Say I bought you a RC car as a gift, that works on 24v battery. You decided that RC car are boring and want to control it with raspberry pi 2. There are two motors on the car.

You bought a voltage regulator, you reduced 24v to 5v and were able to get the signal in the Pi. But the car works on a 24v so all the commands you send to the motor should be 24v, how to increase the voltage back for the motors to run? The wires are on an extension board like this. If you could show me a diagram on how to connect it, it would be great. All DC current.