A motor power controller can be constructed from 4 discrete power MOSFETs that are joined connected as shown in the diagram below:
The 4 power MOSFETs constitute a bridge. The control input switches on the transistors in pairs. Either Q1 or Q4 are on or Q2 and Q3 are on.This switches the current through the motor in just one direction or the other, functioning as a reversing switch.
