7x XM-L T6 Flashlight!

[Benm]

How much current do you plan to run this thing at in the end?

Not to be pessimistic, but running it at 50 watts or more will always be problematic since it will get very hot, even if the thermal resistance between driver, leds and housing is perfect - it's just not big enough.

I've seen similar sized led lights that are rated well over 50 watts in total, but those are all dive lights, and can only be operated (for more then a minute or so) when underwater - that immediately solves the cooling problem.

 

[AutoItKing]

How much current do you plan to run this thing at in the end?

Not to be pessimistic, but running it at 50 watts or more will always be problematic since it will get very hot, even if the thermal resistance between driver, leds and housing is perfect - it's just not big enough.

I've seen similar sized led lights that are rated well over 50 watts in total, but those are all dive lights, and can only be operated (for more then a minute or so) when underwater - that immediately solves the cooling problem.

Full power, 3A at 23V. Screw cooling, I don't give a care. :wave:

 

[Benm]

Hehe... so you are that guy holding the flashlight with oven mits?

Seriously, if you dissipate 70 watts in that enclosure it will be to hot to hold onto within the minute, and probably suitable as a grill within 3, if the components and batteries survive that much heat - i suspect something will unsolder itself before that point though

 

[AutoItKing]

Hehe... so you are that guy holding the flashlight with oven mits?

Seriously, if you dissipate 70 watts in that enclosure it will be to hot to hold onto within the minute, and probably suitable as a grill within 3, if the components and batteries survive that much heat - i suspect something will unsolder itself before that point though

Yeah, that's me!
It doesn't get too hot, I've ran it off my powersupply at full power for a good two minutes. It was hot, sure, but not unbearably so.

 

[Benm]

It must have more thermal capacity then i imagined then. But still, considering the size and shape of the host, this will not able to dissipate 70 watts continously without getting to hot to burn your hands on. Perhaps it will be okay for practical use for a few minutes after all.

Still, i consider any flashlight or laser ill designed if heatsinking is not adequate to sustain continous operation. If you want to use it as a practical real world flashlight, there will be a moment you want to use it all the way from full batteries to complete discharge without burning somehting out or blistering your hands while holding it.

At these power levels the only way to do so is to use active cooling, or use a host the size of a baseball bat with fins throuhout its length.

 

[AutoItKing]

Dude, I know this!

I'll probably include a low power mode (around 20W) to save the batteries. The full 70W mode will only be for when I need a lot of light.