Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Heres a much larger diagram (based on the one above) of circuit that can control the speed and direction of rotation of 4 DC motors.
I designed and built this circuit a couple years ago to control motors via the parallel port of my computer, if you dont need computer control simply leave out the DB25 connector and use pushbutton switches or what have you.