Stepper Motor Controller using IC 4027

The stepper controller circuit is very interesting, since most lines the 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 motors, the price of the circuit can be less than $ 15.

Stepper Motor Controller Circuit using IC 4027

This stepper controller circuit shown here can used to control the unipolar stepper motor, the which has four 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 seem 2N3055 power transistors can be used as darlington pair along with the SL-100. All diodes are used to protect the transistor from back current transients.

List Componet

R1, R2 ,R3, R4: 1K 1/4W Resistor
D1, D2, D3, D4: 1N4002 Silicon Diode
Q1, Q2, Q3, Q4: TIP31 NPN Transistor (See Notes) TIP41, 2N3055
U1 : 4070 CMOS XOR
U2 : 4027 CMOS JK Flip-Flop
S1 : SPDT Switch

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.

4027 CMOS JK Flip-Flop IC  Pinout

4070 CMOS XOR IC Pinout