CMG ultra -G

[RussH]

Does anyone know what chip is used for this flashlight? I've experimented with various kinds of batteries in mine, including a SAFT AA lithium 3.6v. I'd like to make sure that the 3.7v (measured open circuit) from this battery wouldn't damage the chip. Not that I would likely use a $6 battery in this light when an 84 cent 1800ma NiCad works so well (about 12hrs full brightness, as near as I can tell).

 

[B@rt]

Nukiez did some exploring /ubbthreads/images/graemlins/icon15.gif /ubbthreads/images/graemlins/tongue.gif and found it to be a Zetex circuit. /ubbthreads/images/graemlins/wink.gif

Check out this thread for info and pics:
Guess where this come from... /ubbthreads/images/graemlins/thumbsup.gif

Oh, I almost forgot... /ubbthreads/images/graemlins/ohgeez.gif

 

[RussH]

Thanks for the reference - my search either didn't turn that up or I bypassed it for some reason. I think I searched for CMG Ultra-G since that's what I have.
I noted that nukiez was a little surprised at the 66ma. driving the LED. I'm not, I've driven them up to about 100ma, sometimes more. Somewhere around 100ma, you can get thermal runaway which will kill one in a few seconds. But a small resistor or low voltage (like the 3.4) can prevent the thermal runaway up to a point.
I suspect 60ma. might shorten the life, but I've had some LED's (various colors) in mini mags for years drawing over 60ma (no resistor) with no problems. I've had a white LED in one for 2 years (100hrs use?) running on 2 lithium 1.6v batteries (about 3.3v open circuit). Hey, any thing over 20,000 hr. life will do in a flashlight where bulbs used to last 5, maybe 10 hrs. RussH