POV display

From OpenCircuits
Revision as of 13:31, 18 November 2007 by 38.117.88.72 (talk)
Jump to navigation Jump to search

interface parameter tcpip achat maison quebec man treat printer refill ink angry kid download to mobile star sp 200 drivers veterinary medicine careers picture pomegranates king juan carlos i of spain spirituality practice microsoft anti virus free downloads maryland job finder arkansas department human resource schroders london myspace.com site tete special education law cases the music of buffy the vampire slayer to beat the child was bad enough auto gps review system window steam cleaners active control flow gas turbine musical note gifs space news daily memphis commercial real estate 6 tbsp one safe place media corp animal insurance a sentimental mood salary of radiologist aims science and math illinois nursing home litigation new broad street normalize sound sec football coaches lcd displays mac secured transactions outline arthur a levine books pediatricians in illinois public usenet news servers i want to look at some bathroom interior designs lol lol lol lol las vegas downtown casinos the city of industry rating spot massage chicago male the good life tab post mortem game hints equipment joe johnson walt disney world collectible abbeys kids printable calendars jimi henrix lyrics aim buddy block virginia car registration luggage dealers legal statute of limitations tv capture software free pool fun underwater linh kien vi tinh 13th birthday quote annie casey e foundation shabby chic baby sheets 9 11 pentagon coverup amd 64 754 map pokemon ruby machine safety vending north american mountains show me all games amino acid deficiency symptoms online graphing calculator free master esl on line program shared memory service not created yet making lollipops mount saint joes college light deflection afterhours 2 picadilly theatre london msn messenger emotions lab animals low cost hotels new york auto discount rental vancouver search imageshack us womens postal service uniform 3d computer animation courses iceberg records austin real estate values snatch video game maps bicycle elvis listen presley song oak acorn what is qcd smiths album covers european cycling holidays mega mart rare african animals ultimate resource guide zip codes in pa evening dress shops uk apparatus theory meth production by state aloud book grader read second which broadband pinay big rummy luxury condominium floor plans indian college ratings rerio austin randalls texas the betsy the movie j lazar you shine christian lyrics job openings for wisconsin away message sayings as de el la lyric sierra 1974 touch wind online program rn new operating systems material services supreme court justice vote most popular keyword search underground in atlanta ga quality data management arthur a levine books post mortem game hints smoothest riding network printing linux estate houston industrial real nascar baby toys riviera las vegas review shoes cheap in hiragana rally pc games name days greece sand art projects planet star war picture of people in the holocaust a man holding onto a woman letting go pictures of tattoos on top of feet recent sales real estate in from the storm play free car racing game now log site web web self reliance lesson ashley williams gallery watch a movie on line music cd label new king james version of the bible market listing service pictures of plant cells masturbation pics monster cock farm marine electronics jobs 2006 by draft nfl team the council house birmingham perm status kids bedroom photos shell plant farm webcam motion detection legal statute of limitations products liability outline mens medium hair styles public boarding school underwriter salary sprint email sms merrick company star symbol keyboard zoom text opportunity posters nokia 9210 softwares microsoft cluster service 2003 256mb sodimm sdram what was the final solution new london ct weather muscles in the knee air india contact no the swarm and i love you came too late lyrics ac drive theory mobile n73 nokia phone thermocouple applications panasonic x200 paul clements a road less traveled by adobe 4.0 downloads austin real world air mustang ram axe handles second life last names natural remedies for arthritis pain pole dancing schools long beach wa cabin orange county ny health department america home cooking cook book andrew car texas used maker poll software example of resume cover letter autocad training centers liberal party leadership candidates wv counties map telegraph calcutta == 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 blu

1000 e 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

1000 

camera flash ?) (Digikey)

further reading

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)

Retrieved from "http://www.opencircuits.com/index.php?title=POV_display&oldid=11154"