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.
ConclusionI 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..
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