Help with an H-Bridge

Thread Starter


Joined Jun 26, 2011
Hi, so me and two of my friends decided, that we should build a electric racer.

we decided we should use two 500W DC motors, and i, being the circuit guy, started looking into, well the circuits. However, i have never done anything with motors, but i do know, that what ill need is an H-Bridge.

The specs of the motor:

  • 36V
  • 500W
  • 17,5A

I though of making an H-Bridge, consisting of 2 P-channel, and 2 N-channel, but then thought, that that would be a hell of a lot of power to run over two mosfets.

other than that, i dont really know how to choose a mosfet. How much should the rated amps be above what i need? Could i run several mosfets paralell to split the load out and reduce RdsON, or should i go with power BJT?

The H-Bridge would be controlled by an arduino, the output of the pins on that would be 5v 40 mA (though i wouldn't run the pins at more than 30 mA to be safe)

so yeah, thanks a lot for taking a look :)