Best Heat sink?

[da.wells]

I recently bought some mc-e and some 42mm aluminum reflectors with the copper heat-sink from DX, i have enclosed it in an aluminum housing, i am running it at 700ma and it is still getting pretty warm, is that expected or should i ad some extra heatsink to it. what would you use?

 

[Steve-at-Springboard]

Depends on how warm. Too hot to touch? Uncomfortable? Toasty? Smells like smoke? Find some way to give us a number. Oral thermometer, doctor's office, ??? Some of the race car guys have infra-red digital thermometers, Harbor Freight sells a cheap one, maybe you can try theirs.

Anyhow, our lights have to get a little warm to get rid of the heat, through convection, conduction and radiation. The equations for all three types of heat transfer include a term for the difference in temperature between the object trying to get rid of the heat and what is receiving the heat (air, your hand, etc.). If there was no difference in temperature, the flashlight could not get rid of the heat it is generating and would get hotter, until there WAS a difference in temperature or....the light stops working.

Even though LEDs are more efficient than incandescent bulbs, the high-brightness (HB) LEDs we like still convert 85-90% of the electrical power they consume into heat. That heat has to go somewhere.

 

[Jayls5]

Depends on how warm. Too hot to touch? Uncomfortable? Toasty? Smells like smoke? Find some way to give us a number. Oral thermometer, doctor's office, ??? Some of the race car guys have infra-red digital thermometers, Harbor Freight sells a cheap one, maybe you can try theirs.

Anyhow, our lights have to get a little warm to get rid of the heat, through convection, conduction and radiation. The equations for all three types of heat transfer include a term for the difference in temperature between the object trying to get rid of the heat and what is receiving the heat (air, your hand, etc.). If there was no difference in temperature, the flashlight could not get rid of the heat it is generating and would get hotter, until there WAS a difference in temperature or....the light stops working.

Even though LEDs are more efficient than incandescent bulbs, the high-brightness (HB) LEDs we like still convert 85-90% of the electrical power they consume into heat. That heat has to go somewhere.

You can get a multimeter at walmart that has a thermocouple thermometer... measures within like 1-2 degrees up to around 700 F. It's around $20-25 in the automotive section.

 

[da.wells]

i will check it with a thermometer. but i do know that after 30 or so minutes it is unconfortably hot.