POV display

asian anal italian road bicycles anti virus free ware resume service school of dental in hawaii no more dead dogs book female feet bastinado american river junior college metaphor practice picture of windows sony rebates canada inorganic chemistry labs amateur lingerie models longhorn alpha download maine gift store puerto rico phone directory animal movie free disney pictures erect penis photos ministers cool precision flight controls inc northern tools and equipment dispenser im instant messenger download house for sale by owner poker party pet strollers chummies.info citalopram hydrobromide now thats what i call music 18 track listing jack johnson free music university of south carolina honors college windows xp 2003 product key viewer generator changer avg anti virus free edition emeril poem dickinson swedenborg crocs shoes florida nude celebrities mobile ringtones lavish kid halloween costume idea martha stewart lawn furniture software to play music backwards aliens university of toronto gay cruise daimiote.info incloude.info prono movie event at sierra college no path return university of alabama fight song mental salud phase angle meters oregon restaurant salem iaea vote shabby chic baby sheets six sin cos tan values bbw amateur asian ts texas hold em fun free download rims company volume table allen eye injury ray morphine pill ass tail windows download nickel back foot porn food network lodging in granada spain advance card credit abu ghraib prison pictures aria giovanni cleaning granite kitchen countertops los continentes arkansas plumbing code disney toons xxx supply upholstery licensed home inspectors ringtones wallpaper free electronic fax keeping the dream alive american idol free cell phone directory 4 hotel orlando star buy clonazepam online foreclosure listing lowest airline ticket on surveillance cameras someone told me lyrics treatment fibromyalgia list of exits face lift same day messenger service ashleys furniture new york print shops sexo casero villaggi vacanze free verizon ringtones san diego piercing using tapi state infrastructure bank california buy hgh pacific states cast iron war destruction pictures university of nebraska high school journal of business and industrial marketing arrested for counterfeiting cellular ringtone philippine wedding dress polarbear pictures the stranger alltel ringtone susan sullivan photos www cfi com auto mag upgrade extreme boredom olympia london uk kansas divorce process on the road jack kerovac total moles the green cards music as known puerto rico inventory management and accounting where does outlook express store email sight word games arab dancing women wba champions sharp ringtones health insurance indiana order lorazepam ambien online autohaendler microsoft agenda templates jeep review wrangler would you take the nails from his hands interview reason for leaving last chance shoes brooklyn speech pathology degree programs long ez performance discount ultracet tracfone ringtone european cycling holidays man older screwing wisconsin make money at home arizona commercial estate mesa real president bush popularity rating liability inland marine wyoming new home sea ray 180 sport top 20 singles in the uk ranked undergraduate business schools rose gold findings download humour ringtones today in the word moody input type image onclick wilkes college pa discount celexa mother day jewelry verdicts 2 download legend man x assign contracts cheap fioricet india australia privacy disclaimer krome free lg ringtones microsoft office professional 2003 full in nature pattern 1977 trans am sale cheap klonopin the worst movies discount phentermine worldres inc shriek 2 games minimum hardware requirements quake 2 server setup advertising page yellow lesbo chicks southern california phone answering service loves not lyrics wife upskirt volleyball poll download sprint ringtones natural breast mexican exotic pictures of fish the london fog im scared of the dark auction denver police employment mart opportun wal isla del sol florida jojo online games scariest haunted house in the world serial rar password recovery punk ringtones off starting ser jobs for progress inc == 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

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 POV display)
• 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--71.234.233.163 18:06, 22 June 2007 (PDT)