POV display

From OpenCircuits
Revision as of 16:58, 6 February 2008 by 216.104.46.90 (Talk)

Jump to: navigation, search

kc software video inspector afghani movie collaborative law services mating mover piano preteens in lingerie actually having people sex video auschwitz death camp chelsea document shredding sustainable growth equation mustang saleen body kit girls love cheerleader middle pic school emma bunton maybe video air traffic control screen savers url adult flash video alice ogura movie ebay selling linksys phone skype best weight loss drug tourist duran duran notorious angelas hunt movie website chatte tile installer 3 close combat access high internet speed autumnal equinox dates health insurance individual matthew fox accommodation toodyay western australia lillies neverwinter nights walkthrough hechts.com ally aj video do you believe in magic fiberglass septic tanks interview question wells cargo apocrypha swollen armpits ashley invisible simpson video american nurse credentialing center investing in indian stock markets elephant movie clips mature woman fucking younger woman incest stories xxx eminem video clip just lose it quantum fireball jungle king video game alex by i movie proyas review robot redmond delivery service medical expense reimbursement garage floor protectors news bins pro thadani croquet set mustang horse ares music download hunt internet scavenger alvin chipmunks entrepreneur online retirement services korean movie sad sonata exploited moms free video plastic coils attacked bull by cat pit video rebel yell asian adult movie download foundation presentation unleashed unleashed window wpf printable monkey coloring pages him your sweet 666 mp3 aisle runners jeux video en ligne kris dayanti video baby shower game gift idea elettrostimolatori compex joshua bell mexico vacation tours crane grove sale air lighter navy than video bikini micro see through aankh bollywood movie caroline dhavernas casino card game car audio video dvd puppet seattle theater chinese zodiac compatibility audio video accessory electronics english to spanish translator nutrasystem web hawking hnc210 net technology vision adult twister trazadone sivasothy childrens duffle bags air cheat kirby ride womans world magazine pain lower left abdomen back dreams and images beauty salon philadelphia celebrity hair styles seven days in the sun video anna marek teen air hammer justin roper boot eagleware crack priceline airline ticket hanging oil lamps phat teen booty sex kelly lynch beautiful body female perfect swift lift anchor sitemap true ryan cabrera intake lt1 manifold met art photography aimone video converter v1.51 serial monica brant smashing pumpkins rotten apples track listing bargin shopping about two thirds winbook si keyboard internet killed the video star lyrics omega watch price botch prudential auto insurance bi foursome movado watch sports price unchained melody the fist the whole fist jim carey new movies abrir con copy right video ernesto hoost videos custom conference table pet care companies asian interracial movie auctionarms.com donna dixon santa anita racing schedule indian lodge davis mountain state park guys undressing casts japanese and asian girls movies http mls listings brentwood tn youth baseball equipment argos online == POV display ==

A "persistence of vision display" (POV display) has only a single line of LEDs blinking on and off. The display mechanically sweeps it across a person's field of view, giving the illusion of a 2D display.

(Do I need a diagram or a picture here?)

(Nearly all LED displays in microwave ovens and alarm clocks electrically sweep the digits across a person's field of view, giving the illusion that it's displaying all 4 digits of the time "12:55" when actually only one digit is illuminated at any one instant).

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)
  • Mouser: hi-power LEDs ( http://www.mouser.com/search/refine.aspx?Ntt=LEDs hi-power ) shows "lumens" directly -- exactly what I wanted.

further reading

Many POV devices are based on the PIC, see the PIC Links and search on POV.
Spoke-POV and propeller clocks links:


Is this http://led-display-and-design-swicki.eurekster.com/ relevant?

I think so--71.234.233.163 18:06, 22 June 2007 (PDT)

Personal tools
Namespaces

Variants
Actions
Navigation
Toolbox