it is out of retirement and I use it for my experiments on my bench whenever I’m working with op-amps that need ±15V.<br />
<br />
<br />
'''Second Mixer Power Supply:'''<br />
<br />
I service several recording studios here in Honolulu. One of my clients has a console whose power supply failed. It had failed before and I’d replaced the regulators, which were high current (7 amps) devices in TO3 packages. But the last time it failed I could not find replacements. I’ve forgotten the part number of the device, but it does not seem to be made any more and no one has produced a substitute.<br />
<br />
My client was understandably upset. Recording studios need to have working equipment–especially the mixing console. I told him I’d need at least 48 hours if not 72 to build replacement regulators. He said to hurry.<br />
<br />
I used the same circuit as in my little mixer supply above. I hand wired it on pad-per-hole perfboard and had the regulator cards complete in 30 hours. I got the positive regulator working with a 2N3055 transistor as the NPN series pass device. But when I tried to use the PNP compliment–2N2955 transistor, I could not get it to produce 15V at 7 amps. I finally figured out that the chip, since it uses the Vz pin in the negative configuration, just doesn’t have the same drive capability as it does when using the output pin in the positive configuration.<br />
<br />
The clock was ticking and I was sweating, when I thought of trying a Darlington transistor. I had just purchased some a few days before, so I had them on hand, at midnight with no parts stores open. That proved to be the solution and so I switched the 2N3055 on the positive side for the NPN Darlington compliment of the transistor I had on the negative side. The devices are sold as a complimentary pair at a couple of local electronics stores. This was one of my design objectives, so in case of emergency, the parts are available locally.<br />
<br />
The TO3 packages of the external series pass transistors went into the same holes on the heat-sink as the original regulators. A couple of stand-offs support the cards with the 723s. I connected the regulator inputs to the filter caps and the transistor outputs to the fuses, and the studio was back in business.<br />
<br />
<br />
'''Current Limiting:'''<br />
<br />
The 723 has built in current limiting, but it is designed as a positive regulator. So there is no provision for current limiting in a negative configuration. Also current limiting is dependent on a resistor which must handle the maximum current the regulator is designed to supply. In the case of large currents >1 amp, this produces significant heat. I left the current limiting out of my designs. I didn’t want to have only the positive half of the supply getting limited while the negative half operated with no limit. I reasoned that since the supply outputs were fused, there was already protection in place.<br />
<br />
This is the case with all the regulator designs I present here. If you need current limiting and you just need a positive regulator, the 723 can easily accommodate you. Just figure out how much current you need to supply and how much over that you’re willing to tolerate, then calculate ILimit = Vsense / RSC.<br />
<br />
The regulator is also capable of foldback current limiting where there is a “knee” region before full shutdown occurs. Personally I have never used the current limiting features, so I cannot write from experience. If the supply is to be used in an application where shorting or over currents are possible, I use fuses.<br />
<br />
<br />
'''Low Voltage Supply:'''<br />
<br />
When I began experimenting with embedded processors, I found that many needed supplies in the 3V to 4V range. By this time I had become fairly adept at using the 723 and since I had some still, I decided to use one, rather than investing in a fixed low voltage regulator. I went with a positive output using an external PNP transistor. Again, I added a trimmer pot, so I can adjust from around 2.75V to 4.25V. This little board (the transistor has a TO92 package) measures only 1" x 2" and has a power on LED indicator, and two–2-pole screw terminal blocks. It has been very handy.<br />
<br />
<br />
'''“Big Bertha” Bench Supply:'''<br />
<br />
In the world of professional audio, the Jensen 990 discrete opamp is a famous classic. Designed to work with ±24V power supplies, it is considered the “holy grail” of opamp designs. I have worked on MCI’s JH500 series consoles which have ±36V power supply rails–they use a high voltage opamp like the TI OPA544 and add a NPN/PNP output buffer to each. The whole console is filled with these–talk about an air conditioning bill. But having these high voltage rails means the audio signal can reach large levels of voltage swing and go onto the tape as hot as you can stand it. Of course this is analog. With digital there is no need for this. But there are audio people who prefer analog, and a high voltage opamp can add to the sound of the console.<br />
<br />
I have another client who records to digital media, but mixes on an analog console. He had me modify the console master stage with discrete opamps running on their own separate ±24V power supply. He felt that it made the mixes sound better. I can’t say for sure, I was not exposed to listening to it every day, but I have no reason to doubt it. He gets a lot of work coming into his studio.<br />
<br />
But the story here is about “Big Bertha”. I decided I want to design a modern version of the Jensen 990 and I might as well make it able to operate at ±36V. To do this effectively I needed a suitable power supply. I built one using two 36V transformers in series. I regulated it with a pair of 723s and 20A Darlington transistors. Here is the schematic:[[Dual 723 Regulators 7 to 22 V.jpg]] I don’t plan on drawing anywhere near that amount of current, I just had them on hand. In fact everything I used to build “Big Bertha” was residing in drawers and boxes at my shop. (One of the design goals was to make it without spending any money.)<br />
<br />
Actually the unregulated supply is around ±56V. This is beyond the 723's input voltage limit. I could have made floating regulators (more on those later), but I decided to try “amplified zeners” instead. I came across the “amplified zener” in “The Power Supply Handbook” by the editors of 73 magazine. I’ve used it over the years, when I’d get stuck for a solution. It has several clever ideas that have proved very useful, the amplified zener being one of them. Basically you take a zener diode and a transistor and connect them so the zener’s cathode is at the transistor base, and the transistor collector is the zener’s anode. No resistor needed as long as you avoid the knee region of the zener. Here is the schematic: [[Dual Amplified Zeners.jpg]] <br />
I used this trick to knock the unregulated supply down to around ±38V (the 723 max input is 40V). I have these squarish heat sinks that can hold TO3 devices and I stacked 4 of them together; 2 on top of 2, so my amplified zeners and the Darlington pass devices are contained in an area that is the perfect size for a 5" fan, should I ever need to draw so much current that things get warm. So far that hasn’t happened. I can adjust the output from around 12V to just over 30V. I know it isn’t up to the ±36V of the MCI JH500, but I decided that wasn’t really needed. If someone wants an op amp to handle that, I’ll use the OPA544.<br />
<br />
I haven’t really had a chance to put “Big Bertha” to the test. Mostly I’ve used her to power breadboard circuits at around ±18V. This is what Amek and SSL consoles operate at and those are what my remaining clients have. The computer revolution put most of the recording studios in Honolulu out of business.<br />
<br />
Still, I like the idea of having a supply that can give me that kind of voltage range with a rock solid regulation that doesn’t drift or sag.<br />
<br />
<br />
'''Closing Thoughts:'''<br />
<br />
The 723 is a versatile voltage regulator. According to National Semiconductor’s data sheet: “The LM723/LM723C is also useful in a wide range of other applications such as a shunt regulator, a current regulator or a temperature controller.” And “Can be used as either a linear or a switching regulator”.<br />
<br />
I have only used it as a linear series regulator and I’ve been pleased with the results. I have just started experimenting with switching regulators. I built my first one with a TL494 PWM controller. I will probably try out the 723 in that mode of operation when I have some time on my hands and no other projects waiting. But that may be a while, so if anyone has actually done it, I’d appreciate it if you’d share the info.<br />
<br />
I hope this article is useful and I welcome comments and ideas.<br />
<br />
[[User:RogerAF|RAF]] 19:04, 23 May 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=Dual_723_Regulators_7_to_22_V.jpg&diff=4453Dual 723 Regulators 7 to 22 V.jpg2007-06-20T06:53:50Z<p>RogerAF: "Big Bertha" Dual 723 Regulators Adjustable +&- 12V to 30V</p>
<hr />
<div>Back to: [[My Experience With The 723]]<br />
[[Image:Dual 723 Regulators 7 to 22 V.jpg]]</div>RogerAFhttp://www.opencircuits.com/index.php?title=My_Experience_With_The_723&diff=4452My Experience With The 7232007-06-20T06:49:45Z<p>RogerAF: </p>
<hr />
<div>== My Experience With the 723 Voltage Regulator IC ==<br />
<br />
'''Introduction:'''<br />
<br />
I came across [[The 723 Voltage Regulator]] in the 1980s and thought it was much too complicated to use. I liked the 3-terminal regulators and stayed with them until I had to make a power supply that would handle more current than they could supply. In the mid ‘80s I’d come across a copy of an article called “The Many Talented 723" by Glen Prescott. I don’t know where this was published and I’ve been unable to locate it through Google. However I still have my copy and I decided it was worth scanning and cleaning up the figures, so I can share it with the world.<br />
<br />
There are a couple of companies who make the device, that describe it in their data sheet titles as a “Precision Voltage Regulator”. This is what it is. If you were to design a voltage regulator from scratch, using discrete components. You’d want to end up with something like the 723. I’m not going to go into detail about it, because the data sheets and Mr. Prescott’s article do that very well already. I just want to share some of my experiences in the use of it.<br />
<br />
<br />
'''My First Mixer Power Supply:'''<br />
<br />
I built a little microphone mixer while I was in electronics school and I needed a power supply for it. I had a pair of LM723 ICs in a drawer, but I’d never worked with the chip. I decided that I should learn about it. The National Semiconductor Linear data book showed a lot of different ways to use it and decided to build a plus and minus 15 volt supply with external pass devices. I included trimmers for fine tuning the outputs and I had a little aluminum case that I could fit the transformer, rectifier, filter capacitors, and PC board into. I used a sharpie pen and drew the layout by hand except for the IC patterns. I etched the board and assembled it. It powered my mixer very nicely and I got an A in that class.<br />
<br />
Last year I started experimenting with an Analog Devices AD7329–a 13-bit, 8 channel A to D converter which requires ±15V as well as 5V supplies. I dusted my little power supply off (it is over 20 years old now) tuned it on and checked the outputs. I thought I’d probably need to adjust the trimmers some, but even after sitting for the last 20 years, it was measuring +14.998V and -15.01V. I was very impressed and decided it was too nice to leave in a box. So it is out of retirement and I use it for my experiments on my bench whenever I’m working with op-amps that need ±15V.<br />
<br />
<br />
'''Second Mixer Power Supply:'''<br />
<br />
I service several recording studios here in Honolulu. One of my clients has a console whose power supply failed. It had failed before and I’d replaced the regulators, which were high current (7 amps) devices in TO3 packages. But the last time it failed I could not find replacements. I’ve forgotten the part number of the device, but it does not seem to be made any more and no one has produced a substitute.<br />
<br />
My client was understandably upset. Recording studios need to have working equipment–especially the mixing console. I told him I’d need at least 48 hours if not 72 to build replacement regulators. He said to hurry.<br />
<br />
I used the same circuit as in my little mixer supply above. I hand wired it on pad-per-hole perfboard and had the regulator cards complete in 30 hours. I got the positive regulator working with a 2N3055 transistor as the NPN series pass device. But when I tried to use the PNP compliment–2N2955 transistor, I could not get it to produce 15V at 7 amps. I finally figured out that the chip, since it uses the Vz pin in the negative configuration, just doesn’t have the same drive capability as it does when using the output pin in the positive configuration.<br />
<br />
The clock was ticking and I was sweating, when I thought of trying a Darlington transistor. I had just purchased some a few days before, so I had them on hand, at midnight with no parts stores open. That proved to be the solution and so I switched the 2N3055 on the positive side for the NPN Darlington compliment of the transistor I had on the negative side. The devices are sold as a complimentary pair at a couple of local electronics stores. This was one of my design objectives, so in case of emergency, the parts are available locally.<br />
<br />
The TO3 packages of the external series pass transistors went into the same holes on the heat-sink as the original regulators. A couple of stand-offs support the cards with the 723s. I connected the regulator inputs to the filter caps and the transistor outputs to the fuses, and the studio was back in business.<br />
<br />
<br />
'''Current Limiting:'''<br />
<br />
The 723 has built in current limiting, but it is designed as a positive regulator. So there is no provision for current limiting in a negative configuration. Also current limiting is dependent on a resistor which must handle the maximum current the regulator is designed to supply. In the case of large currents >1 amp, this produces significant heat. I left the current limiting out of my designs. I didn’t want to have only the positive half of the supply getting limited while the negative half operated with no limit. I reasoned that since the supply outputs were fused, there was already protection in place.<br />
<br />
This is the case with all the regulator designs I present here. If you need current limiting and you just need a positive regulator, the 723 can easily accommodate you. Just figure out how much current you need to supply and how much over that you’re willing to tolerate, then calculate ILimit = Vsense / RSC.<br />
<br />
The regulator is also capable of foldback current limiting where there is a “knee” region before full shutdown occurs. Personally I have never used the current limiting features, so I cannot write from experience. If the supply is to be used in an application where shorting or over currents are possible, I use fuses.<br />
<br />
<br />
'''Low Voltage Supply:'''<br />
<br />
When I began experimenting with embedded processors, I found that many needed supplies in the 3V to 4V range. By this time I had become fairly adept at using the 723 and since I had some still, I decided to use one, rather than investing in a fixed low voltage regulator. I went with a positive output using an external PNP transistor. Again, I added a trimmer pot, so I can adjust from around 2.75V to 4.25V. This little board (the transistor has a TO92 package) measures only 1" x 2" and has a power on LED indicator, and two–2-pole screw terminal blocks. It has been very handy.<br />
<br />
<br />
'''“Big Bertha” Bench Supply:'''<br />
<br />
In the world of professional audio, the Jensen 990 discrete opamp is a famous classic. Designed to work with ±24V power supplies, it is considered the “holy grail” of opamp designs. I have worked on MCI’s JH500 series consoles which have ±36V power supply rails–they use a high voltage opamp like the TI OPA544 and add a NPN/PNP output buffer to each. The whole console is filled with these–talk about an air conditioning bill. But having these high voltage rails means the audio signal can reach large levels of voltage swing and go onto the tape as hot as you can stand it. Of course this is analog. With digital there is no need for this. But there are audio people who prefer analog, and a high voltage opamp can add to the sound of the console.<br />
