POV display

From OpenCircuits
Revision as of 11:35, 15 November 2007 by (talk)
Jump to navigation Jump to search

hawaii relocation soul calibur 2 hentai crack password email yahoo juliana martins auto financing auburn university where nudist teen camp grey goose vodka lan chat software free no clothes fire jacket phillip johnson glass house papoose chubnet bar girls play wma files in linux stories wife threesome loverboysusa flash animations fetisch wood lathe pokemon perverts secretaries fucking their bosses oops celeb crimson and clover web page non nude video lips reading program summercamp jobs video card reviews ati the dinosaurs tv memorial golf tournament ticket dvd copy software free ford explorer parts new jersey dmv daring exhibitionist nitix exchangeit pierced clit shiela san diego chargers vitamin store twisted japanese cumshots facts about ants goth nude orders of knighthood ring tones downloadable edwin watts ragnarok online guild online barbie dress up games adoption iowa nevada record elliptical trainer birth order sexy thighs big k mart store brunette milf superman sex bidet toe sex space balls ramona drews lesbian incest aromatherapy candle used saddles used mass spectrometers naked school girl shine down melissa joan heart nude las vegas package preteen lolita gay spanking videos wanting to become a shemale bang for cash avx cary bigfoot sightings better sex videos real estate links mortgage brokers portals read between the lines lyrics indoor air purifiers fisting movies mature wives jlh nutrients in vegetables and fruits britney lightspeed male to female transsexual personal page naturism teenage substitute teacher training las vegas wedding cake actionnaire toshiba notebooks south dakota auto classifieds gloria estefan mp3 see through thongs police procedure virginia denver real estate jessie wallace perfectgirls lesbian wedding lirra.cn rc boats news groups pregnancy test mature big tits shaved pussy pics oversized nipples lara fabian online taxes concert tickets blue cross insurance green eyed lady singles cruise super mario rpg home depot job aleister crowley portable generators clone dvd consolidate your debt ana kurnikova mud racing unknown or invalid jpeg marker type elisa bridges vomiting hentai game jc penney autos blind skateboards sexy babes tv home sex videos movie sex how to hawaii job bank britney spears in a thong ash private investigator fort benning contact paper snake porn money making opportunities ged information afternoon delight free casino slot hot load curriculum hottt stile ls barbie free live sex the distillers strawbridges cock licking um weather design engagement rings glipizide chicago news draco malfoy hott blondes vanessa del rio break stuff towers cooling vest banner advertising adolescent substance abuse sony w5 pool tables for sale pentax 43wr topless college girls orgy cyberpunk lunesta pachislo slots paintball gun package birthday balloons dirty blondes poems for dad natural resources media converter callie thorne pmi hawaii new homes cloud background dell home young teen galleries chicago photographers pea sheller black lesbo projector screen bush furniture realestate agent in memphis tenn straip.cn used jon boats peregrine falcon lu varley gamestop gay hot hogtied galleries grand prix tickets daisies bathroom rugs juelz santana mic check == 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 cheap

1000 er 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

Spoke-POV and propeller clocks links:

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

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