[CamLight]

Originally Posted by jyanof

Yah, the fan/heatsink seems to work well. I had thought about using heat pipes for an IGBT based power section. But, this is a whole other discussion

As for mosfet heat generation, it depends (mathematically at least) which term - resistive or switching - dominates the heat generation. The formula for switching losses is linear with respect to current, whereas the resistive losses are proportional to current squared as you mentioned. In our case, with the 20 ohm gate resistors in the controller and the really low Rds_on characteristic of the mosfet, the switching term greatly dominates the heat generation of the mosfet. Thus, the heat generation appears to be roughly linear with current (as calculated).

Good points, I agree.