<br />
I have another client who records to digital media, but mixes on an analog console. He had me modify the console master stage with discrete opamps running on their own separate ±24V power supply. He felt that it made the mixes sound better. I can’t say for sure, I was not exposed to listening to it every day, but I have no reason to doubt it. He gets a lot of work coming into his studio.<br />
<br />
But the story here is about “Big Bertha”. I decided I want to design a modern version of the Jensen 990 and I might as well make it able to operate at ±36V. To do this effectively I needed a suitable power supply. I built one using two 36V transformers in series. I regulated it with a pair of 723s and 20A Darlington transistors. I don’t plan on drawing anywhere near that amount of current, I just had them on hand. In fact everything I used to build “Big Bertha” was residing in drawers and boxes at my shop. (One of the design goals was to make it without spending any money.)<br />
<br />
Actually the unregulated supply is around ±56V. This is beyond the 723's input voltage limit. I could have made floating regulators (more on those later), but I decided to try “amplified zeners” instead. I came across the “amplified zener” in “The Power Supply Handbook” by the editors of 73 magazine. I’ve used it over the years, when I’d get stuck for a solution. It has several clever ideas that have proved very useful, the amplified zener being one of them. Basically you take a zener diode and a transistor and connect them so the zener’s cathode is at the transistor base, and the transistor collector is the zener’s anode. No resistor needed as long as you avoid the knee region of the zener. Here is the schematic: [[Dual Amplified Zeners.jpg]] <br />
I used this trick to knock the unregulated supply down to around ±38V (the 723 max input is 40V). I have these squarish heat sinks that can hold TO3 devices and I stacked 4 of them together; 2 on top of 2, so my amplified zeners and the Darlington pass devices are contained in an area that is the perfect size for a 5" fan, should I ever need to draw so much current that things get warm. So far that hasn’t happened. I can adjust the output from around 12V to just over 30V. I know it isn’t up to the ±36V of the MCI JH500, but I decided that wasn’t really needed. If someone wants an op amp to handle that, I’ll use the OPA544.<br />
<br />
I haven’t really had a chance to put “Big Bertha” to the test. Mostly I’ve used her to power breadboard circuits at around ±18V. This is what Amek and SSL consoles operate at and those are what my remaining clients have. The computer revolution put most of the recording studios in Honolulu out of business.<br />
<br />
Still, I like the idea of having a supply that can give me that kind of voltage range with a rock solid regulation that doesn’t drift or sag.<br />
<br />
<br />
'''Closing Thoughts:'''<br />
<br />
The 723 is a versatile voltage regulator. According to National Semiconductor’s data sheet: “The LM723/LM723C is also useful in a wide range of other applications such as a shunt regulator, a current regulator or a temperature controller.” And “Can be used as either a linear or a switching regulator”.<br />
<br />
I have only used it as a linear series regulator and I’ve been pleased with the results. I have just started experimenting with switching regulators. I built my first one with a TL494 PWM controller. I will probably try out the 723 in that mode of operation when I have some time on my hands and no other projects waiting. But that may be a while, so if anyone has actually done it, I’d appreciate it if you’d share the info.<br />
<br />
I hope this article is useful and I welcome comments and ideas.<br />
<br />
[[User:RogerAF|RAF]] 19:04, 23 May 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=Dual_Amplified_Zeners.jpg&diff=4451Dual Amplified Zeners.jpg2007-06-20T06:48:19Z<p>RogerAF: </p>
<hr />
<div>Back to:[[My Experience With The 723]]<br />
[[Image:Dual Amplified Zeners.jpg]]</div>RogerAFhttp://www.opencircuits.com/index.php?title=My_Experience_With_The_723&diff=4450My Experience With The 7232007-06-20T06:46:53Z<p>RogerAF: </p>
<hr />
<div>== My Experience With the 723 Voltage Regulator IC ==<br />
<br />
'''Introduction:'''<br />
<br />
I came across [[The 723 Voltage Regulator]] in the 1980s and thought it was much too complicated to use. I liked the 3-terminal regulators and stayed with them until I had to make a power supply that would handle more current than they could supply. In the mid ‘80s I’d come across a copy of an article called “The Many Talented 723" by Glen Prescott. I don’t know where this was published and I’ve been unable to locate it through Google. However I still have my copy and I decided it was worth scanning and cleaning up the figures, so I can share it with the world.<br />
<br />
There are a couple of companies who make the device, that describe it in their data sheet titles as a “Precision Voltage Regulator”. This is what it is. If you were to design a voltage regulator from scratch, using discrete components. You’d want to end up with something like the 723. I’m not going to go into detail about it, because the data sheets and Mr. Prescott’s article do that very well already. I just want to share some of my experiences in the use of it.<br />
<br />
<br />
'''My First Mixer Power Supply:'''<br />
<br />
I built a little microphone mixer while I was in electronics school and I needed a power supply for it. I had a pair of LM723 ICs in a drawer, but I’d never worked with the chip. I decided that I should learn about it. The National Semiconductor Linear data book showed a lot of different ways to use it and decided to build a plus and minus 15 volt supply with external pass devices. I included trimmers for fine tuning the outputs and I had a little aluminum case that I could fit the transformer, rectifier, filter capacitors, and PC board into. I used a sharpie pen and drew the layout by hand except for the IC patterns. I etched the board and assembled it. It powered my mixer very nicely and I got an A in that class.<br />
<br />
Last year I started experimenting with an Analog Devices AD7329–a 13-bit, 8 channel A to D converter which requires ±15V as well as 5V supplies. I dusted my little power supply off (it is over 20 years old now) tuned it on and checked the outputs. I thought I’d probably need to adjust the trimmers some, but even after sitting for the last 20 years, it was measuring +14.998V and -15.01V. I was very impressed and decided it was too nice to leave in a box. So it is out of retirement and I use it for my experiments on my bench whenever I’m working with op-amps that need ±15V.<br />
<br />
<br />
'''Second Mixer Power Supply:'''<br />
<br />
I service several recording studios here in Honolulu. One of my clients has a console whose power supply failed. It had failed before and I’d replaced the regulators, which were high current (7 amps) devices in TO3 packages. But the last time it failed I could not find replacements. I’ve forgotten the part number of the device, but it does not seem to be made any more and no one has produced a substitute.<br />
<br />
My client was understandably upset. Recording studios need to have working equipment–especially the mixing console. I told him I’d need at least 48 hours if not 72 to build replacement regulators. He said to hurry.<br />
<br />
I used the same circuit as in my little mixer supply above. I hand wired it on pad-per-hole perfboard and had the regulator cards complete in 30 hours. I got the positive regulator working with a 2N3055 transistor as the NPN series pass device. But when I tried to use the PNP compliment–2N2955 transistor, I could not get it to produce 15V at 7 amps. I finally figured out that the chip, since it uses the Vz pin in the negative configuration, just doesn’t have the same drive capability as it does when using the output pin in the positive configuration.<br />
<br />
The clock was ticking and I was sweating, when I thought of trying a Darlington transistor. I had just purchased some a few days before, so I had them on hand, at midnight with no parts stores open. That proved to be the solution and so I switched the 2N3055 on the positive side for the NPN Darlington compliment of the transistor I had on the negative side. The devices are sold as a complimentary pair at a couple of local electronics stores. This was one of my design objectives, so in case of emergency, the parts are available locally.<br />
<br />
The TO3 packages of the external series pass transistors went into the same holes on the heat-sink as the original regulators. A couple of stand-offs support the cards with the 723s. I connected the regulator inputs to the filter caps and the transistor outputs to the fuses, and the studio was back in business.<br />
<br />
<br />
'''Current Limiting:'''<br />
<br />
The 723 has built in current limiting, but it is designed as a positive regulator. So there is no provision for current limiting in a negative configuration. Also current limiting is dependent on a resistor which must handle the maximum current the regulator is designed to supply. In the case of large currents >1 amp, this produces significant heat. I left the current limiting out of my designs. I didn’t want to have only the positive half of the supply getting limited while the negative half operated with no limit. I reasoned that since the supply outputs were fused, there was already protection in place.<br />
<br />
This is the case with all the regulator designs I present here. If you need current limiting and you just need a positive regulator, the 723 can easily accommodate you. Just figure out how much current you need to supply and how much over that you’re willing to tolerate, then calculate ILimit = Vsense / RSC.<br />
<br />
The regulator is also capable of foldback current limiting where there is a “knee” region before full shutdown occurs. Personally I have never used the current limiting features, so I cannot write from experience. If the supply is to be used in an application where shorting or over currents are possible, I use fuses.<br />
<br />
<br />
'''Low Voltage Supply:'''<br />
<br />
When I began experimenting with embedded processors, I found that many needed supplies in the 3V to 4V range. By this time I had become fairly adept at using the 723 and since I had some still, I decided to use one, rather than investing in a fixed low voltage regulator. I went with a positive output using an external PNP transistor. Again, I added a trimmer pot, so I can adjust from around 2.75V to 4.25V. This little board (the transistor has a TO92 package) measures only 1" x 2" and has a power on LED indicator, and two–2-pole screw terminal blocks. It has been very handy.<br />
<br />
<br />
'''“Big Bertha” Bench Supply:'''<br />
<br />
In the world of professional audio, the Jensen 990 discrete opamp is a famous classic. Designed to work with ±24V power supplies, it is considered the “holy grail” of opamp designs. I have worked on MCI’s JH500 series consoles which have ±36V power supply rails–they use a high voltage opamp like the TI OPA544 and add a NPN/PNP output buffer to each. The whole console is filled with these–talk about an air conditioning bill. But having these high voltage rails means the audio signal can reach large levels of voltage swing and go onto the tape as hot as you can stand it. Of course this is analog. With digital there is no need for this. But there are audio people who prefer analog, and a high voltage opamp can add to the sound of the console.<br />
<br />
I have another client who records to digital media, but mixes on an analog console. He had me modify the console master stage with discrete opamps running on their own separate ±24V power supply. He felt that it made the mixes sound better. I can’t say for sure, I was not exposed to listening to it every day, but I have no reason to doubt it. He gets a lot of work coming into his studio.<br />
<br />
But the story here is about “Big Bertha”. I decided I want to design a modern version of the Jensen 990 and I might as well make it able to operate at ±36V. To do this effectively I needed a suitable power supply. I built one using two 36V transformers in series. I regulated it with a pair of 723s and 20A Darlington transistors. I don’t plan on drawing anywhere near that amount of current, I just had them on hand. In fact everything I used to build “Big Bertha” was residing in drawers and boxes at my shop. (One of the design goals was to make it without spending any money.)<br />
<br />
Actually the unregulated supply is around ±56V. This is beyond the 723's input voltage limit. I could have made floating regulators (more on those later), but I decided to try “amplified zeners” instead. I came across the “amplified zener” in “The Power Supply Handbook” by the editors of 73 magazine. I’ve used it over the years, when I’d get stuck for a solution. It has several clever ideas that have proved very useful, the amplified zener being one of them. Basically you take a zener diode and a transistor and connect them so the zener’s cathode is at the transistor base, and the transistor collector is the zener’s anode. No resistor needed as long as you avoid the knee region of the zener.[[Dual Amplified Zeners.jpg]] I used this trick to knock the unregulated supply down to around ±38V (the 723 max input is 40V). I have these squarish heat sinks that can hold TO3 devices and I stacked 4 of them together; 2 on top of 2, so my amplified zeners and the Darlington pass devices are contained in an area that is the perfect size for a 5" fan, should I ever need to draw so much current that things get warm. So far that hasn’t happened. I can adjust the output from around 12V to just over 30V. I know it isn’t up to the ±36V of the MCI JH500, but I decided that wasn’t really needed. If someone wants an op amp to handle that, I’ll use the OPA544.<br />
<br />
I haven’t really had a chance to put “Big Bertha” to the test. Mostly I’ve used her to power breadboard circuits at around ±18V. This is what Amek and SSL consoles operate at and those are what my remaining clients have. The computer revolution put most of the recording studios in Honolulu out of business.<br />
<br />
Still, I like the idea of having a supply that can give me that kind of voltage range with a rock solid regulation that doesn’t drift or sag.<br />
<br />
<br />
'''Closing Thoughts:'''<br />
<br />
The 723 is a versatile voltage regulator. According to National Semiconductor’s data sheet: “The LM723/LM723C is also useful in a wide range of other applications such as a shunt regulator, a current regulator or a temperature controller.” And “Can be used as either a linear or a switching regulator”.<br />
<br />
I have only used it as a linear series regulator and I’ve been pleased with the results. I have just started experimenting with switching regulators. I built my first one with a TL494 PWM controller. I will probably try out the 723 in that mode of operation when I have some time on my hands and no other projects waiting. But that may be a while, so if anyone has actually done it, I’d appreciate it if you’d share the info.<br />
<br />
I hope this article is useful and I welcome comments and ideas.<br />
<br />
[[User:RogerAF|RAF]] 19:04, 23 May 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=Dual_Amplified_Zeners.jpg&diff=4449Dual Amplified Zeners.jpg2007-06-20T06:45:31Z<p>RogerAF: Dual Amplified Zeners Schematic</p>
<hr />
<div>[[Image:Dual Amplified Zeners.jpg]]</div>RogerAFhttp://www.opencircuits.com/index.php?title=File:Dual_723_Regulators_7_to_22_V.jpg&diff=4448File:Dual 723 Regulators 7 to 22 V.jpg2007-06-20T06:34:56Z<p>RogerAF: "Big Bertha" dual +&- adjustable regulators</p>
<hr />
<div>"Big Bertha" dual +&- adjustable regulators</div>RogerAFhttp://www.opencircuits.com/index.php?title=File:Dual_Amplified_Zeners.jpg&diff=4447File:Dual Amplified Zeners.jpg2007-06-20T06:33:13Z<p>RogerAF: Front end for "Big Bertha" power supply</p>
<hr />
<div>Front end for "Big Bertha" power supply</div>RogerAFhttp://www.opencircuits.com/index.php?title=The_723_Voltage_Regulator&diff=4446The 723 Voltage Regulator2007-06-20T05:59:16Z<p>RogerAF: /* The 723 Voltage Regulator */</p>
<hr />
<div>== The 723 Voltage Regulator ==<br />
[[Image:UA723CN_Symbol.gif]]<br />
<br />
'''Description:'''<br />
<br />
