Quote:
Originally Posted by Renny_D
On the heat spreader I assume thicker is better but has any body done a fined one? I thought of just getting a block and a carbide bit for my table saw and doing some machining of fins for better cooling?
PS would love to see more videos and pics of completed units and completed units in cars.
|
Regarding the heat spreader, it's purpose is to move heat to the heat exchanger (whatever you happen to choose as your heat exchanger - i have a finned heatsink under the baseplate) and keep a more uniform temperature across all the mosfets and diodes (particularly the diodes).
If it's too thick and increases the distance between the mosfets and heat exchanger, you'll lose thermal efficiency and the controller will run hotter. Too thin and you'll increase the likelihood of different component temperatures.
Regarding the base plate, a thinner material may help if you have a heat sink attached to the bottom. You want to get the components as close to the heat exchanger as possible. In fact, removing the base plate and having the heat spreader bolt right to the heatsink would be best, though I think the actual difference may be insignificant, like a couple degrees.
If you don't have a heatsink/coldplate/heatpump or something, you better be taking short trips at low amperage and/or low voltage. A large baseplate may have enough thermal mass to 'soak up' the heat after a short drive, but without a real heat exchanger that heat will stay there for a while.
Here's a picture of the Curtis I had before - the Cougar is now in its place. You can barely make out the heatkink fins underneath - there's also 3 muffin fans moving some air through the heatsink fins.
