I was bored and kinda mad that I couldnt get my microcontroller working, so to relieve the pressure, I built a Dual H-bridge motor driver. The motors are powered by a AA battery pack, and the control signal can be powered by a 9 volt. It works good and has the following parts:
8 NPN PN2222A Transistors
4 PNP PN2907A Transistors
4 1/4 100 Ohm resistors
4 1/4 1k Ohm resistors
A H-Bridge is a special circuit that you can use with analog, digital, or even microcontroller systems. It can drive a motor backwards or forwards, and you could even vary the speed with a few more components.
1359: Side view of transistors and motors.
1360: Birds eye view of circuit at an angle;
1361: the whole thing. The 4 red wires at the lower end of the board are the signal inputs. the red wire at top is the 3v 2.5 amp input. The 9 volt would connect to one of the 4 signal input wires, or the 9 volt would control a circuit that would control the H-Bridge. you could use this for a walker robot, where you would need legs that go back and forth.
EDIT: 1359 somehow got mixed up with a picture of my dog, reggie