The 723 is ancient in the world of IC voltage regulators. It is a 14-pin IC that needs some outboard components to tell it what to do. By itself it isn’t that impressive with a current capacity of 150mA, but with the addition of an external series pass transistor it can control whatever current the transistor can handle. It is designed primarily to be used as a positive regulator, but it can also be made to function as a negative regulator. In addition, although it is rated to 37 volts, it can be used in a “floating” mode and regulate voltages above that limit. All in all, I’ve found it to be a very stable, precise, and versatile device.<br />
<br />
The main IC: LM723 is specified at temperatures from -55°C to +125°C. This chip is a little harder to find, and is more expensive than the LM723C which is exactly the same (as far as I know) but for the temperature spec which is from 0°C to +70°C.<br />
<br />
The document: “The Many Talented 723" by Glen Prescott was my introduction to using the 723. I have been unable to find out anything about the author or where the article was published. Therefore obtaining permission to publish it has been impossible. If anyone reading this has any knowledge of the document, please leave a word here and let me know, so I can attempt to get permission to publish it here.<br />
<br />
“[[My Experience With The 723]]” by Roger Furer is my own story of the different regulator circuits I’ve built with it and includes links to schematics and PC Board layouts. (Coming Soon)<br />
<br />
'''Documents:'''<br />
<br />
Several companies manufacture the LM723, but the data sheets are pretty much the same.<br />
<br />
Texas Instruments calls it the µA723:<br />
[http://focus.ti.com/lit/ds/symlink/ua723.pdf]<br />
<br />
National Semiconductor calls it the LM723 and LM723C (reduced temperature version)<br />
[http://cache.national.com/ds/LM/LM723.pdf]<br />
<br />
On Semiconductor never heard of it, but ST Microelectronics makes the LM723 (with various suffixes)<br />
[http://www.st.com/stonline/products/literature/ds/4553/lm723.pdf]<br />
<br />
'''Footprints:'''<br />
<br />
It is available as a 14-pin DIP from everyone. In a metal can: H10C from National, and as an SO-14 from STM and TI. There may be other packages available from other manufacturers, but I limited my search to these three. Note that only the DIP-14 package has the Vz pin--the output from the zener diode which is used for negative regulators. The metal can and the flat-pack do not have enough pins and so they skip this one.<br />
<br />
'''Manufacturer Info:'''<br />
<br />
'''Note: '''<br />
The LM723C is identical to the LM723 except that the LM723C has its performance guaranteed over a 0̊C to +70̊C temperature range, instead of −55̊C to +125̊C.<br />
<br />
<br />
National Semiconductor part # :<br />
<br />
LM723H, LM723H/883, or LM723CH : Metal Can Package (H), NS Package H10C<br />
<br />
LM723J/883 : Ceramic Dual-In-Line Package (J), NS Package J14A<br />
<br />
LM723CN : Molded Dual-In-Line Package (N), NS Package N14A<br />
<br />
<br />
ST Microelectronics part # :<br />
<br />
LM723N : DIP-14<br />
<br />
LM723CN : DIP-14<br />
<br />
LM723CD : SO-14<br />
<br />
<br />
Texas Instruments part # :<br />
<br />
µA723CN : Plastic DIP (N),<br />
<br />
µA723CD : Small Outline (D)<br />
<br />
<br />
NTE makes a substitute: NTE923<br />
<br />
'''Supplier Info:'''<br />
<br />
'''Jameco'''<br />
<br />
Major Brands<br />
<br />
LM723CN, DIP-14, Jameco part# : 24467, price: 1+ 0.34<br />
<br />
LM723H, TO-5, Jameco part# : 301719, price: 1+ 3.69<br />
<br />
Texas Instruments<br />
<br />
UA723CDE4 Jameco part# : 1129851, price: 50+ 0.319<br />
<br />
UA723CNE4 Jameco part# : 1129914, price: 1000+ 0.295<br />
<br />
<br />
National Semiconductor<br />
<br />
LM723CN/NOPB Jameco part# : 840691, price: 10+ 0.482<br />
<br />
<br />
<br />
'''Mouser'''<br />
<br />
Fairchild Semiconductor<br />
<br />
KA723, DIP-14 Mouser part# : 512-KA723, price: 1+ .67<br />
<br />
KA723DTF, SOP-14 Mouser part# : 512-KA723DTF, price: 1+ .67<br />
<br />
<br />
ST Microelectronics<br />
<br />
LM723CD, SO-14 Mouser part# : 511-LM723CD, price: 1+ .38<br />
<br />
LM723CN, DIP-14 Mouser part# : 511-LM723CN, price: 1+ .32<br />
<br />
LM723N, DIP-14 Mouser part# : 511-LM723N, price: 1+ .64<br />
<br />
Texas Instruments<br />
UA723CN, DIP-14 Mouser part# : 595-UA723CN, price: 1+ .53<br />
<br />
<br />
'''Digikey'''<br />
<br />
National Semiconductor<br />
<br />
LM723CH/NOPB, TO-5 Digikey part # : LM723CH-ND, price: 1+ 5.48<br />
<br />
LM723H, TO-5 Digikey part # : LM723H-ND, price: 1+ 5.48<br />
<br />
LM723CN/NOPB, DIP-14 Digikey part # : LM723CNNS-ND, price: 1+ 1.12<br />
<br />
<br />
ST Microelectronics<br />
<br />
LM723N, DIP-14 Digikey part # : 497-4268-5-ND, price: 1+ 0.99<br />
<br />
LM723CD, 14-SOIC Digikey part # : 497-1595-5-ND, price: 1+ 0.86<br />
<br />
<br />
there are more, but you get the idea.</div>RogerAFhttp://www.opencircuits.com/index.php?title=POV_display&diff=4157POV display2007-06-09T21:13:25Z<p>RogerAF: /* POV display */</p>
<hr />
<div>== POV display ==<br />
<br />
[[User:DavidCary]] is building yet another "POV display".<br />
<br />
I plan on putting a few features into my display that I haven't seen in any other so far:<br />
<br />
* bright blue LEDs (even though blue is usually the most expensive color ... although sometimes "true green" is even more expensive than blue).<br />
* no slip rings -- just pumping energy across an air gap<br />
* ... and a few other features that I'm keeping hush-hush.<br />
<br />
I want lots of lumens.<br />
Unfortunately, when I go to pick LEDs out of the catalogs, they're not<br />
rated in lumens, they're rated in candelas.<br />
<br />
Is it even possible to estimate "lumens" from the catalog information?<br />
<br />
Do you know what the difference is? Does your flashlight really<br />
produce 10 times the light ( in lumens)? Or does the flashlight merely<br />
focus its light on a tiny spot, so that that spot gets 10 times as<br />
many candelas ?<br />
<br />
For example, check out these 2 LEDs:<br />
$8.75 SSP-LX6144C7UC : 4000 mcd at 120 mA<br />
$8.75 SSP-LX6144D7UC : 1800 mcd at 120 mA<br />
<br />
From the mcd rating, it appears that the first one is more than 2wice<br />
as bright -- and it is, if you're directly in front of it when you<br />
look at it.<br />
However, if you're even the tiniest bit off-center, the second one is<br />
much brighter -- in fact, the total lumens that second LED puts out<br />
(2500 mlm) is slightly more than the total lumens than the first one.<br />
If you diffuse the light and try to light up a whole room with an<br />
array of them, the second one will make the room brighter.<br />
<br />
I'm currently planning on using these in my first POV display:<br />
* $1.32 Telux TLWB7900 : blue : 330 mlm, 231 mcd at 50 mA. (price in ones from http://Newark.com/ )<br />
<br />
Other LEDs I considered using in my POV display (and may re-consider for my next one):<br />
<br />
* $18.89 "Lamina light engine" BL-22B1-0140 : 22000 mlm at 420 mA. (this price includes the required heat sink -- price in ones from http://Digikey.com/ ). This has the most lumens per dollar I've found so far (for blue LEDs).<br />
* $8.750 Sunbrite LuxLEDs SSP-LX6144D7UC blue: 120 mA, 2500 mlm, 1800 mcd (Odd that the red Sunbrite LuxLEDs are cheaper at Newark, the other colors cheaper at Digikey.) cheapest $/lumen blue LED, except for the "light engine"<br />
* $2.550 Lumex "DSP LED" 67-1876-ND: blue, 5 mm, 2500 mcd ( DigiKey ) apparently have some kind of internal chip. All colors run at 2.0 V nominal (1.5 V minimum) (rather than running on current like most LEDs. unfortunately, the data sheet doesn't suggest how much current they take -- I presume more than 20 mA).<br />
* $1.600 Sunbrite "based LED" SSP-01TWB7UWB12 (441-1007-ND) blue 10 mm 20 mA 7000 mcd<br />
* $5.980 GM5WA06270A SMT RGB (35 mA red, 35 mA green, 35 mA blue) 3000 mcd (full color range -- apparently used for digital camera flash ?) (Digikey)<br />
<br />
Spoke-POV and propeller clocks links:<br />
<br />
* An entire discussion forum devoted to POV displays http://www.ladyada.net.nyud.net:8090/forums/viewforum.php?f=11<br />
** In particular, lots of nice pictures http://www.ladyada.net.nyud.net:8090/forums/viewtopic.php?p=4712<br />
** 'no-microcontroller-programmer-needed' minipov http://www.ladyada.net.nyud.net:8090/forums/viewtopic.php?t=32<br />
* LEDtoy on Sourceforge http://ledtoy.sourceforge.net/<br />
* Ian’s Spoke POV http://www.ianpaterson.org/projects/spokepov20050704/index.htm<br />
* "Propeller Clock" Mechanically Scanned LED Clock: by Bob Blick http://www.bobblick.com/techref/projects/propclock/propclock.html (I think this is the original)<br />
* micro POV display http://positron.org/projects/mpov/ small enough for "glueing it to my shaved head."<br />
<br />
----<br />
<br />
Is this http://led-display-and-design-swicki.eurekster.com/ relevant?</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:DavidCary&diff=4019User talk:DavidCary2007-05-27T03:27:54Z<p>RogerAF: </p>
<hr />
<div>Why don't you help finish my programmable chip eeg project and then use what you learned and the results to then create your own project. Programmers like to reuse working modulas instead of reinventing the wheel.<br />
<br />
<br />
<br />
==a talk through Wiki Howto==<br />
Hi DavidCary<br />
<br>Thank you very much you create this wiki to let us to share electronic projects. <br />
<br>I want to merge the "[[RS232 Dev Board]]" and "[[RS232 RS485 USB Converter Board]]", so want to discuss to the author, Tkb, of "RS232 Dev Board". However, i cannot find out the talk page like i talk to you by this way. Can you point me how to do it?<br />
<br>thanks<br />
<br>[[User:Yan|yan]]<br />
<br />
''If you have a question or comment specifically about the "RS232 Dev Board", please leave a comment on the [[RS232 Dev Board]] page or its "discussion" page.''<br />
''You can click on "[[User talk:Tkb]]" to leave a note on Tkb's user talk page.''<br />
''Since there are more people watching the "RS232 Dev Board" page than Tkb's page, you'll probably get a quicker response if you post to the "RS232 Dev Board" page than to Tkb's page.''<br />
''--[[User:DavidCary|DavidCary]] 20:00, 29 December 2006 (PST)''<br />
<br />
<br />
[[User:Chazegh|Chazegh]] created this "Open Circuits wiki".<br />
I am flattered that you think I had something to do with it.<br />
But since Chazegh seems to be too busy to spend much time here,<br />
it's up to you and I (and whoever else we can recruit) to create content here.<br />
--[[User:DavidCary|DavidCary]] 21:08, 29 December 2006 (PST)<br />
<br />
5.7.2007 Joe Silva:<br />
Hi David, great site! I've taken the liberty to remove some SPAM links from the pages. Yeah we sure do need an anti-valdalism bot. Also maybe not allow anonymous editing.<br />
<br />
----<br />
<br />
Aloha David,<br />
Roger here, I'm still puzzeled as to how to create a new article. I uploaded an image file for the 723 regulator (my article subject). This went into an "Image File page" automatically, OK. I added it to the Voltage Regulators section of Components/Integrated Circuits, OK. But I couldn't figure out how to make a document like there is for LT1528 OO. I put the info I have into the discussion page for the image, but that is only a temporary solution.<br />
<br />
How does one create a new article page that isn't a "talk" page for something else? Beside the info on the IC, I have a couple of documents that are in-depth on using the device. These should be near each other as well as near the info document above. How would I go about setting up a "723" sub-chapter of "Integrated Circuits"? I guess that's as clear as I can make the question.<br />
<br />
I would also like to suggest a modification to the linkage. I'm reading the synopsis on the LT1528, I want to find oout more, so I click on the image, but instead of taking me to an in-depth article, it takes me to the image file page. There I have to look at the Links to find the article (which is only identified as LT1528). I'd like to be taken to the article instead of the image. Take me to the image only if there is no article. Of course this may be more difficult to make happen--I don't know how the site is structured. My web programming is very basic. Still, I think this makes sense from a user's POV.<br />
<br />
Thanks in Advance,<br />
[[User:RogerAF|RAF]] 17:26, 22 May 2007 (PDT)<br />
<br />
Aloha, Roger.<br />
You're doing great.<br />
<br />
I agree that it would be nice if clicking on the picture of the LT1528 took you directly to the article about the LT1528.<br />
I don't know how to fix it.<br />
<br />
Do you see the "Help" link in the navigation bar on the left side of every page?<br />
I think the page it brings up needs a few more tips.<br />
But I want to keep it short and simple.<br />
If I explained every detail, it would become a bloated 100-page document that nobody would read.<br />
<br />
There are already far too many bloated 100-page documents about electronics.<br />
<br />
I hope that you, dear reader, and other volunteers will make Open Circuits into a place where people can learn to do amazing things.<br />
A place that avoids forcing people to learn 100 irrelevant details before learning the one thing they need to know before they get back to building their robot (or whatever).<br />
A place that never makes people throw away good ideas, because we never confuse people into believing that it would be far more complicated and expensive to build than it really is.<br />
<br />
p.s.:<br />
Picking the name of a page is a bit of an art.<br />
Since we want to refer to a page a lot, that's easier when the name is very short.<br />
People new to wiki always pick names that are too long, or have too many capital letters.<br />
Fortunately, it's very simple to rename pages.<br />
You rename pages by clicking on the incorrectly-named "Move this page" button.<br />
(I don't know how to fix that, either).<br />
--[[User:DavidCary|DavidCary]] 10:15, 23 May 2007 (PDT)<br />
<br />
=== making links ===<br />
<br />
Speaking of linkage, making links is one of the most important parts of this wiki.<br />
<br />
Whenever you find one article mentioning some other article, you can click on that word to get more detail.<br />
<br />
If that word is not already clickable (underlined and colored), please make it clickable.<br />
To make a word clickable, hit the "edit" button at the top of the page.<br />
Then add double brackets <nowiki>"[["</nowiki> and <nowiki>"]]"</nowiki> around that word.<br />
(Some people recommend only making the first mention of that word clickable).<br />
<br />
The cheatsheet ( http://en.wikipedia.org/wiki/Wikipedia:Cheatsheet ) calls this an "internal link".<br />
<br />
Here's the trick: you can add those brackets to any word, making it into a link.<br />
Some of those links will go to pages that don't exist yet.<br />
<br />
What happens when you click on one of those links to a page that doesn't exist yet?<br />
<br />
I'm not going to tell you what happens.<br />
Go find out for yourself.<br />
You can practice in the [[meta:Sandbox]].<br />
<br />
--[[User:DavidCary|DavidCary]] 10:15, 23 May 2007 (PDT)<br />
<br />
----<br />
Aloha David,<br />
Roger again; I want to thank you for the info and hints. I'm catching on. I got my component description linked to the caption under the image on the Components/Voltage Regulators page. And I created a "New Article" which I then "moved" to the title of my article. And my article has a link to the description and that has a link to the article, so I'm getting the hang of it. I have several schematics and PC artwork images to upload and link to my article, plus a second article I want to publish (I didn't write it, but I've been unable to find it on the internet--I have a xeroxed copy from 1986 or so and that is the only existing one as far as I know). That article also has several images that go along with it. I wondered about the feasability of uploading a .pdf file (I made one of it) to this site. Would that work? Should I even try? I don't want to screw anything up, but wouldn't that be a lovely thing if we could upload .pdf files? Just a thought.<br />
<br />
Again, Thanks very much, I've made some progress.<br />
<br />
[[User:RogerAF|RAF]] 19:48, 23 May 2007 (PDT)<br />
<br />
Aloha, Roger.<br />
You are welcome.<br />
Have you tried creating a link to an article that doesn't exist yet, just to see what happens when you click on that link? For example, the [[switching regulator]] page that I'm going to start in a few days.<br />
<br />
I don't know about this article that you didn't write.<br />
