OT: white LEDs

Randy Dawson rdawson16 at hotmail.com
Mon Feb 22 21:20:31 CST 2010

I think Luxeon still has the high mark in the industrial high power LED market.  When these first came out, 6 years ago they were truly amazing, 1 amp LEDs!  Integral thermal pad on the back for heatsinking.  In the dark, you could hold a 35mm slide in front of one, 6" away and get a sharp bright image in the wall, as its almost a point source.

If you look at one in the microscope, it looks like an LED with some sort of phosphor painted over the semiconductor.  Is that how these things work, its really a high efficency IR LED, with a phosphor doubler to bring the wavelength into visible?  Just speculating...

I was using them in a ring light for a downhole well camera.  Not that expensive, about $6 each.


> Date: Mon, 22 Feb 2010 20:49:47 -0500
> From: curt at atarimuseum.com
> To: 
> Subject: Re: OT: white LEDs
> That is true, they last longer and would save a heck of a lot of 
> maintenance... I always thought like 10-15 years ago "when will they 
> make traffic lights and street lights smart enough that when they fail, 
> a signal is sent so that someone will come and fix them..."   Today its 
> usually when a traffic signal breaks and someone calls on their cell to 
> 9-1-1 that there is a potential safety hazard, I would assume the 
> electric co. drives around making inspections looking for dead street 
> lights.    I would think that with their new low power lights there 
> would then come the eventual Wifi status transmitter that would send out 
> a functional status of a light, traffic signal, etc that could all come 
> into a center monitoring station and know when something fails.
> I was incorrect on the LED's as you pointed out, the more industrial 
> type LED's are far more expensive.
> Curt
> Alexander Schreiber wrote:
> > On Mon, Feb 22, 2010 at 05:56:43PM -0500, Curt @ Atari Museum wrote:
> >   
> >> Nice!!!       Definitely should see those nationwide, its ashame they  
> >> cost so much which I mean - they are LED's, they are a couple of cents  
> >> each, its this all profit gouging on Green Products???
> >>     
> >
> > A couple of cents? Yeah, for the small low power (<< 1 W) ones you use
> > for indicators in electronics or christmas tree lights. The high power
> > stuff is still rather pricey. While I've no doubt that the manufacturers
> > are milking every cent of profit they can, those _aren't_ that cheap or
> > easy to produce, otherwise every semiconductor fablet in china would
> > make them by the barrel.
> >
> > Also, make no mistake, the "green" aspect takes a second (or third) seat
> > to more important aspects when deploying LED for things like traffic
> > signs and such. Especially for traffic sings, while the LED versions
> > most likely are significantly more expensive than incandescents, they
> > are big money savers in maintenance (getting someone up with a ladder to
> > change bulbs every once in a while ain't that cheap, especially in
> > places like Switzerland where there _is_ no dirt cheap labor) and
> > operating costs (power bills). The reduced power consumption of course
> > lends itself to being toutet as "greener" ;-)
> >
> > Regards,
> >        Alex.
> >   
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