Heatsinks?

[obscurity]

Does anybody have any recommendations on heatsinks for the LMD chips? I have some small 5watt (I think) heatsinks on there now but once I have them under load I'm sure they will prove too small. What is everyone else running?

Thanks,
John

[lucas]

You will need massive heatsinks if you're running them close to the 3A without active cooling.

I also use small ones with 2 80mm fans blowing right down on 4 picsteps, works fine and fans are cheaper.

[vladdy]

I used some salvage heatsink material on the ver2 picsteps I built some time ago, they were slightly longer than the width of the LMD rear portion of the board, and about 1 1/2" square in profile, only four [or maybe 5] fins in total. Idea was to mount vertical with heatsink up, and basically touching each other, with a angled mount so that it formed a closed channel. One fan at each end should be enough 'forced' air flow to keep things cool..
They bench tested ok [quite some time back] without air flow, but haven't been mounted or 'worked' as yet..

enjoy..

[PsyKotyk]

I found a pretty good source of heat sinks from old computer power supplies. There are usually a couple per PSU, and are fairly large (not particularly thick mind you).

Almost certainly need a fan blowing at or mounted on the heatsink.