Difference between revisions of "POV display"

From OpenCircuits
Jump to navigation Jump to search
m (Protected "POV display": spam magnet [edit=sysop:move=sysop] (expires 20:02, 24 October 2007 (UTC)))
Line 1: Line 1:
−
== POV display ==
+
I really find this site very interesting, and it gives people a pleasure time!
 +
I really appreciate the creators of this website!
  
−
A "persistence of vision display" (POV display) has only a single line of LEDs blinking on and off.
+
[http://mature-clips-free.hourdrozd.cn/ mature facial pics] |
−
The display mechanically sweeps it across a person's field of view,
+
[http://mature-lesbian-sex-video.hourdrozd.cn/ mature parental secret] |
−
giving the illusion of a 2D display.
+
[http://elder-erotica-hardcore-mature.thmanyellow.cn/ cure ejaculation enlargement isreviewinfo penis permanent pill premature] |
−
 
+
[http://free-mature-movie-post.thmanyellow.cn/ groupsmsncom mature site wife]
−
''(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 ==
 
== further reading ==

Revision as of 04:47, 25 October 2007

I really find this site very interesting, and it gives people a pleasure time! I really appreciate the creators of this website!

mature facial pics | mature parental secret | cure ejaculation enlargement isreviewinfo penis permanent pill premature | groupsmsncom mature site wife

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=10098"