If the original author wants people to post it widely, and doesn't mind us editing it, then great, let's post it (and give correct attribution).<br />
But some writers go a little crazy when they see that someone random stranger has copied their stuff and posted it to the internet.<br />
(That's why there's that "DO NOT SUBMIT COPYRIGHTED WORK WITHOUT PERMISSION!" note at the bottom of each Edit page).<br />
<br />
I wouldn't mind you posting a .pdf file (that you wrote) temporarily.<br />
It's better than nothing.<br />
But I would expect someone to eventually convert it to text-and-images.<br />
That makes it much easier for the next person to improve the it.<br />
<br />
Thank you again for adding useful information to Open Circuits.<br />
I hope you won't mind people "improving" the things you post here.<br />
<br />
--[[User:DavidCary|DavidCary]] 21:26, 23 May 2007 (PDT)<br />
<br />
Aloha David,<br />
Sorry for the delay, I had a loonng job and then our cable modem failed. At least they swapped us a new one free (hooray RoadRunner). But I want to explain the article: "The Many-Talented 723" by Glenn Prescott. I came across this as a xerox copy sometime around 1985. It was evidently published in a magazine for radio enthusiasts--there are some ads on the last page for radio gear. But the name of the magazine isn't on any of the pages. I Googled for the article and got no returns. I think it is a very good article as far as describing the IC and how to use it. It helped me when I was a beginner, so I want to share it. However, I don't want anyone to get into trouble over it. I just did another search on Google and all the returns refer to my mention of it here on Open Circuits. Like I said, this is a copy that I have, no clue as to the magazine that published it, no copyright date, no nothin'. But I will leave it to your judgement if it is a risk. I still have my own article to get uploaded along with images. I will concentrate on getting mine done before doing anything with the copied article.<br />
<br />
[[User:RogerAF|RAF]] 20:27, 26 May 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=User_talk:DavidCary&diff=3898User talk:DavidCary2007-05-24T02:48:14Z<p>RogerAF: /* a talk through Wiki Howto */</p>
<hr />
<div>Why don't you help finish my programmable chip eeg project and then use what you learned and the results to then create your own project. Programmers like to reuse working modulas instead of reinventing the wheel.<br />
<br />
<br />
<br />
==a talk through Wiki Howto==<br />
Hi DavidCary<br />
<br>Thank you very much you create this wiki to let us to share electronic projects. <br />
<br>I want to merge the "[[RS232 Dev Board]]" and "[[RS232 RS485 USB Converter Board]]", so want to discuss to the author, Tkb, of "RS232 Dev Board". However, i cannot find out the talk page like i talk to you by this way. Can you point me how to do it?<br />
<br>thanks<br />
<br>[[User:Yan|yan]]<br />
<br />
''If you have a question or comment specifically about the "RS232 Dev Board", please leave a comment on the [[RS232 Dev Board]] page or its "discussion" page.''<br />
''You can click on "[[User talk:Tkb]]" to leave a note on Tkb's user talk page.''<br />
''Since there are more people watching the "RS232 Dev Board" page than Tkb's page, you'll probably get a quicker response if you post to the "RS232 Dev Board" page than to Tkb's page.''<br />
''--[[User:DavidCary|DavidCary]] 20:00, 29 December 2006 (PST)''<br />
<br />
<br />
[[User:Chazegh|Chazegh]] created this "Open Circuits wiki".<br />
I am flattered that you think I had something to do with it.<br />
But since Chazegh seems to be too busy to spend much time here,<br />
it's up to you and I (and whoever else we can recruit) to create content here.<br />
--[[User:DavidCary|DavidCary]] 21:08, 29 December 2006 (PST)<br />
<br />
5.7.2007 Joe Silva:<br />
Hi David, great site! I've taken the liberty to remove some SPAM links from the pages. Yeah we sure do need an anti-valdalism bot. Also maybe not allow anonymous editing.<br />
<br />
----<br />
<br />
Aloha David,<br />
Roger here, I'm still puzzeled as to how to create a new article. I uploaded an image file for the 723 regulator (my article subject). This went into an "Image File page" automatically, OK. I added it to the Voltage Regulators section of Components/Integrated Circuits, OK. But I couldn't figure out how to make a document like there is for LT1528 OO. I put the info I have into the discussion page for the image, but that is only a temporary solution.<br />
<br />
How does one create a new article page that isn't a "talk" page for something else? Beside the info on the IC, I have a couple of documents that are in-depth on using the device. These should be near each other as well as near the info document above. How would I go about setting up a "723" sub-chapter of "Integrated Circuits"? I guess that's as clear as I can make the question.<br />
<br />
I would also like to suggest a modification to the linkage. I'm reading the synopsis on the LT1528, I want to find oout more, so I click on the image, but instead of taking me to an in-depth article, it takes me to the image file page. There I have to look at the Links to find the article (which is only identified as LT1528). I'd like to be taken to the article instead of the image. Take me to the image only if there is no article. Of course this may be more difficult to make happen--I don't know how the site is structured. My web programming is very basic. Still, I think this makes sense from a user's POV.<br />
<br />
Thanks in Advance,<br />
[[User:RogerAF|RAF]] 17:26, 22 May 2007 (PDT)<br />
<br />
Aloha, Roger.<br />
You're doing great.<br />
<br />
I agree that it would be nice if clicking on the picture of the LT1528 took you directly to the article about the LT1528.<br />
I don't know how to fix it.<br />
<br />
Do you see the "Help" link in the navigation bar on the left side of every page?<br />
I think the page it brings up needs a few more tips.<br />
But I want to keep it short and simple.<br />
If I explained every detail, it would become a bloated 100-page document that nobody would read.<br />
<br />
There are already far too many bloated 100-page documents about electronics.<br />
<br />
I hope that you, dear reader, and other volunteers will make Open Circuits into a place where people can learn to do amazing things.<br />
A place that avoids forcing people to learn 100 irrelevant details before learning the one thing they need to know before they get back to building their robot (or whatever).<br />
A place that never makes people throw away good ideas, because we never confuse people into believing that it would be far more complicated and expensive to build than it really is.<br />
<br />
p.s.:<br />
Picking the name of a page is a bit of an art.<br />
Since we want to refer to a page a lot, that's easier when the name is very short.<br />
People new to wiki always pick names that are too long, or have too many capital letters.<br />
Fortunately, it's very simple to rename pages.<br />
You rename pages by clicking on the incorrectly-named "Move this page" button.<br />
(I don't know how to fix that, either).<br />
--[[User:DavidCary|DavidCary]] 10:15, 23 May 2007 (PDT)<br />
<br />
=== making links ===<br />
<br />
Speaking of linkage, making links is one of the most important parts of this wiki.<br />
<br />
Whenever you find one article mentioning some other article, you can click on that word to get more detail.<br />
<br />
If that word is not already clickable (underlined and colored), please make it clickable.<br />
To make a word clickable, hit the "edit" button at the top of the page.<br />
Then add double brackets <nowiki>"[["</nowiki> and <nowiki>"]]"</nowiki> around that word.<br />
(Some people recommend only making the first mention of that word clickable).<br />
<br />
The cheatsheet ( http://en.wikipedia.org/wiki/Wikipedia:Cheatsheet ) calls this an "internal link".<br />
<br />
Here's the trick: you can add those brackets to any word, making it into a link.<br />
Some of those links will go to pages that don't exist yet.<br />
<br />
What happens when you click on one of those links to a page that doesn't exist yet?<br />
<br />
I'm not going to tell you what happens.<br />
Go find out for yourself.<br />
You can practice in the [[meta:Sandbox]].<br />
<br />
--[[User:DavidCary|DavidCary]] 10:15, 23 May 2007 (PDT)<br />
<br />
----<br />
Aloha David,<br />
Roger again; I want to thank you for the info and hints. I'm catching on. I got my component description linked to the caption under the image on the Components/Voltage Regulators page. And I created a "New Article" which I then "moved" to the title of my article. And my article has a link to the description and that has a link to the article, so I'm getting the hang of it. I have several schematics and PC artwork images to upload and link to my article, plus a second article I want to publish (I didn't write it, but I've been unable to find it on the internet--I have a xeroxed copy from 1986 or so and that is the only existing one as far as I know). That article also has several images that go along with it. I wondered about the feasability of uploading a .pdf file (I made one of it) to this site. Would that work? Should I even try? I don't want to screw anything up, but wouldn't that be a lovely thing if we could upload .pdf files? Just a thought.<br />
<br />
Again, Thanks very much, I've made some progress.<br />
<br />
[[User:RogerAF|RAF]] 19:48, 23 May 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=The_723_Voltage_Regulator&diff=3894The 723 Voltage Regulator2007-05-24T02:32:51Z<p>RogerAF: /* The 723 Voltage Regulator */</p>
<hr />
<div>== The 723 Voltage Regulator ==<br />
[[Image:UA723CN_Symbol.gif]]<br />
<br />
'''Description:'''<br />
<br />
The 723 is ancient in the world of IC voltage regulators. It is a 14-pin IC that needs some outboard components to tell it what to do. By itself it isn’t that impressive with a current capacity of 150mA, but with the addition of an external series pass transistor it can control whatever current the transistor can handle. It is designed primarily to be used as a positive regulator, but it can also be made to function as a negative regulator. In addition, although it is rated to 37 volts, it can be used in a “floating” mode and regulate voltages above that limit. All in all, I’ve found it to be a very stable, precise, and versatile device.<br />
<br />
The main IC: LM723 is specified at temperatures from -55°C to +125°C. This chip is a little harder to find, and is more expensive than the LM723C which is exactly the same (as far as I know) but for the temperature spec which is from 0°C to +70°C.<br />
<br />
I’m including two other documents about the IC: “The Many Talented 723" by Glen Prescott was my introduction to using it. “[[My Experience With The 723]]” by Roger Furer is my own story of the different regulator circuits I’ve built with it and includes links to schematics and PC Board layouts. (Coming Soon)<br />
<br />
'''Documents:'''<br />
<br />
Several companies manufacture the LM723, but the data sheets are pretty much the same.<br />
<br />
Texas Instruments calls it the µA723:<br />
[http://focus.ti.com/lit/ds/symlink/ua723.pdf]<br />
<br />
National Semiconductor calls it the LM723 and LM723C (reduced temperature version)<br />
[http://cache.national.com/ds/LM/LM723.pdf]<br />
<br />
On Semiconductor never heard of it, but ST Microelectronics makes the LM723 (with various suffixes)<br />
[http://www.st.com/stonline/products/literature/ds/4553/lm723.pdf]<br />
<br />
'''Footprints:'''<br />
<br />
It is available as a 14-pin DIP from everyone. In a metal can: H10C from National, and as an SO-14 from STM and TI. There may be other packages available from other manufacturers, but I limited my search to these three. Note that only the DIP-14 package has the Vz pin--the output from the zener diode which is used for negative regulators. The metal can and the flat-pack do not have enough pins and so they skip this one.<br />
<br />
'''Manufacturer Info:'''<br />
<br />
'''Note: '''<br />
The LM723C is identical to the LM723 except that the LM723C has its performance guaranteed over a 0̊C to +70̊C temperature range, instead of −55̊C to +125̊C.<br />
<br />
<br />
National Semiconductor part # :<br />
<br />
LM723H, LM723H/883, or LM723CH : Metal Can Package (H), NS Package H10C<br />
<br />
LM723J/883 : Ceramic Dual-In-Line Package (J), NS Package J14A<br />
<br />
LM723CN : Molded Dual-In-Line Package (N), NS Package N14A<br />
<br />
<br />
ST Microelectronics part # :<br />
<br />
LM723N : DIP-14<br />
<br />
LM723CN : DIP-14<br />
<br />
LM723CD : SO-14<br />
<br />
<br />
Texas Instruments part # :<br />
<br />
µA723CN : Plastic DIP (N),<br />
<br />
µA723CD : Small Outline (D)<br />
<br />
<br />
NTE makes a substitute: NTE923<br />
<br />
'''Supplier Info:'''<br />
<br />
'''Jameco'''<br />
<br />
Major Brands<br />
<br />
LM723CN, DIP-14, Jameco part# : 24467, price: 1+ 0.34<br />
<br />
LM723H, TO-5, Jameco part# : 301719, price: 1+ 3.69<br />
<br />
Texas Instruments<br />
<br />
UA723CDE4 Jameco part# : 1129851, price: 50+ 0.319<br />
<br />
UA723CNE4 Jameco part# : 1129914, price: 1000+ 0.295<br />
<br />
<br />
National Semiconductor<br />
<br />
LM723CN/NOPB Jameco part# : 840691, price: 10+ 0.482<br />
<br />
<br />
<br />
'''Mouser'''<br />
<br />
Fairchild Semiconductor<br />
<br />
KA723, DIP-14 Mouser part# : 512-KA723, price: 1+ .67<br />
<br />
KA723DTF, SOP-14 Mouser part# : 512-KA723DTF, price: 1+ .67<br />
<br />
<br />
ST Microelectronics<br />
<br />
LM723CD, SO-14 Mouser part# : 511-LM723CD, price: 1+ .38<br />
<br />
LM723CN, DIP-14 Mouser part# : 511-LM723CN, price: 1+ .32<br />
<br />
LM723N, DIP-14 Mouser part# : 511-LM723N, price: 1+ .64<br />
<br />
Texas Instruments<br />
UA723CN, DIP-14 Mouser part# : 595-UA723CN, price: 1+ .53<br />
<br />
<br />
'''Digikey'''<br />
<br />
National Semiconductor<br />
<br />
LM723CH/NOPB, TO-5 Digikey part # : LM723CH-ND, price: 1+ 5.48<br />
<br />
LM723H, TO-5 Digikey part # : LM723H-ND, price: 1+ 5.48<br />
<br />
LM723CN/NOPB, DIP-14 Digikey part # : LM723CNNS-ND, price: 1+ 1.12<br />
<br />
<br />
ST Microelectronics<br />
<br />
LM723N, DIP-14 Digikey part # : 497-4268-5-ND, price: 1+ 0.99<br />
<br />
LM723CD, 14-SOIC Digikey part # : 497-1595-5-ND, price: 1+ 0.86<br />
<br />
<br />
there are more, but you get the idea.</div>RogerAFhttp://www.opencircuits.com/index.php?title=The_723_Voltage_Regulator&diff=3893The 723 Voltage Regulator2007-05-24T02:31:41Z<p>RogerAF: /* The 723 Voltage Regulator */</p>
<hr />
<div>== The 723 Voltage Regulator ==<br />
[[Image:UA723CN_Symbol.gif]]<br />
<br />
'''Description:'''<br />
<br />
The 723 is ancient in the world of IC voltage regulators. It is a 14-pin IC that needs some outboard components to tell it what to do. By itself it isn’t that impressive with a current capacity of 150mA, but with the addition of an external series pass transistor it can control whatever current the transistor can handle. It is designed primarily to be used as a positive regulator, but it can also be made to function as a negative regulator. In addition, although it is rated to 37 volts, it can be used in a “floating” mode and regulate voltages above that limit. All in all, I’ve found it to be a very stable, precise, and versatile device.<br />
<br />
The main IC: LM723 is specified at temperatures from -55°C to +125°C. This chip is a little harder to find, and is more expensive than the LM723C which is exactly the same (as far as I know) but for the temperature spec which is from 0°C to +70°C.<br />
<br />
I’m including two other documents about the IC: “The Many Talented 723" by Glen Prescott was my introduction to using it. “[[My Experience With The 723]]” by Roger Furer is my own story of the different regulator circuits I’ve built with it and includes links to schematics and PC Board layouts.<br />
<br />
'''Documents:'''<br />
<br />
Several companies manufacture the LM723, but the data sheets are pretty much the same.<br />
<br />
Texas Instruments calls it the µA723:<br />
[http://focus.ti.com/lit/ds/symlink/ua723.pdf]<br />
<br />
National Semiconductor calls it the LM723 and LM723C (reduced temperature version)<br />
[http://cache.national.com/ds/LM/LM723.pdf]<br />
<br />
On Semiconductor never heard of it, but ST Microelectronics makes the LM723 (with various suffixes)<br />
[http://www.st.com/stonline/products/literature/ds/4553/lm723.pdf]<br />
<br />
'''Footprints:'''<br />
<br />
