I am no longer maintaining the electronics sections of this site. For an explanation, see the electronics contact page.

Stepper Motor Controller


I found this circuit in my files. I don't know where it came from, but it looks like I photocopied it from somewhere years ago. I have been told that it came from "The Robot Builder's Bonanza", by Gordan McComb. Anyway, I thought that it should be fairly useful, so I decided to post it here. The circuit is very simple and inexpensive. This is good thing because most commercial stepper motor controller ICs are quite expensive. This circuit is built from standard components and can easily be adapted to be controlled by a computer. If you use cheap surplus transistors and stepper motor, the price of the circuit can be kept to under $10.

Schematic


This is the schematic of the Stepper Motor Controller

Parts
Part
Total Qty.
Description
Substitutions
R1, R2 ,R3, R441K 1/4W Resistor
D1, D2, D3, D441N4002 Silicon Diode
Q1, Q2, Q3, Q44TIP31 NPN Transistor (See Notes)TIP41, 2N3055
U114070 CMOS XOR Integrated Circuit
U214027 CMOS Flip-Flop
S11SPDT Switch
MISC1Case, Board, Wire, Stepper Motor

Notes

1. You should be able to substitute any standard (2N3055, etc.) power transistor for Q1-Q4.

2. Every time the STEP line is pulsed, the motor moves one step.

3. S1 changes the motors direction.

Back to Circuits Page | Mail Me | Search