Learjet
Enlightened
**** 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?
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?