Let's Make Robots!

A guide to H-bridge design and motor interfacing?

I'm going to need a pair of H-bridges for The Heavy soon.

Each needs to control a 180Watt motor at 12v, but (ideally) be able to run 24v to the same motors at a later point in development. So looking at 15Amps per controller. 20 for safety?

I want to run them with PWM, and be able to change direction quickly, as well as lock the motor and set it to freewheel.