On Sat, May 20, 2006 at 01:09:18AM -0700, William Chops Westfield wrote:
> 
> On May 20, 2006, at 12:07 AM, Jason wrote:
> 
> > I'm looking for a high power LED like a Luxeon III that has red green  
> > and blue dies in a single emitter unit.  Does anyone know where I can  
> > get something like this?
> 
> eBay has become a direct retail outlet for a bunch of chinese LED
> manufacturers:
> 
> http://cgi.ebay.com/1P-Prolight-3W-High-Power-RGB-LED-Full-Color-PG1L 
> -3LFS_W0QQitemZ7621013046QQcategoryZ66952QQrdZ1QQcmdZViewItem
> 
> IIRC, this vendor has a reasonably good reputation...

On that note... Be carefull. I've bought about 3000 LEDs of various
types from cwithk on ebay. Of those many have the polatity markings on
the epoxy case, the flat side, different than the longer lead marking.
In a batch of 1700 flashing RED leds I once ordered and installed by
hand about %1 had this defect. Didn't cause me any problems, but
automated equipment might be a different story.

Another batch of 100 high intensity blue LEDs worked fine to produce
light. But the reverse current leakage was completely unacceptable for
use in an LED matrix. Around %5 of the LEDs would light up fine, but
they just were not acting as diodes, as much current would flow in the
reverse direction, without producing any light. They also seemed to fail
progressively over the course of a few days of testing. This was at
proper votlage levels with a current limiting power supply and before I
had even hooked up any other circuitry, just the power supply connected
via clips.

Of course, in both cases, the LEDs were at a very reasonable price. :)
For the flashing LEDs they were simply the only place I could find LEDs
that I could afford. cwithk was a tenth of any other price I could find.
I will be buying more in the future from them all the same.

-- 
pete@petertodd.ca http://www.petertodd.ca
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