It is available as a 14-pin DIP from everyone. In a metal can: H10C from National, and as an SO-14 from STM and TI. There may be other packages available from other manufacturers, but I limited my search to these three. Note that only the DIP-14 package has the Vz pin--the output from the zener diode which is used for negative regulators. The metal can and the flat-pack do not have enough pins and so they skip this one.<br />
<br />
'''Manufacturer Info:'''<br />
<br />
'''Note: '''<br />
The LM723C is identical to the LM723 except that the LM723C has its performance guaranteed over a 0̊C to +70̊C temperature range, instead of −55̊C to +125̊C.<br />
<br />
<br />
National Semiconductor part # :<br />
<br />
LM723H, LM723H/883, or LM723CH : Metal Can Package (H), NS Package H10C<br />
<br />
LM723J/883 : Ceramic Dual-In-Line Package (J), NS Package J14A<br />
<br />
LM723CN : Molded Dual-In-Line Package (N), NS Package N14A<br />
<br />
<br />
ST Microelectronics part # :<br />
<br />
LM723N : DIP-14<br />
<br />
LM723CN : DIP-14<br />
<br />
LM723CD : SO-14<br />
<br />
<br />
Texas Instruments part # :<br />
<br />
µA723CN : Plastic DIP (N),<br />
<br />
µA723CD : Small Outline (D)<br />
<br />
<br />
NTE makes a substitute: NTE923<br />
<br />
'''Supplier Info:'''<br />
<br />
'''Jameco'''<br />
<br />
Major Brands<br />
<br />
LM723CN, DIP-14, Jameco part# : 24467, price: 1+ 0.34<br />
<br />
LM723H, TO-5, Jameco part# : 301719, price: 1+ 3.69<br />
<br />
Texas Instruments<br />
<br />
UA723CDE4 Jameco part# : 1129851, price: 50+ 0.319<br />
<br />
UA723CNE4 Jameco part# : 1129914, price: 1000+ 0.295<br />
<br />
<br />
National Semiconductor<br />
<br />
LM723CN/NOPB Jameco part# : 840691, price: 10+ 0.482<br />
<br />
<br />
<br />
'''Mouser'''<br />
<br />
Fairchild Semiconductor<br />
<br />
KA723, DIP-14 Mouser part# : 512-KA723, price: 1+ .67<br />
<br />
KA723DTF, SOP-14 Mouser part# : 512-KA723DTF, price: 1+ .67<br />
<br />
<br />
ST Microelectronics<br />
<br />
LM723CD, SO-14 Mouser part# : 511-LM723CD, price: 1+ .38<br />
<br />
LM723CN, DIP-14 Mouser part# : 511-LM723CN, price: 1+ .32<br />
<br />
LM723N, DIP-14 Mouser part# : 511-LM723N, price: 1+ .64<br />
<br />
Texas Instruments<br />
UA723CN, DIP-14 Mouser part# : 595-UA723CN, price: 1+ .53<br />
<br />
<br />
'''Digikey'''<br />
<br />
National Semiconductor<br />
<br />
LM723CH/NOPB, TO-5 Digikey part # : LM723CH-ND, price: 1+ 5.48<br />
<br />
LM723H, TO-5 Digikey part # : LM723H-ND, price: 1+ 5.48<br />
<br />
LM723CN/NOPB, DIP-14 Digikey part # : LM723CNNS-ND, price: 1+ 1.12<br />
<br />
<br />
ST Microelectronics<br />
<br />
LM723N, DIP-14 Digikey part # : 497-4268-5-ND, price: 1+ 0.99<br />
<br />
LM723CD, 14-SOIC Digikey part # : 497-1595-5-ND, price: 1+ 0.86<br />
<br />
<br />
there are more, but you get the idea.</div>RogerAFhttp://www.opencircuits.com/index.php?title=The_723_Voltage_Regulator&diff=3892The 723 Voltage Regulator2007-05-24T02:31:19Z<p>RogerAF: /* The 723 Voltage Regulator */</p>
<hr />
<div>== The 723 Voltage Regulator ==<br />
[[Image:UA723CN_Symbol.gif]]<br />
<br />
'''Description:'''<br />
<br />
The 723 is ancient in the world of IC voltage regulators. It is a 14-pin IC that needs some outboard components to tell it what to do. By itself it isn’t that impressive with a current capacity of 150mA, but with the addition of an external series pass transistor it can control whatever current the transistor can handle. It is designed primarily to be used as a positive regulator, but it can also be made to function as a negative regulator. In addition, although it is rated to 37 volts, it can be used in a “floating” mode and regulate voltages above that limit. All in all, I’ve found it to be a very stable, precise, and versatile device.<br />
<br />
The main IC: LM723 is specified at temperatures from -55°C to +125°C. This chip is a little harder to find, and is more expensive than the LM723C which is exactly the same (as far as I know) but for the temperature spec which is from 0°C to +70°C.<br />
<br />
I’m including two other documents about the IC: “The Many Talented 723" by Glen Prescott was my introduction to using it. “[[My Experience With The 723]]” by Roger Furer is my own story of the different regulator circuits I’ve built with it and includes links to schematics and PC Board layouts.<br />
<br />
'''Documents:'''<br />
<br />
Several companies manufacture the LM723, but the data sheets are pretty much the same.<br />
<br />
Texas Instruments calls it the µA723:<br />
[http://focus.ti.com/lit/ds/symlink/ua723.pdf]<br />
<br />
National Semiconductor calls it the LM723 and LM723C (reduced temperature version)<br />
[http://cache.national.com/ds/LM/LM723.pdf]<br />
<br />
On Semiconductor never heard of it, but ST Microelectronics makes the LM723 (with various suffixes)<br />
[http://www.st.com/stonline/products/literature/ds/4553/lm723.pdf]<br />
<br />
'''Footprints:'''<br />
<br />
It is available as a 14-pin DIP from everyone. In a metal can: H10C from National, and as an SO-14 from STM and TI. There may be other packages available from other manufacturers, but I limited my search to these three. Note that only the DIP-14 package has the Vz pin--the output from the zener diode which is used for negative regulators. The metal can and the flat-pack do not have enough pins and so they skip this one.<br />
<br />
'''Manufacturer Info:'''<br />
<br />
'''Note: '''<br />
The LM723C is identical to the LM723 except that the LM723C has its performance guaranteed over a 0̊C to +70̊C temperature range, instead of −55̊C to +125̊C.<br />
<br />
<br />
National Semiconductor part # :<br />
<br />
LM723H, LM723H/883, or LM723CH : Metal Can Package (H), NS Package H10C<br />
<br />
LM723J/883 : Ceramic Dual-In-Line Package (J), NS Package J14A<br />
<br />
LM723CN : Molded Dual-In-Line Package (N), NS Package N14A<br />
<br />
<br />
ST Microelectronics part # :<br />
<br />
LM723N : DIP-14<br />
<br />
LM723CN : DIP-14<br />
<br />
LM723CD : SO-14<br />
<br />
<br />
Texas Instruments part # :<br />
<br />
µA723CN : Plastic DIP (N),<br />
<br />
µA723CD : Small Outline (D)<br />
<br />
<br />
NTE makes a substitute: NTE923<br />
<br />
'''Supplier Info:'''<br />
<br />
'''Jameco'''<br />
<br />
Major Brands<br />
<br />
LM723CN, DIP-14, Jameco part# : 24467, price: 1+ 0.34<br />
<br />
LM723H, TO-5, Jameco part# : 301719, price: 1+ 3.69<br />
<br />
Texas Instruments<br />
<br />
UA723CDE4 Jameco part# : 1129851, price: 50+ 0.319<br />
<br />
UA723CNE4 Jameco part# : 1129914, price: 1000+ 0.295<br />
<br />
<br />
National Semiconductor<br />
<br />
LM723CN/NOPB Jameco part# : 840691, price: 10+ 0.482<br />
<br />
<br />
<br />
'''Mouser'''<br />
<br />
Fairchild Semiconductor<br />
<br />
KA723, DIP-14 Mouser part# : 512-KA723, price: 1+ .67<br />
<br />
KA723DTF, SOP-14 Mouser part# : 512-KA723DTF, price: 1+ .67<br />
<br />
<br />
ST Microelectronics<br />
<br />
LM723CD, SO-14 Mouser part# : 511-LM723CD, price: 1+ .38<br />
<br />
LM723CN, DIP-14 Mouser part# : 511-LM723CN, price: 1+ .32<br />
<br />
LM723N, DIP-14 Mouser part# : 511-LM723N, price: 1+ .64<br />
<br />
Texas Instruments<br />
UA723CN, DIP-14 Mouser part# : 595-UA723CN, price: 1+ .53<br />
<br />
<br />
'''Digikey'''<br />
<br />
National Semiconductor<br />
<br />
LM723CH/NOPB, TO-5 Digikey part # : LM723CH-ND, price: 1+ 5.48<br />
<br />
LM723H, TO-5 Digikey part # : LM723H-ND, price: 1+ 5.48<br />
<br />
LM723CN/NOPB, DIP-14 Digikey part # : LM723CNNS-ND, price: 1+ 1.12<br />
<br />
<br />
ST Microelectronics<br />
<br />
LM723N, DIP-14 Digikey part # : 497-4268-5-ND, price: 1+ 0.99<br />
<br />
LM723CD, 14-SOIC Digikey part # : 497-1595-5-ND, price: 1+ 0.86<br />
<br />
<br />
there are more, but you get the idea.</div>RogerAFhttp://www.opencircuits.com/index.php?title=My_Experience_With_The_723&diff=3891My Experience With The 7232007-05-24T02:29:45Z<p>RogerAF: </p>
<hr />
<div>== My Experience With the 723 Voltage Regulator IC ==<br />
<br />
'''Introduction:'''<br />
<br />
I came across [[The 723 Voltage Regulator]] in the 1980s and thought it was much too complicated to use. I liked the 3-terminal regulators and stayed with them until I had to make a power supply that would handle more current than they could supply. In the mid ‘80s I’d come across a copy of an article called “The Many Talented 723" by Glen Prescott. I don’t know where this was published and I’ve been unable to locate it through Google. However I still have my copy and I decided it was worth scanning and cleaning up the figures, so I can share it with the world.<br />
<br />
There are a couple of companies who make the device, that describe it in their data sheet titles as a “Precision Voltage Regulator”. This is what it is. If you were to design a voltage regulator from scratch, using discrete components. You’d want to end up with something like the 723. I’m not going to go into detail about it, because the data sheets and Mr. Prescott’s article do that very well already. I just want to share some of my experiences in the use of it.<br />
<br />
<br />
'''My First Mixer Power Supply:'''<br />
<br />
I built a little microphone mixer while I was in electronics school and I needed a power supply for it. I had a pair of LM723 ICs in a drawer, but I’d never worked with the chip. I decided that I should learn about it. The National Semiconductor Linear data book showed a lot of different ways to use it and decided to build a plus and minus 15 volt supply with external pass devices. I included trimmers for fine tuning the outputs and I had a little aluminum case that I could fit the transformer, rectifier, filter capacitors, and PC board into. I used a sharpie pen and drew the layout by hand except for the IC patterns. I etched the board and assembled it. It powered my mixer very nicely and I got an A in that class.<br />
<br />
Last year I started experimenting with an Analog Devices AD7329–a 13-bit, 8 channel A to D converter which requires ±15V as well as 5V supplies. I dusted my little power supply off (it is over 20 years old now) tuned it on and checked the outputs. I thought I’d probably need to adjust the trimmers some, but even after sitting for the last 20 years, it was measuring +14.998V and -15.01V. I was very impressed and decided it was too nice to leave in a box. So it is out of retirement and I use it for my experiments on my bench whenever I’m working with op-amps that need ±15V.<br />
<br />
<br />
'''Second Mixer Power Supply:'''<br />
<br />
I service several recording studios here in Honolulu. One of my clients has a console whose power supply failed. It had failed before and I’d replaced the regulators, which were high current (7 amps) devices in TO3 packages. But the last time it failed I could not find replacements. I’ve forgotten the part number of the device, but it does not seem to be made any more and no one has produced a substitute.<br />
<br />
My client was understandably upset. Recording studios need to have working equipment–especially the mixing console. I told him I’d need at least 48 hours if not 72 to build replacement regulators. He said to hurry.<br />
<br />
I used the same circuit as in my little mixer supply above. I hand wired it on pad-per-hole perfboard and had the regulator cards complete in 30 hours. I got the positive regulator working with a 2N3055 transistor as the NPN series pass device. But when I tried to use the PNP compliment–2N2955 transistor, I could not get it to produce 15V at 7 amps. I finally figured out that the chip, since it uses the Vz pin in the negative configuration, just doesn’t have the same drive capability as it does when using the output pin in the positive configuration.<br />
<br />
The clock was ticking and I was sweating, when I thought of trying a Darlington transistor. I had just purchased some a few days before, so I had them on hand, at midnight with no parts stores open. That proved to be the solution and so I switched the 2N3055 on the positive side for the NPN Darlington compliment of the transistor I had on the negative side. The devices are sold as a complimentary pair at a couple of local electronics stores. This was one of my design objectives, so in case of emergency, the parts are available locally.<br />
<br />
The TO3 packages of the external series pass transistors went into the same holes on the heat-sink as the original regulators. A couple of stand-offs support the cards with the 723s. I connected the regulator inputs to the filter caps and the transistor outputs to the fuses, and the studio was back in business.<br />
<br />
<br />
'''Current Limiting:'''<br />
<br />
The 723 has built in current limiting, but it is designed as a positive regulator. So there is no provision for current limiting in a negative configuration. Also current limiting is dependent on a resistor which must handle the maximum current the regulator is designed to supply. In the case of large currents >1 amp, this produces significant heat. I left the current limiting out of my designs. I didn’t want to have only the positive half of the supply getting limited while the negative half operated with no limit. I reasoned that since the supply outputs were fused, there was already protection in place.<br />
<br />
This is the case with all the regulator designs I present here. If you need current limiting and you just need a positive regulator, the 723 can easily accommodate you. Just figure out how much current you need to supply and how much over that you’re willing to tolerate, then calculate ILimit = Vsense / RSC.<br />
<br />
The regulator is also capable of foldback current limiting where there is a “knee” region before full shutdown occurs. Personally I have never used the current limiting features, so I cannot write from experience. If the supply is to be used in an application where shorting or over currents are possible, I use fuses.<br />
<br />
<br />
'''Low Voltage Supply:'''<br />
<br />
When I began experimenting with embedded processors, I found that many needed supplies in the 3V to 4V range. By this time I had become fairly adept at using the 723 and since I had some still, I decided to use one, rather than investing in a fixed low voltage regulator. I went with a positive output using an external PNP transistor. Again, I added a trimmer pot, so I can adjust from around 2.75V to 4.25V. This little board (the transistor has a TO92 package) measures only 1" x 2" and has a power on LED indicator, and two–2-pole screw terminal blocks. It has been very handy.<br />
<br />
<br />
'''“Big Bertha” Bench Supply:'''<br />
<br />
In the world of professional audio, the Jensen 990 discrete opamp is a famous classic. Designed to work with ±24V power supplies, it is considered the “holy grail” of opamp designs. I have worked on MCI’s JH500 series consoles which have ±36V power supply rails–they use a high voltage opamp like the TI OPA544 and add a NPN/PNP output buffer to each. The whole console is filled with these–talk about an air conditioning bill. But having these high voltage rails means the audio signal can reach large levels of voltage swing and go onto the tape as hot as you can stand it. Of course this is analog. With digital there is no need for this. But there are audio people who prefer analog, and a high voltage opamp can add to the sound of the console.<br />
<br />
I have another client who records to digital media, but mixes on an analog console. He had me modify the console master stage with discrete opamps running on their own separate ±24V power supply. He felt that it made the mixes sound better. I can’t say for sure, I was not exposed to listening to it every day, but I have no reason to doubt it. He gets a lot of work coming into his studio.<br />
<br />
But the story here is about “Big Bertha”. I decided I want to design a modern version of the Jensen 990 and I might as well make it able to operate at ±36V. To do this effectively I needed a suitable power supply. I built one using two 36V transformers in series. I regulated it with a pair of 723s and 20A Darlington transistors. I don’t plan on drawing anywhere near that amount of current, I just had them on hand. In fact everything I used to build “Big Bertha” was residing in drawers and boxes at my shop. (One of the design goals was to make it without spending any money.)<br />
<br />
