The H-Bridge is a circuit which can drive a motor in forward and reverse. It can be a very simple circuit that requires only a handful of components to build. This Instructable demonstrates how to breadboard a basic H-Bridge. Upon completion you should be familiar with the basic operation of an H-Bridge and be ready to move on to more complicated versions that can support larger, more powerful motors.
Step 1: Gathering the Parts
Only a handful of parts are needed.
1) A bread board
2) A small DC motor capable of operating at ~7 volts
3) A 9-volt battery and battery snap
4) Four small signal NPN transistors. We're using the 2N2222A here. 2N3904 is another common part number and thousands of others will do.
5) Four 22k ohm resitors
6) Two push button switches
7) Jumpers or spare wire to hook everything up