meridia wwe ringtones phentermine online cheap xanax cheap hydrocodone zanaflex online free ringtones didrex online free real ringtones buy fioricet buy diazepam rivotril online ativan online sonyericsson ringtones sagem ringtones free verizon ringtones sharp ringtones cheap ortho wellbutrin online valium online cheap nexium free tracfone ringtones sony ericsson ringtones free cool ringtones but zoloft free motorola ringtones free qwest ringtones samsung ringtones nextel ringtones cheap celexa free ericsson ringtones free midi ringtones cheap tenuate levitra online cheap adipex punk ringtones propecia online cheap albuterol alprazolam online buy viagra tramadol online sony ringtones ambien online free funny ringtones cheap hgh free polyphonic ringtones cheap cialis nokia ringtones but flexeril norco ultracet online carisoprodol online kyocera ringtones cheap clonazepam pharmacy online online cheap cyclobenzaprine cheap ultram order lisinopril cheap xenical cheap zyban free mono ringtones buy lorazepam sprint ringtones cheap lipitor prozac online free music ringtones cheap hoodia vigrx online diethylpropion online but lortab vicodin online free mtv ringtones alltel ringtones cheap soma free jazz ringtones sildenafil online paxil online mp3 ringtones clomid online free cingular ringtones == POV display ==
User:DavidCary is building yet another "POV display".
I plan on putting a few features into my display that I haven't seen in any other so far:
- bright blue LEDs (even though blue is usually the most expensive color ... although sometimes "true green" is even more expensive than blue).
- no slip rings -- just pumping energy across an air gap
- ... and a few other features that I'm keeping hush-hush.
I want lots of lumens. Unfortunately, when I go to pick LEDs out of the catalogs, they're not rated in lumens, they're rated in candelas.
Is it even possible to estimate "lumens" from the catalog information?
Do you know what the difference is? Does your flashlight really produce 10 times the light ( in lumens)? Or does the flashlight merely focus its light on a tiny spot, so that that spot gets 10 times as many candelas ?
For example, check out these 2 LEDs: $8.75 SSP-LX6144C7UC : 4000 mcd at 120 mA $8.75 SSP-LX6144D7UC : 1800 mcd at 120 mA
From the mcd rating, it appears that the first one is more than 2wice as bright -- and it is, if you're directly in front of it when you look at it. However, if you're even the tiniest bit off-center, the second one is much brighter -- in fact, the total lumens that second LED puts out (2500 mlm) is slightly more than the total lumens than the first one. If you diffuse the light and try to light up a whole room with an array of them, the second one will make the room brighter.
I'm currently planning on using these in my first POV display:
- $1.32 Telux TLWB7900 : blue : 330 mlm, 231 mcd at 50 mA. (price in ones from http://Newark.com/ )
Other LEDs I considered using in my POV display (and may re-consider for my next one):
- $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).
- $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"
- $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).
- $1.600 Sunbrite "based LED" SSP-01TWB7UWB12 (441-1007-ND) blue 10 mm 20 mA 7000 mcd
- $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)
Spoke-POV and propeller clocks links:
- An entire discussion forum devoted to POV displays http://www.ladyada.net.nyud.net:8090/forums/viewforum.php?f=11
- In particular, lots of nice pictures http://www.ladyada.net.nyud.net:8090/forums/viewtopic.php?p=4712
- 'no-microcontroller-programmer-needed' minipov http://www.ladyada.net.nyud.net:8090/forums/viewtopic.php?t=32
- LEDtoy on Sourceforge http://ledtoy.sourceforge.net/
- Ian’s Spoke POV http://www.ianpaterson.org/projects/spokepov20050704/index.htm
- "Propeller Clock" Mechanically Scanned LED Clock: by Bob Blick http://www.bobblick.com/techref/projects/propclock/propclock.html (I think this is the original)
- micro POV display http://positron.org/projects/mpov/ small enough for "glueing it to my shaved head."
Is this http://led-display-and-design-swicki.eurekster.com/ relevant?
I think so--126.96.36.199 18:06, 22 June 2007 (PDT)