Actually the unregulated supply is around ±56V. This is beyond the 723's input voltage limit. I could have made floating regulators (more on those later), but I decided to try “amplified zeners” instead. I came across the “amplified zener” in “The Power Supply Handbook” by the editors of 73 magazine. I’ve used it over the years, when I’d get stuck for a solution. It has several clever ideas that have proved very useful, the amplified zener being one of them. Basically you take a zener diode and a transistor and connect them so the zener’s cathode is at the transistor base, and the transistor collector is the zener’s anode. No resistor needed as long as you avoid the knee region of the zener. I used this trick to knock the unregulated supply down to around ±38V (the 723 max input is 40V). I have these squarish heat sinks that can hold TO3 devices and I stacked 4 of them together; 2 on top of 2, so my amplified zeners and the Darlington pass devices are contained in an area that is the perfect size for a 5" fan, should I ever need to draw so much current that things get warm. So far that hasn’t happened. I can adjust the output from around 12V to just over 30V. I know it isn’t up to the ±36V of the MCI JH500, but I decided that wasn’t really needed. If someone wants an op amp to handle that, I’ll use the OPA544.<br />
<br />
I haven’t really had a chance to put “Big Bertha” to the test. Mostly I’ve used her to power breadboard circuits at around ±18V. This is what Amek and SSL consoles operate at and those are what my remaining clients have. The computer revolution put most of the recording studios in Honolulu out of business.<br />
<br />
Still, I like the idea of having a supply that can give me that kind of voltage range with a rock solid regulation that doesn’t drift or sag.<br />
<br />
<br />
'''Closing Thoughts:'''<br />
<br />
The 723 is a versatile voltage regulator. According to National Semiconductor’s data sheet: “The LM723/LM723C is also useful in a wide range of other applications such as a shunt regulator, a current regulator or a temperature controller.” And “Can be used as either a linear or a switching regulator”.<br />
<br />
I have only used it as a linear series regulator and I’ve been pleased with the results. I have just started experimenting with switching regulators. I built my first one with a TL494 PWM controller. I will probably try out the 723 in that mode of operation when I have some time on my hands and no other projects waiting. But that may be a while, so if anyone has actually done it, I’d appreciate it if you’d share the info.<br />
<br />
I hope this article is useful and I welcome comments and ideas.<br />
<br />
[[User:RogerAF|RAF]] 19:04, 23 May 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=My_Experience_With_The_723&diff=3889My Experience With The 7232007-05-24T02:26:27Z<p>RogerAF: New Article moved to My Experience With The 723</p>
<hr />
<div>== My Experience With the 723 Voltage Regulator IC ==<br />
<br />
'''Introduction:'''<br />
<br />
I came across the LM723 in the 1980s and thought it was much too complicated to use. I liked the 3-terminal regulators and stayed with them until I had to make a power supply that would handle more current than they could supply. In the mid ‘80s I’d come across a copy of an article called “The Many Talented 723" by Glen Prescott. I don’t know where this was published and I’ve been unable to locate it through Google. However I still have my copy and I decided it was worth scanning and cleaning up the figures, so I can share it with the world.<br />
<br />
There are a couple of companies who make the device, that describe it in their data sheet titles as a “Precision Voltage Regulator”. This is what it is. If you were to design a voltage regulator from scratch, using discrete components. You’d want to end up with something like the 723. I’m not going to go into detail about it, because the data sheets and Mr. Prescott’s article do that very well already. I just want to share some of my experiences in the use of it.<br />
<br />
<br />
'''My First Mixer Power Supply:'''<br />
<br />
I built a little microphone mixer while I was in electronics school and I needed a power supply for it. I had a pair of LM723 ICs in a drawer, but I’d never worked with the chip. I decided that I should learn about it. The National Semiconductor Linear data book showed a lot of different ways to use it and decided to build a plus and minus 15 volt supply with external pass devices. I included trimmers for fine tuning the outputs and I had a little aluminum case that I could fit the transformer, rectifier, filter capacitors, and PC board into. I used a sharpie pen and drew the layout by hand except for the IC patterns. I etched the board and assembled it. It powered my mixer very nicely and I got an A in that class.<br />
<br />
Last year I started experimenting with an Analog Devices AD7329–a 13-bit, 8 channel A to D converter which requires ±15V as well as 5V supplies. I dusted my little power supply off (it is over 20 years old now) tuned it on and checked the outputs. I thought I’d probably need to adjust the trimmers some, but even after sitting for the last 20 years, it was measuring +14.998V and -15.01V. I was very impressed and decided it was too nice to leave in a box. So it is out of retirement and I use it for my experiments on my bench whenever I’m working with op-amps that need ±15V.<br />
<br />
<br />
'''Second Mixer Power Supply:'''<br />
<br />
I service several recording studios here in Honolulu. One of my clients has a console whose power supply failed. It had failed before and I’d replaced the regulators, which were high current (7 amps) devices in TO3 packages. But the last time it failed I could not find replacements. I’ve forgotten the part number of the device, but it does not seem to be made any more and no one has produced a substitute.<br />
<br />
My client was understandably upset. Recording studios need to have working equipment–especially the mixing console. I told him I’d need at least 48 hours if not 72 to build replacement regulators. He said to hurry.<br />
<br />
I used the same circuit as in my little mixer supply above. I hand wired it on pad-per-hole perfboard and had the regulator cards complete in 30 hours. I got the positive regulator working with a 2N3055 transistor as the NPN series pass device. But when I tried to use the PNP compliment–2N2955 transistor, I could not get it to produce 15V at 7 amps. I finally figured out that the chip, since it uses the Vz pin in the negative configuration, just doesn’t have the same drive capability as it does when using the output pin in the positive configuration.<br />
<br />
The clock was ticking and I was sweating, when I thought of trying a Darlington transistor. I had just purchased some a few days before, so I had them on hand, at midnight with no parts stores open. That proved to be the solution and so I switched the 2N3055 on the positive side for the NPN Darlington compliment of the transistor I had on the negative side. The devices are sold as a complimentary pair at a couple of local electronics stores. This was one of my design objectives, so in case of emergency, the parts are available locally.<br />
<br />
The TO3 packages of the external series pass transistors went into the same holes on the heat-sink as the original regulators. A couple of stand-offs support the cards with the 723s. I connected the regulator inputs to the filter caps and the transistor outputs to the fuses, and the studio was back in business.<br />
<br />
<br />
'''Current Limiting:'''<br />
<br />
The 723 has built in current limiting, but it is designed as a positive regulator. So there is no provision for current limiting in a negative configuration. Also current limiting is dependent on a resistor which must handle the maximum current the regulator is designed to supply. In the case of large currents >1 amp, this produces significant heat. I left the current limiting out of my designs. I didn’t want to have only the positive half of the supply getting limited while the negative half operated with no limit. I reasoned that since the supply outputs were fused, there was already protection in place.<br />
<br />
This is the case with all the regulator designs I present here. If you need current limiting and you just need a positive regulator, the 723 can easily accommodate you. Just figure out how much current you need to supply and how much over that you’re willing to tolerate, then calculate ILimit = Vsense / RSC.<br />
<br />
The regulator is also capable of foldback current limiting where there is a “knee” region before full shutdown occurs. Personally I have never used the current limiting features, so I cannot write from experience. If the supply is to be used in an application where shorting or over currents are possible, I use fuses.<br />
<br />
<br />
'''Low Voltage Supply:'''<br />
<br />
When I began experimenting with embedded processors, I found that many needed supplies in the 3V to 4V range. By this time I had become fairly adept at using the 723 and since I had some still, I decided to use one, rather than investing in a fixed low voltage regulator. I went with a positive output using an external PNP transistor. Again, I added a trimmer pot, so I can adjust from around 2.75V to 4.25V. This little board (the transistor has a TO92 package) measures only 1" x 2" and has a power on LED indicator, and two–2-pole screw terminal blocks. It has been very handy.<br />
<br />
<br />
'''“Big Bertha” Bench Supply:'''<br />
<br />
In the world of professional audio, the Jensen 990 discrete opamp is a famous classic. Designed to work with ±24V power supplies, it is considered the “holy grail” of opamp designs. I have worked on MCI’s JH500 series consoles which have ±36V power supply rails–they use a high voltage opamp like the TI OPA544 and add a NPN/PNP output buffer to each. The whole console is filled with these–talk about an air conditioning bill. But having these high voltage rails means the audio signal can reach large levels of voltage swing and go onto the tape as hot as you can stand it. Of course this is analog. With digital there is no need for this. But there are audio people who prefer analog, and a high voltage opamp can add to the sound of the console.<br />
<br />
I have another client who records to digital media, but mixes on an analog console. He had me modify the console master stage with discrete opamps running on their own separate ±24V power supply. He felt that it made the mixes sound better. I can’t say for sure, I was not exposed to listening to it every day, but I have no reason to doubt it. He gets a lot of work coming into his studio.<br />
<br />
But the story here is about “Big Bertha”. I decided I want to design a modern version of the Jensen 990 and I might as well make it able to operate at ±36V. To do this effectively I needed a suitable power supply. I built one using two 36V transformers in series. I regulated it with a pair of 723s and 20A Darlington transistors. I don’t plan on drawing anywhere near that amount of current, I just had them on hand. In fact everything I used to build “Big Bertha” was residing in drawers and boxes at my shop. (One of the design goals was to make it without spending any money.)<br />
<br />
Actually the unregulated supply is around ±56V. This is beyond the 723's input voltage limit. I could have made floating regulators (more on those later), but I decided to try “amplified zeners” instead. I came across the “amplified zener” in “The Power Supply Handbook” by the editors of 73 magazine. I’ve used it over the years, when I’d get stuck for a solution. It has several clever ideas that have proved very useful, the amplified zener being one of them. Basically you take a zener diode and a transistor and connect them so the zener’s cathode is at the transistor base, and the transistor collector is the zener’s anode. No resistor needed as long as you avoid the knee region of the zener. I used this trick to knock the unregulated supply down to around ±38V (the 723 max input is 40V). I have these squarish heat sinks that can hold TO3 devices and I stacked 4 of them together; 2 on top of 2, so my amplified zeners and the Darlington pass devices are contained in an area that is the perfect size for a 5" fan, should I ever need to draw so much current that things get warm. So far that hasn’t happened. I can adjust the output from around 12V to just over 30V. I know it isn’t up to the ±36V of the MCI JH500, but I decided that wasn’t really needed. If someone wants an op amp to handle that, I’ll use the OPA544.<br />
<br />
I haven’t really had a chance to put “Big Bertha” to the test. Mostly I’ve used her to power breadboard circuits at around ±18V. This is what Amek and SSL consoles operate at and those are what my remaining clients have. The computer revolution put most of the recording studios in Honolulu out of business.<br />
<br />
Still, I like the idea of having a supply that can give me that kind of voltage range with a rock solid regulation that doesn’t drift or sag.<br />
<br />
<br />
'''Closing Thoughts:'''<br />
<br />
The 723 is a versatile voltage regulator. According to National Semiconductor’s data sheet: “The LM723/LM723C is also useful in a wide range of other applications such as a shunt regulator, a current regulator or a temperature controller.” And “Can be used as either a linear or a switching regulator”.<br />
<br />
I have only used it as a linear series regulator and I’ve been pleased with the results. I have just started experimenting with switching regulators. I built my first one with a TL494 PWM controller. I will probably try out the 723 in that mode of operation when I have some time on my hands and no other projects waiting. But that may be a while, so if anyone has actually done it, I’d appreciate it if you’d share the info.<br />
<br />
I hope this article is useful and I welcome comments and ideas.<br />
<br />
[[User:RogerAF|RAF]] 19:04, 23 May 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=New_Article&diff=3890New Article2007-05-24T02:26:27Z<p>RogerAF: New Article moved to My Experience With The 723</p>
<hr />
<div>#redirect [[My Experience With The 723]]</div>RogerAFhttp://www.opencircuits.com/index.php?title=Integrated_Circuits&diff=3888Integrated Circuits2007-05-24T02:24:05Z<p>RogerAF: /* Voltage Regulators */</p>
<hr />
<div>== Digital Potentiometers ==<br />
[[Digital Potentiometers|Digital Potentiometers(AD5204)]]<br />
The digital Potentiometers made by analog devices (AD5204) has 255 positions can be adjusted by the microcomputer that can receive commands from the computer. This is a great way for analog circuitry to have digital control. This is a chip with 4 digitally controlled POTs and the pots can be daisy chained to have multiple chips controled by a single SPI interface.<br />
<br />
<br />
<br />
== Voltage Regulators ==<br />
{|<br />
! colspan="2" align="left"| Linear Regulators<br />
|-<br />
| align="center"|[[Image:Main-LT1528.jpg|69px|LT1528]]<br>[[LT1528]]<br />
| High current, Variable Voltage Regulator<br />
|-<br />
| align="center"|[[Image:TPS-V-Reg.jpg|69px|TPS V-Reg]]<br>[[TPS V-Regs]]<br />
| These are 3.3V and 5V LDO, Low-Noise Voltage Regulators. Very small SOT-23 SMD package. 150mA max current. Best used in battery applications.<br />
|-<br />
| align="center"|[[Image:Main-LM7805.jpg|69px]]<br>[[Basic Voltage Regulators]]<br />
| Variable voltage regulators, set output regulators, we give you the whole breakdown. Perfect for use with an external wall-wart power supply.<br />
|-<br />
| align="center"| [[Image:UA723CN_Symbol.gif]]<br>[[The 723 Voltage Regulator]]<br />
| Precision Voltage Regulator. Can be used as fixed or floating, variable, linear or switching. <br />
'''NOTE:''' Only the DIP-14 version (image) has the Vz pin, which is used for negative regulators. The Metal Can and the Flat-Pack do not have enough pins so exclude the Vz.<br />
|-<br />
| &nbsp;<br />
|-<br />
! colspan="2" align="left"| Switching Regulators<br />
|-<br />
| align="center"| [[Image:MCP1253-ADJ.png|69px]]<br>[[MCP1252/3]]<br />
| Extremely Efficient, 120mA Flyback Switching Regulators.<br />
|-<br />
|}<br />
<br />
== Microcontrollers ==<br />
<br />
* [[Image:lpc2103.jpg|69px|LPC2103]] [http://www.k9spud.com/arm/lpc2103/ LPC2103] Low cost 70MHz ARM7TDMI-S FLASH Microcontroller from Philips. The [http://coridiumcorp.com/arm7/ "$49" "Coridium ARMmite"] does use this chip.<br />
* [[Atmel]] AVR 8 bit FLASH microcontrollers<br />
* [[Microchip]] PIC 8 bit FLASH microcontrollers<br />
* Microchip dsPIC 16 bit FLASH microcontrollers ( [[DsPIC30F 5011 Development Board]] )<br />
* Cypress PSoC 8 bit FLASH microcontrollers<br />
<br />
''I've written a little about the various kinds of microcontrollers at [http://en.wikibooks.org/wiki/Embedded_Systems/Particular_Microprocessors Wikibooks: Embedded Systems]. --[[User:DavidCary|DavidCary]] 06:15, 10 March 2007 (PST)''<br />
