|
If you have built a PWM controller before this is basically the same. The only difference is instead of using a single or a pair of mosfets you are wiring a lot of them in parallel. There are some good 35 amp mosfets out so with those wiring up 20 of them would make it able to handle pretty much anything the batteries can do without the batteries sustaining damage. I would say group the mosfets into 3 or 4 and wire each group with 8ga wire on the load carrying parts. Then keeping the wires short and neat put them all together and attach to the normal heavy current wire with a large solid copper screw clamp. The mosfets will need heat sinks to keep cool but it should be easy to find an old car stereo amp and use for the housing.
If you don't plan on using a transmission for reverse you could wire in maybe 10 extra mosfets for reverse, Just limit them to 25% duty cycle or something and they will probably be fine for the limited use they will see.
There is nothing really magic in a controller it just takes a bit of care making sure the mosfets and power wires can handle the current loads of the motor. Other than that it is the same as any small remote control car speed controller. With some of the components out now though it should be an easy thing to build really.
|