I had immediately into my document. I do not know where it came from, but it seems that I photocopy a few years.
I think it should be very helpful, so I decided it here. The circuit is very simple and inexpensive. It is a good thing, since most lines step motor controllers are very expensive. The circuit is made of standard components and can easily be adjusted by a computer. If you cheap surplus transistors and stepper motor, the price of the circuit can be less than $ 15.
This stepper controller circuit shown here can used to control the unipolar stepper motor,which has 4 coils . The stepper controller circuit can drive for a motor current of up to about 500 mAmp/Winding by suitable heat sinks for the SL-100.
In higher currents power transistors seem 2N3055 can be used as darlington pair along with SL-100. All diodes are used to protect back current the transistor from transients.
*** Remark ***
- You may be able to substitute any standard (2N3055) power transistor for Q1-Q4 or
get IC type UL to modify for transistor.
- Every time in move the motor put signal the STEP line is pulsed, the motor moves one step.
- Switch S1 for changes the motors direction
Low Cost Stepper Motor Circuit with IC 4027