<br />
== Op Amps ==<br />
<br />
Op amps and instrumentation amps.<br />
<br />
[[op amp]]s: great for amplifying weak signals from [[sensors]] to a more useful level. Also used in filters, integrators, etc. <br />
<br />
* [[LT1168|LT1168 Programmable-Gain Precision Instrumentation Amplifier]] - Low Power, Single Resistor Gain Programmable, Precision Instrumentation Amplifier<br />
* [[LT1114|LT1114 Low Power Precision OP-Amps]] are used for amplification and filtering of the signal - Dual/Quad Low Power Precision, Picoamp Input Op Amps<br />
<br />
* [http://en.wikibooks.org/wiki/Electronics/Op-Amps Wikibooks:Op-Amps] has a "quick design process" using Daisy's theorem: ''"The sum of the gains = +1 in a properly-designed op amp circuit."''<br />
<br />
* [http://ciphersbyritter.com/RADELECT/PREOPAMP/OPAMPDSN.HTM "Some Op Amp Audio Design Issues"] by Terry Ritter<br />
<br />
== logic gates ==<br />
<br />
* NAND gate: [http://www.coprolite.com/art48.html "Using a NAND Gate for a Set/Reset Latch"] (the 74HC132 Schmitt-trigger quad NAND is better than the 74HC00 quad NAND).<br />
* [http://people.freenet.de/dieter.02/alu_4.htm "Multiplexers: the tactical Nuke of Logic Design"] by Dieter Mueller 2004 (74153)<br />
<br />
There are hundreds of other specialized logic gates. Here we only list the ones we actually use in some Open Circuit [[Projects|Project]]:<br />
<br />
* 74HC595 eight bit shift register with output latch (used for POV display)<br />
<br />
[[Category:Components]]</div>RogerAFhttp://www.opencircuits.com/index.php?title=Integrated_Circuits&diff=3887Integrated Circuits2007-05-24T02:19:18Z<p>RogerAF: /* Voltage Regulators */</p>
<hr />
<div>== Digital Potentiometers ==<br />
[[Digital Potentiometers|Digital Potentiometers(AD5204)]]<br />
The digital Potentiometers made by analog devices (AD5204) has 255 positions can be adjusted by the microcomputer that can receive commands from the computer. This is a great way for analog circuitry to have digital control. This is a chip with 4 digitally controlled POTs and the pots can be daisy chained to have multiple chips controled by a single SPI interface.<br />
<br />
<br />
<br />
== Voltage Regulators ==<br />
{|<br />
! colspan="2" align="left"| Linear Regulators<br />
|-<br />
| align="center"|[[Image:Main-LT1528.jpg|69px|LT1528]]<br>[[LT1528]]<br />
| High current, Variable Voltage Regulator<br />
|-<br />
| align="center"|[[Image:TPS-V-Reg.jpg|69px|TPS V-Reg]]<br>[[TPS V-Regs]]<br />
| These are 3.3V and 5V LDO, Low-Noise Voltage Regulators. Very small SOT-23 SMD package. 150mA max current. Best used in battery applications.<br />
|-<br />
| align="center"|[[Image:Main-LM7805.jpg|69px]]<br>[[Basic Voltage Regulators]]<br />
| Variable voltage regulators, set output regulators, we give you the whole breakdown. Perfect for use with an external wall-wart power supply.<br />
|-<br />
| align="center"| [[Image:UA723CN_Symbol.gif]]<br>[[The 723 - DIP-14]]<br />
| [[The 723 Voltage Regulator]]<br />
<br />
Precision Voltage Regulator. Can be used as fixed or floating, variable, linear or switching. '''NOTE:''' Only the DIP-14 version has the Vz pin, which is used for negative regulators. The Metal Can and the Flat-Pack do not have enough pins so exclude the Vz.<br />
|-<br />
| &nbsp;<br />
|-<br />
! colspan="2" align="left"| Switching Regulators<br />
|-<br />
| align="center"| [[Image:MCP1253-ADJ.png|69px]]<br>[[MCP1252/3]]<br />
| Extremely Efficient, 120mA Flyback Switching Regulators.<br />
|-<br />
|}<br />
<br />
== Microcontrollers ==<br />
<br />
* [[Image:lpc2103.jpg|69px|LPC2103]] [http://www.k9spud.com/arm/lpc2103/ LPC2103] Low cost 70MHz ARM7TDMI-S FLASH Microcontroller from Philips. The [http://coridiumcorp.com/arm7/ "$49" "Coridium ARMmite"] does use this chip.<br />
* [[Atmel]] AVR 8 bit FLASH microcontrollers<br />
* [[Microchip]] PIC 8 bit FLASH microcontrollers<br />
* Microchip dsPIC 16 bit FLASH microcontrollers ( [[DsPIC30F 5011 Development Board]] )<br />
* Cypress PSoC 8 bit FLASH microcontrollers<br />
<br />
''I've written a little about the various kinds of microcontrollers at [http://en.wikibooks.org/wiki/Embedded_Systems/Particular_Microprocessors Wikibooks: Embedded Systems]. --[[User:DavidCary|DavidCary]] 06:15, 10 March 2007 (PST)''<br />
<br />
== Op Amps ==<br />
<br />
Op amps and instrumentation amps.<br />
<br />
[[op amp]]s: great for amplifying weak signals from [[sensors]] to a more useful level. Also used in filters, integrators, etc. <br />
<br />
* [[LT1168|LT1168 Programmable-Gain Precision Instrumentation Amplifier]] - Low Power, Single Resistor Gain Programmable, Precision Instrumentation Amplifier<br />
* [[LT1114|LT1114 Low Power Precision OP-Amps]] are used for amplification and filtering of the signal - Dual/Quad Low Power Precision, Picoamp Input Op Amps<br />
<br />
* [http://en.wikibooks.org/wiki/Electronics/Op-Amps Wikibooks:Op-Amps] has a "quick design process" using Daisy's theorem: ''"The sum of the gains = +1 in a properly-designed op amp circuit."''<br />
<br />
* [http://ciphersbyritter.com/RADELECT/PREOPAMP/OPAMPDSN.HTM "Some Op Amp Audio Design Issues"] by Terry Ritter<br />
<br />
== logic gates ==<br />
<br />
* NAND gate: [http://www.coprolite.com/art48.html "Using a NAND Gate for a Set/Reset Latch"] (the 74HC132 Schmitt-trigger quad NAND is better than the 74HC00 quad NAND).<br />
* [http://people.freenet.de/dieter.02/alu_4.htm "Multiplexers: the tactical Nuke of Logic Design"] by Dieter Mueller 2004 (74153)<br />
<br />
There are hundreds of other specialized logic gates. Here we only list the ones we actually use in some Open Circuit [[Projects|Project]]:<br />
<br />
* 74HC595 eight bit shift register with output latch (used for POV display)<br />
<br />
[[Category:Components]]</div>RogerAFhttp://www.opencircuits.com/index.php?title=Integrated_Circuits&diff=3886Integrated Circuits2007-05-24T02:16:31Z<p>RogerAF: /* Voltage Regulators */</p>
<hr />
<div>== Digital Potentiometers ==<br />
[[Digital Potentiometers|Digital Potentiometers(AD5204)]]<br />
The digital Potentiometers made by analog devices (AD5204) has 255 positions can be adjusted by the microcomputer that can receive commands from the computer. This is a great way for analog circuitry to have digital control. This is a chip with 4 digitally controlled POTs and the pots can be daisy chained to have multiple chips controled by a single SPI interface.<br />
<br />
<br />
<br />
== Voltage Regulators ==<br />
{|<br />
! colspan="2" align="left"| Linear Regulators<br />
|-<br />
| align="center"|[[Image:Main-LT1528.jpg|69px|LT1528]]<br>[[LT1528]]<br />
| High current, Variable Voltage Regulator<br />
|-<br />
| align="center"|[[Image:TPS-V-Reg.jpg|69px|TPS V-Reg]]<br>[[TPS V-Regs]]<br />
| These are 3.3V and 5V LDO, Low-Noise Voltage Regulators. Very small SOT-23 SMD package. 150mA max current. Best used in battery applications.<br />
|-<br />
| align="center"|[[Image:Main-LM7805.jpg|69px]]<br>[[Basic Voltage Regulators]]<br />
| Variable voltage regulators, set output regulators, we give you the whole breakdown. Perfect for use with an external wall-wart power supply.<br />
|-<br />
| align="center"| [[Image:UA723CN_Symbol.gif]]<br>[[The 723 - DIP-14]]<br>[[The 723 Voltage Regulator]]<br />
| Precision Voltage Regulator. Very flexable. Can be used as anchored or floating, fixed or variable, linear or switching, and in verious combinations of the above.<br />
|-<br />
| &nbsp;<br />
|-<br />
! colspan="2" align="left"| Switching Regulators<br />
|-<br />
| align="center"| [[Image:MCP1253-ADJ.png|69px]]<br>[[MCP1252/3]]<br />
| Extremely Efficient, 120mA Flyback Switching Regulators.<br />
|-<br />
|}<br />
<br />
== Microcontrollers ==<br />
<br />
* [[Image:lpc2103.jpg|69px|LPC2103]] [http://www.k9spud.com/arm/lpc2103/ LPC2103] Low cost 70MHz ARM7TDMI-S FLASH Microcontroller from Philips. The [http://coridiumcorp.com/arm7/ "$49" "Coridium ARMmite"] does use this chip.<br />
* [[Atmel]] AVR 8 bit FLASH microcontrollers<br />
* [[Microchip]] PIC 8 bit FLASH microcontrollers<br />
* Microchip dsPIC 16 bit FLASH microcontrollers ( [[DsPIC30F 5011 Development Board]] )<br />
* Cypress PSoC 8 bit FLASH microcontrollers<br />
<br />
''I've written a little about the various kinds of microcontrollers at [http://en.wikibooks.org/wiki/Embedded_Systems/Particular_Microprocessors Wikibooks: Embedded Systems]. --[[User:DavidCary|DavidCary]] 06:15, 10 March 2007 (PST)''<br />
<br />
== Op Amps ==<br />
<br />
Op amps and instrumentation amps.<br />
<br />
[[op amp]]s: great for amplifying weak signals from [[sensors]] to a more useful level. Also used in filters, integrators, etc. <br />
<br />
* [[LT1168|LT1168 Programmable-Gain Precision Instrumentation Amplifier]] - Low Power, Single Resistor Gain Programmable, Precision Instrumentation Amplifier<br />
* [[LT1114|LT1114 Low Power Precision OP-Amps]] are used for amplification and filtering of the signal - Dual/Quad Low Power Precision, Picoamp Input Op Amps<br />
<br />
* [http://en.wikibooks.org/wiki/Electronics/Op-Amps Wikibooks:Op-Amps] has a "quick design process" using Daisy's theorem: ''"The sum of the gains = +1 in a properly-designed op amp circuit."''<br />
<br />
* [http://ciphersbyritter.com/RADELECT/PREOPAMP/OPAMPDSN.HTM "Some Op Amp Audio Design Issues"] by Terry Ritter<br />
<br />
== logic gates ==<br />
<br />
* NAND gate: [http://www.coprolite.com/art48.html "Using a NAND Gate for a Set/Reset Latch"] (the 74HC132 Schmitt-trigger quad NAND is better than the 74HC00 quad NAND).<br />
* [http://people.freenet.de/dieter.02/alu_4.htm "Multiplexers: the tactical Nuke of Logic Design"] by Dieter Mueller 2004 (74153)<br />
<br />
There are hundreds of other specialized logic gates. Here we only list the ones we actually use in some Open Circuit [[Projects|Project]]:<br />
<br />
* 74HC595 eight bit shift register with output latch (used for POV display)<br />
<br />
[[Category:Components]]</div>RogerAFhttp://www.opencircuits.com/index.php?title=User:RogerAF&diff=3885User:RogerAF2007-05-24T02:14:06Z<p>RogerAF: </p>
<hr />
<div>'''Introduction'''<br />
<br />
Aloha from Honolulu,<br />
I found Open Circuits on or about May 15, 2007. I was searching the internet for "electronic breadboard" and found SparkFun Electronics which has a link to Open Circuits.<br />
<br />
I have an idea for some "building block" circuit boards that engineers and students can use for breadboarding. I just happen to need something like this myself, so maybe others can use them too. I couldn't find anything like I have in mind, so perhaps there is a market waitng to be created. I'd be happy to share the scematics and artwork (once they exist) and hope that others will share their ideas. Eventualy we could build a library of these that colleges and tech schools would use.<br />
<br />
So that is how I came to Open Circuits. It also happened to be at a time when I had just completed a project that had been hanging fire for several years. That is the artwork for some voltage regulator boards based on the LM723 IC. I have used these in several personal projects and also in some professional ones.<br />
<br />
My main gig here in Honolulu has been the installation and servicing of recording studios. I've been at it for the past 20 years. I had one client whose console power supply needed help. The voltage regulators were a high current (7 amp) device in a TO3 package. There was one each for the +15V and -15V rails. I'd replaced them once before, but this time I could not find the devices. (I forgot what the part number was.) So I decided to use a couple of LM723s which I had a large supply of (courtesy of another project that had not gotten off the ground). I used a 2N3055 transistor as the external series pass element for the positive side and tried to use its compliment 2N2955 for the negative side. But I found I could not get the current required. I switched to a Darlington device and the problem went away, so I used a complimentary pair of 15 amp Darlington transistors in TO3 packages. The unit has now been working for nearly 10 years. I plan to share these designs here once I have a better understanding of how to upload files and what formats to use.<br />
<br />
My other interests are in embedded processors and computer programming. I used to do a lot with Pascal and Assembly back in the DOS days. I started with Turbo Pascal 3 and Turbo Assembler, I went up to Turbo Pascal version 7 before Windows came along and made it more complicated. I started to learn C++, but got out of programming for several years. I got back into it again when embedded devices started to proliferate. I brushed off my C++, but find I'm mostly using plain C with these things. That and Assembly when something needs to go as fast as it can.<br />
<br />
I'll continue with this as time allows.<br />
<br />
Aloha,<br />
Roger<br />
[[User:RogerAF|RAF]] 17:45, 18 May 2007 (PDT)<br />
<br />
Hello again,<br />
I fiished my article as well as another article I want to include. The second is not mine, but is so old I can't find it anywhere, but for the copy I have in my files. The title is: "The Many-Talented 723" and the author is Glenn Prescott. I've searched the web without finding any reference to it. I have a xerox copy from the mid 1980s. Not a very good copy, but I scanned it and ran an OCR program on it. I still had to do a lot of editing to help out the OCR. Then I had to do all the images over again myself. I kept them as close to the originals as I could, except for scale, mine are a little larger and this more legible. My text is also full page instead of the 4 column format of the original. So now I'm ready to put this all together. I uploaded a symbol for the image of the 723. Otherwise it would be a picture of a 14-pin DIP. I'm going to see if I can copy it to this page...<br />
<br />
[[Image:UA723CN_Symbol.gif]]<br />
<br />
OK, that wasn't too bad, except for forgetting what the name was...<br />
Now let's see about the Component article.<br />
[[User:RogerAF|RAF]]<br />
<br />
<br />
Well, I had to write the question to David Cary. I couldn't figure out how to make a stand-alone article for the 723. What I did was put it in the "discussion page for the image file. That is just a temporary solution and there isn't any room for my in-depth text on using the 723 anfd Glenn Prescott's article "The Many-Talented 723". Hopefully David can show me how to make it happen and all will be well...<br />
<br />
<br />
I figured out how to post a new article. I searched for "New Article" and of course the search returned with "no such thing found", but it has "thing" in red. Aha! it is an internal link. Click on it and it takes you to another page that says basically "Hi this is not the page of "thing" because "thing" does not exist. If you would like to create "thing" click on the edit button. So I did and was able to copy/paste my article and save it.<br />
<br />
For anyone who was ho;ding their breath waiting for my promised articles, here is a link to the first:<br />
<br />
[[The 723 Voltage Regulator]]<br />
<br />
You may have to hold on a bit longer while I get the second ready (it has several images that need to be placed along with the text).<br />
<br />
[[User:RogerAF|RAF]] 19:14, 23 May 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=My_Experience_With_The_723&diff=3884My Experience With The 7232007-05-24T02:04:54Z<p>RogerAF: </p>
<hr />
<div>== My Experience With the 723 Voltage Regulator IC ==<br />
<br />
'''Introduction:'''<br />
<br />
I came across the LM723 in the 1980s and thought it was much too complicated to use. I liked the 3-terminal regulators and stayed with them until I had to make a power supply that would handle more current than they could supply. In the mid ‘80s I’d come across a copy of an article called “The Many Talented 723" by Glen Prescott. I don’t know where this was published and I’ve been unable to locate it through Google. However I still have my copy and I decided it was worth scanning and cleaning up the figures, so I can share it with the world.<br />
<br />
There are a couple of companies who make the device, that describe it in their data sheet titles as a “Precision Voltage Regulator”. This is what it is. If you were to design a voltage regulator from scratch, using discrete components. You’d want to end up with something like the 723. I’m not going to go into detail about it, because the data sheets and Mr. Prescott’s article do that very well already. I just want to share some of my experiences in the use of it.<br />
<br />
<br />
'''My First Mixer Power Supply:'''<br />
<br />
