Help finding what kind of LED this is...

Thread Starter

Lectraplayer

Joined Jan 2, 2015
123
I'm about to rebuild a Staley LED spotlight, and while I have found out it's a Cree LED, the only thing I know about it is billed as a 5 watt emitter. The orlgial circuitry is eating NiMH batteries, so I'll pull all that out and build a current source driver to push the emitter from a lithium ion battery at anywhere from 10mA to 1 amp when on, and I may also implement a (barely on) "finder" mode when off. Where do I find specs on these things? I have dealt with 5mm indicators, but that's about it.
 

Thread Starter

Lectraplayer

Joined Jan 2, 2015
123
Looking... Looking... Nothing I see yet looks like a 5 watt component LED. I would think it would be here.

I guess I'll have to guess...
 

Thread Starter

Lectraplayer

Joined Jan 2, 2015
123
I'm starting to think it's an XP-G. The XP-E looks like a 3.5 watt. I wonder if they overdrive it. I know it has a big heatsink on it, and if you turn the brightness above the midpoint, the lamp gets warm without getting much brighter. Could this be a sign of overdriving?

Anyway, I think I have something to check against now... ;)
 

Thread Starter

Lectraplayer

Joined Jan 2, 2015
123
I got some values to play with for now. I had it at 6mA @ 2.4 volts on the LED, 500mA @ 3.2 volts (which appears to be the sweet spot for now) and 900mA @ 3.6 volts, all resistor ballasted. I'm still interested in pushing 1.5 amps to determine the thermal capabilities of this arrangement. I have it at 900mA at the moment.

My next quest will be the "finder" mode previously mentioned. I put a 1K-ohm resistor on it (on USB supply) and it's still much too bright. I bet a 10K-ohm will have me in the upper 1.x volts at a couple hundred microamps. Since I want it "barely on" as in "I can barely see it in a dark room" this may still be too bright, but I will try it next. Anybody have a better idea what value to try?
 

Thread Starter

Lectraplayer

Joined Jan 2, 2015
123
It lasted a couple hours like this, but I think it now burned out at 5.5 watts. It uses a "bowtie" style "star. I've tried to post a picture of the mounted LED with a 5 watt resistor placed for reference, though I don't know it posted. I have a couple 1 watt LEDs which are half the physical size of this LED which I could continue to work with, but the stars won't mount properly. Has anybody ever taken an LED off its star, and put it on another star for one reason or another?
 
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