Unipolar Stepper Motor Controller

Below are some images of a stepper motor controller I made for testing stepper motors. The body is a plastic inclosure I bought from a local electronics surplus store for a few bucks. The transistors are power darlingtons. Type TIP142, but this exact transistor is by no means essential in this project. I used them with the knowledge I would be working with some motors with high current loads. The motor this controller was intended, for the most part, had one ohm coils at a nominal 12 volts. Average of 4.5 amps, with no load, and at a moderate speed range. Lots of torque in that motor! I have made a zip file of the schematic and a pc board layout suitable for creating printed circuit boards. Both require down loading a share ware copy of the programs to view and print out copies. The links to these two fine programs are given below.