Re: LED's

[c a l i b a n <caliban@sharon.net>]

	interesting.  also, a plus for led's is that they 
	light up much closer to totally instantly than regular
	incandescent.  this is a ctually a major reason that
	they are becoming standard.  also their low voltage
	usage has made them popular in warning signs, often
	able to be solar powered and totally off that pesky
	grid.  traffic signal red lights in many cities have
	been switched over - and they have this weird effect
	of "flashing" on, which is probably a good safety 
	feature.  i dunno if it is intentional or not.

On Fri, 6 Nov 1998, Wallace White wrote:

:|The reason that LED's effective efficiency is so much greater than
:|incandescents for tail lights and such is that they emit nearly
:|monochromatic light. So if you want a red tail light, you just use a red
:|LED, instead of an incandescent light bulb and a red filter that throws
:|away most of the light. For the same reason, it's unlikely that we'll
:|see LED back-up lights, besides the fact that white LED's are rare and
:|expensive right now; LED's are more efficient (visible light per input
:|energy) than incandescents only at pretty low power. LED headlights
:|would be nowhere close to HID lighting, nor conventional halogen lights,
:|if I remember the numbers correctly.
:|
:|Regarding the ice issue (which I never would've thought of here in
:|CA--good point), maybe you could build a tail light cluster that has
:|some IR LED's thrown in to the array, just to use as heat lamps, and
:|have your tail light lens be IR blocking. That way you'd be putting heat
:|on the lens, which might even do a better (more efficient) job of
:|melting ice than having an incandescent bulb that has to heat everything
:|up to heat the lens.
:|
:|But maybe not!
:|
:|- Wallace
:|  '87 5kcstq 150k, LED advocate
:|
:|Bob Davis wrote:
:|> 
:|> LED's are cool - they require a lot less power to generate light, and they
:|> practically never burn out.
:|> 
:|> One thing to note though - for those of us in living in colder climates.
:|> They have such a high light/power ratio because they don't waste energy on
:|> heat.  They are very cool.
:|> 
:|> If you think you have troubles keeping your current incandescent lights
:|> clear of ice and snow, you'll hate LED's.
:|> 
:|> Bob Davis
:|> bob@segNET.COM
:|> 
:|> http://www.segNET.COM
:|
:|--
:|
:| Wallace White                             wallace@remdesign.com
:| REM Design                                     tel 415.621.3922
:| 290 Division St., Suite 401                    fax 415.621.4024
:| San Francisco, CA  94103                      www.remdesign.com
:|


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