"Cyclops" 1 watt LED & questions

**** Smith Electronics have these "Cyclops" 1 watt power LEDs. I assume they are some kind of Luxeon clone? Anyway I bought a 1 watt white LED to play with and perhaps install it into a 3D torch of some kind.

The LED comes with no heatsink. How hard can I drive it without a heatsink before it goes into thermal runaway? What does thermal runaway look like on the amp meter? With inadequite heatsink does the current continue to climb until it overheats?

I don't have a constant current source so plan on driving it on 3 cells and a resistor. Some preliminary experiments show these results.

2 AA nimh cells direct drive = 6.7ma.
3 AA nimh cells & 15 ohm resistor = 54ma.
3 AA nimh cells & 10 ohm resistor = 70ma.
3 AA nimh cells & 8.2 ohm resistor = 79ma.
3 AA nimh cells & 6.8 ohm resistor = 87ma.
3 AA nimh cells & 4.7 ohm resistor = 100+ma.

All readings except the last one tended to stabilise. Wasn't sure if 100ma without heatsink is safe or not so didn't leave it connected for long.

Where do I connect a heatsink to this thing? Solder something to the slug at the back?

sure looks like a clone, how much were they selling it for?. Did they have other types available?

They were $9.98. Other colours available. http://dseau.resultspage.com/search...7f00bb01d22740c0a87f9c06f1&site=&w=1+watt+led

Mmm, I don't see how I can use the slug at the back as a heatsink since they say in the destructions not to connect either the anode or cathode to it. I wonder if connecting the +/- legs to metal would be enough.

Thanks for the link Learlet,
not too sure how you can heatsink, I'm quite an amateur at soldering and modding.

Been playing around some more. I made a bulb replacement out of this emitter thingo. Found an old bulb, broke the glass, dug out the potting, soldered in some resistors into the case with a bit of heatshrink around them, soldered the emitter on top and bingo, a 3.6V bulb replacement!

Bought a cheap 3D aluminium Chinese mag clone the other day to fool around with so I tried the new LED bulb in it and it works great! Running now at around 100ma, seems stable. Must be the extra metal on the legs?

Beam is focusable and makes a nice spot when focused. Not quite as bright as an incan bulb, probably cos it's under driven but it sure draws a lot less current. Should increase runtime by about 7X.

Ah well I'm having fun!