My idea was to build a solid state winch controller for my ATV. I was looking to replace the high powered relay with mosfets. The idea was to build a h-bridge and connect it to the winch.
Now I ended up destroying my board and mosfets because of a mistake in building my circuit. I ended up cross wiring the low sides of the h-bridge which created a dead short when I activated the circuit.
Unfortunately that's as far as I got. I have no extra parts to build the circuit a second time.
That being said, there were a few issues I had to overcome that I will try to describe
- From the start I had an issue with using the MOSFETs for an h-bridge as they all were n-channels. To overcome this, I use an h-bridge driver ( ir2109 ). These h-bridge drivers allowed me to use a single power source to drive the mosfet as well as trigger the gates.
- The next issue was the 600 V CoolMOS™ C7 Gold superjunction MOSFETs are surface mount. For some reason I didnt realize it until I got some. I ended up soldering leads to them but that would only work for a quick prototype.
- next issue is where these mosfets were surface mounts, I had no way to hook up heat sinks. Major issue because winches can use upwards of 200A.
- 200A, this is the next thing to overcome. these mosfets were rated around 75A. it really isn't big enough. But for testing I was using a small winch and no load on the cable. To make this work under load I would have to place 2 -4 of the mosfets in parallel for each of the four sides.
I was really hoping this would of worked, but the issues proved that it probably wouldn't be feasible. To be able to control a standard 3000 lb winch, you would need around 16 mosfets, 4 in parallel in each of the sides. Then the heat created would need heat sinks, which would make the finished packaged as big or bigger then the existing relays..