I built a little microphone mixer while I was in electronics school and I needed a power supply for it. I had a pair of LM723 ICs in a drawer, but I’d never worked with the chip. I decided that I should learn about it. The National Semiconductor Linear data book showed a lot of different ways to use it and decided to build a plus and minus 15 volt supply with external pass devices. I included trimmers for fine tuning the outputs and I had a little aluminum case that I could fit the transformer, rectifier, filter capacitors, and PC board into. I used a sharpie pen and drew the layout by hand except for the IC patterns. I etched the board and assembled it. It powered my mixer very nicely and I got an A in that class.<br />
<br />
Last year I started experimenting with an Analog Devices AD7329–a 13-bit, 8 channel A to D converter which requires ±15V as well as 5V supplies. I dusted my little power supply off (it is over 20 years old now) tuned it on and checked the outputs. I thought I’d probably need to adjust the trimmers some, but even after sitting for the last 20 years, it was measuring +14.998V and -15.01V. I was very impressed and decided it was too nice to leave in a box. So it is out of retirement and I use it for my experiments on my bench whenever I’m working with op-amps that need ±15V.<br />
<br />
<br />
'''Second Mixer Power Supply:'''<br />
<br />
I service several recording studios here in Honolulu. One of my clients has a console whose power supply failed. It had failed before and I’d replaced the regulators, which were high current (7 amps) devices in TO3 packages. But the last time it failed I could not find replacements. I’ve forgotten the part number of the device, but it does not seem to be made any more and no one has produced a substitute.<br />
<br />
My client was understandably upset. Recording studios need to have working equipment–especially the mixing console. I told him I’d need at least 48 hours if not 72 to build replacement regulators. He said to hurry.<br />
<br />
I used the same circuit as in my little mixer supply above. I hand wired it on pad-per-hole perfboard and had the regulator cards complete in 30 hours. I got the positive regulator working with a 2N3055 transistor as the NPN series pass device. But when I tried to use the PNP compliment–2N2955 transistor, I could not get it to produce 15V at 7 amps. I finally figured out that the chip, since it uses the Vz pin in the negative configuration, just doesn’t have the same drive capability as it does when using the output pin in the positive configuration.<br />
<br />
The clock was ticking and I was sweating, when I thought of trying a Darlington transistor. I had just purchased some a few days before, so I had them on hand, at midnight with no parts stores open. That proved to be the solution and so I switched the 2N3055 on the positive side for the NPN Darlington compliment of the transistor I had on the negative side. The devices are sold as a complimentary pair at a couple of local electronics stores. This was one of my design objectives, so in case of emergency, the parts are available locally.<br />
<br />
The TO3 packages of the external series pass transistors went into the same holes on the heat-sink as the original regulators. A couple of stand-offs support the cards with the 723s. I connected the regulator inputs to the filter caps and the transistor outputs to the fuses, and the studio was back in business.<br />
<br />
<br />
'''Current Limiting:'''<br />
<br />
The 723 has built in current limiting, but it is designed as a positive regulator. So there is no provision for current limiting in a negative configuration. Also current limiting is dependent on a resistor which must handle the maximum current the regulator is designed to supply. In the case of large currents >1 amp, this produces significant heat. I left the current limiting out of my designs. I didn’t want to have only the positive half of the supply getting limited while the negative half operated with no limit. I reasoned that since the supply outputs were fused, there was already protection in place.<br />
<br />
This is the case with all the regulator designs I present here. If you need current limiting and you just need a positive regulator, the 723 can easily accommodate you. Just figure out how much current you need to supply and how much over that you’re willing to tolerate, then calculate ILimit = Vsense / RSC.<br />
<br />
The regulator is also capable of foldback current limiting where there is a “knee” region before full shutdown occurs. Personally I have never used the current limiting features, so I cannot write from experience. If the supply is to be used in an application where shorting or over currents are possible, I use fuses.<br />
<br />
<br />
'''Low Voltage Supply:'''<br />
<br />
When I began experimenting with embedded processors, I found that many needed supplies in the 3V to 4V range. By this time I had become fairly adept at using the 723 and since I had some still, I decided to use one, rather than investing in a fixed low voltage regulator. I went with a positive output using an external PNP transistor. Again, I added a trimmer pot, so I can adjust from around 2.75V to 4.25V. This little board (the transistor has a TO92 package) measures only 1" x 2" and has a power on LED indicator, and two–2-pole screw terminal blocks. It has been very handy.<br />
<br />
<br />
'''“Big Bertha” Bench Supply:'''<br />
<br />
In the world of professional audio, the Jensen 990 discrete opamp is a famous classic. Designed to work with ±24V power supplies, it is considered the “holy grail” of opamp designs. I have worked on MCI’s JH500 series consoles which have ±36V power supply rails–they use a high voltage opamp like the TI OPA544 and add a NPN/PNP output buffer to each. The whole console is filled with these–talk about an air conditioning bill. But having these high voltage rails means the audio signal can reach large levels of voltage swing and go onto the tape as hot as you can stand it. Of course this is analog. With digital there is no need for this. But there are audio people who prefer analog, and a high voltage opamp can add to the sound of the console.<br />
<br />
I have another client who records to digital media, but mixes on an analog console. He had me modify the console master stage with discrete opamps running on their own separate ±24V power supply. He felt that it made the mixes sound better. I can’t say for sure, I was not exposed to listening to it every day, but I have no reason to doubt it. He gets a lot of work coming into his studio.<br />
<br />
But the story here is about “Big Bertha”. I decided I want to design a modern version of the Jensen 990 and I might as well make it able to operate at ±36V. To do this effectively I needed a suitable power supply. I built one using two 36V transformers in series. I regulated it with a pair of 723s and 20A Darlington transistors. I don’t plan on drawing anywhere near that amount of current, I just had them on hand. In fact everything I used to build “Big Bertha” was residing in drawers and boxes at my shop. (One of the design goals was to make it without spending any money.)<br />
<br />
Actually the unregulated supply is around ±56V. This is beyond the 723's input voltage limit. I could have made floating regulators (more on those later), but I decided to try “amplified zeners” instead. I came across the “amplified zener” in “The Power Supply Handbook” by the editors of 73 magazine. I’ve used it over the years, when I’d get stuck for a solution. It has several clever ideas that have proved very useful, the amplified zener being one of them. Basically you take a zener diode and a transistor and connect them so the zener’s cathode is at the transistor base, and the transistor collector is the zener’s anode. No resistor needed as long as you avoid the knee region of the zener. I used this trick to knock the unregulated supply down to around ±38V (the 723 max input is 40V). I have these squarish heat sinks that can hold TO3 devices and I stacked 4 of them together; 2 on top of 2, so my amplified zeners and the Darlington pass devices are contained in an area that is the perfect size for a 5" fan, should I ever need to draw so much current that things get warm. So far that hasn’t happened. I can adjust the output from around 12V to just over 30V. I know it isn’t up to the ±36V of the MCI JH500, but I decided that wasn’t really needed. If someone wants an op amp to handle that, I’ll use the OPA544.<br />
<br />
I haven’t really had a chance to put “Big Bertha” to the test. Mostly I’ve used her to power breadboard circuits at around ±18V. This is what Amek and SSL consoles operate at and those are what my remaining clients have. The computer revolution put most of the recording studios in Honolulu out of business.<br />
<br />
Still, I like the idea of having a supply that can give me that kind of voltage range with a rock solid regulation that doesn’t drift or sag.<br />
<br />
<br />
'''Closing Thoughts:'''<br />
<br />
The 723 is a versatile voltage regulator. According to National Semiconductor’s data sheet: “The LM723/LM723C is also useful in a wide range of other applications such as a shunt regulator, a current regulator or a temperature controller.” And “Can be used as either a linear or a switching regulator”.<br />
<br />
I have only used it as a linear series regulator and I’ve been pleased with the results. I have just started experimenting with switching regulators. I built my first one with a TL494 PWM controller. I will probably try out the 723 in that mode of operation when I have some time on my hands and no other projects waiting. But that may be a while, so if anyone has actually done it, I’d appreciate it if you’d share the info.<br />
<br />
I hope this article is useful and I welcome comments and ideas.<br />
<br />
[[User:RogerAF|RAF]] 19:04, 23 May 2007 (PDT)</div>RogerAFhttp://www.opencircuits.com/index.php?title=File:UA723CN_Symbol.gif&diff=3883File:UA723CN Symbol.gif2007-05-24T01:55:46Z<p>RogerAF: </p>
<hr />
<div>[[The 723 Voltage Regulator]]<br />
Precision Voltage Regulator. Can be used as fixed or floating, variable, linear or switching. '''NOTE:''' Only the DIP-14 version has the Vz pin, which is used for negative regulators. The Metal Can and the Flat-Pack do not have enough pins so exclude the Vz.</div>RogerAFhttp://www.opencircuits.com/index.php?title=The_723_Voltage_Regulator&diff=3881The 723 Voltage Regulator2007-05-24T01:51:59Z<p>RogerAF: Image talk:UA723CN Symbol.gif moved to The 723 Voltage Regulator</p>
<hr />
<div>== The 723 Voltage Regulator ==<br />
[[Image:UA723CN_Symbol.gif]]<br />
<br />
'''Description:'''<br />
<br />
The 723 is ancient in the world of IC voltage regulators. It is a 14-pin IC that needs some outboard components to tell it what to do. By itself it isn’t that impressive with a current capacity of 150mA, but with the addition of an external series pass transistor it can control whatever current the transistor can handle. It is designed primarily to be used as a positive regulator, but it can also be made to function as a negative regulator. In addition, although it is rated to 37 volts, it can be used in a “floating” mode and regulate voltages above that limit. All in all, I’ve found it to be a very stable, precise, and versatile device.<br />
<br />
The main IC: LM723 is specified at temperatures from -55°C to +125°C. This chip is a little harder to find, and is more expensive than the LM723C which is exactly the same (as far as I know) but for the temperature spec which is from 0°C to +70°C.<br />
<br />
I’m including two other documents about the IC: “The Many Talented 723" by Glen Prescott was my introduction to using it. “My Experience of the 723 Voltage Regulator IC” by Roger Furer is my own story of the different regulator circuits I’ve built with it and includes links to schematics and PC Board layouts.<br />
<br />
'''Documents:'''<br />
<br />
Several companies manufacture the LM723, but the data sheets are pretty much the same.<br />
<br />
Texas Instruments calls it the µA723:<br />
[http://focus.ti.com/lit/ds/symlink/ua723.pdf]<br />
<br />
National Semiconductor calls it the LM723 and LM723C (reduced temperature version)<br />
[http://cache.national.com/ds/LM/LM723.pdf]<br />
<br />
On Semiconductor never heard of it, but ST Microelectronics makes the LM723 (with various suffixes)<br />
[http://www.st.com/stonline/products/literature/ds/4553/lm723.pdf]<br />
<br />
'''Footprints:'''<br />
<br />
It is available as a 14-pin DIP from everyone. In a metal can: H10C from National, and as an SO-14 from STM and TI. There may be other packages available from other manufacturers, but I limited my search to these three. Note that only the DIP-14 package has the Vz pin--the output from the zener diode which is used for negative regulators. The metal can and the flat-pack do not have enough pins and so they skip this one.<br />
<br />
'''Manufacturer Info:'''<br />
<br />
'''Note: '''<br />
The LM723C is identical to the LM723 except that the LM723C has its performance guaranteed over a 0̊C to +70̊C temperature range, instead of −55̊C to +125̊C.<br />
<br />
<br />
National Semiconductor part # :<br />
<br />
LM723H, LM723H/883, or LM723CH : Metal Can Package (H), NS Package H10C<br />
<br />
LM723J/883 : Ceramic Dual-In-Line Package (J), NS Package J14A<br />
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LM723CN : Molded Dual-In-Line Package (N), NS Package N14A<br />
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<br />
ST Microelectronics part # :<br />
<br />
LM723N : DIP-14<br />
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LM723CN : DIP-14<br />
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LM723CD : SO-14<br />
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<br />
Texas Instruments part # :<br />
<br />
µA723CN : Plastic DIP (N),<br />
<br />
µA723CD : Small Outline (D)<br />
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<br />
NTE makes a substitute: NTE923<br />
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'''Supplier Info:'''<br />
<br />
'''Jameco'''<br />
<br />
Major Brands<br />
<br />
LM723CN, DIP-14, Jameco part# : 24467, price: 1+ 0.34<br />
<br />
LM723H, TO-5, Jameco part# : 301719, price: 1+ 3.69<br />
<br />
Texas Instruments<br />
<br />
UA723CDE4 Jameco part# : 1129851, price: 50+ 0.319<br />
<br />
UA723CNE4 Jameco part# : 1129914, price: 1000+ 0.295<br />
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<br />
National Semiconductor<br />
<br />
LM723CN/NOPB Jameco part# : 840691, price: 10+ 0.482<br />
<br />
<br />
<br />
'''Mouser'''<br />
<br />
Fairchild Semiconductor<br />
<br />
KA723, DIP-14 Mouser part# : 512-KA723, price: 1+ .67<br />
<br />
KA723DTF, SOP-14 Mouser part# : 512-KA723DTF, price: 1+ .67<br />
<br />
<br />
ST Microelectronics<br />
<br />
LM723CD, SO-14 Mouser part# : 511-LM723CD, price: 1+ .38<br />
<br />
LM723CN, DIP-14 Mouser part# : 511-LM723CN, price: 1+ .32<br />
<br />
LM723N, DIP-14 Mouser part# : 511-LM723N, price: 1+ .64<br />
<br />
Texas Instruments<br />
UA723CN, DIP-14 Mouser part# : 595-UA723CN, price: 1+ .53<br />
<br />
<br />
'''Digikey'''<br />
<br />
National Semiconductor<br />
<br />
LM723CH/NOPB, TO-5 Digikey part # : LM723CH-ND, price: 1+ 5.48<br />
<br />
LM723H, TO-5 Digikey part # : LM723H-ND, price: 1+ 5.48<br />
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LM723CN/NOPB, DIP-14 Digikey part # : LM723CNNS-ND, price: 1+ 1.12<br />
<br />
<br />
ST Microelectronics<br />
<br />
LM723N, DIP-14 Digikey part # : 497-4268-5-ND, price: 1+ 0.99<br />
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LM723CD, 14-SOIC Digikey part # : 497-1595-5-ND, price: 1+ 0.86<br />
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<br />
there are more, but you get the idea.</div>RogerAFhttp://www.opencircuits.com/index.php?title=File_talk:UA723CN_Symbol.gif&diff=3882File talk:UA723CN Symbol.gif2007-05-24T01:51:59Z<p>RogerAF: Image talk:UA723CN Symbol.gif moved to The 723 Voltage Regulator</p>
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<div>#redirect [[The 723 Voltage Regulator]]</div>RogerAFhttp://www.opencircuits.com/index.php?title=File:UA723CN_Symbol.gif&diff=3880File:UA723CN Symbol.gif2007-05-24T01:50:57Z<p>RogerAF: </p>
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<div>Precision Voltage Regulator. Can be used as fixed or floating, variable, linear or switching. '''NOTE:''' Only the DIP-14 version has the Vz pin, which is used for negative regulators. The Metal Can and the Flat-Pack do not have enough pins so exclude the Vz.</div>RogerAF