badboy heatsinking

[dangee]

i am modifing a brinkmann nexstar 2c to receive waynes badboy 400 full sandwich. how much heatsinking will this need, as currently there is no way to use the aluminum barrel as on the minimags. there will be plenty of room in the head for some kind of heatsink. i plan on using thermal paste (not epoxy) to help transfer the heat to the heatsink. can i just fabricate some kind of a aluminum slug and attach it to the area around the emitter? i think it will have to be on the thin side as to allow the optics to fit close to the luxeon

 

[Doug S]

I am working on a long-winded post on thermal design in general that I hope to post soon. Perhaps you will find it of some value.

 

[MicroE]

Dangee---The 1 Watt LS on 400 mA doesn't require much heatsinking. There should be a reasonable thermal path from the LED to the housing, but the standard top board of the sandwich is sufficient for this purpose. Just make sure that the top board is in mechanical contact with the light's housing.

Heat moves by conduction, convection and radiation.

If there is no mechanical path (conduction) for the heat to get to the housing then the temp will rise inside. Eventually the heat will begin to transfer to the case through convection. This is less efficient. If you must use convection then use as much metal as possible in contact with the LED slug and cross your fingers. Is there enough room for a muffin fan?

If you mount a 5W LS on the BB you will want to improve the thermal path somewhat. I used 0.2" (5mm) thick machined aluminum to transfer the heat from a 5W to the case of an E1e or a Legend 2AA. They work fine, but the case temperature is 100 F (38C) after 15 minutes.

As Wayne warned me, it is a good hand warmer in the winter!---Marc

 

[Doug S]

Originally posted by MicroE:
Dangee---The 1 Watt LS on 400 mA doesn't require much heatsinking. There should be a reasonable thermal path from the LED to the housing, but the standard top board of the sandwich is sufficient for this purpose. Just make sure that the top board is in mechanical contact with the light's housing.

If you mount a 5W LS on the BB you will want to improve the thermal path somewhat. I used 0.2" (5mm) thick machined aluminum to transfer the heat from a 5W to the case of an E1e or a Legend 2AA. They work fine, but the case temperature is 100 F (38C) after 15 minutes.

As Wayne warned me, it is a good hand warmer in the winter!---Marc

<font size="2" face="Verdana, Arial">I know that Marc isn't actually saying this but some might interpret his last statement to imply that the case temperature is related to the quality of the thermal path from the LED to the case. It is not.

 

[MicroE]

Doug S.---My bad grammar strikes again!

How about this: "Boy does that little E1e get hot!"---Marc