Stepper Motor Controller

Parts

Part Total Qty. Description Substitutions R1, R2 ,R3, R4 4 1K 1/4W Resistor D1, D2, D3, D4 4 1N4002 Silicon Diode Q1, Q2, Q3, Q4 4 TIP31 NPN Transistor (See Notes) TIP41, 2N3055 U1 1 4070 CMOS XOR Integrated Circuit U2 1 4027 CMOS Flip-Flop S1 1 SPDT Switch MISC 1 Case, Board, Wire, Stepper Motor You should be able to substitute any standard (2N3055, etc.) power transistor for Q1-Q4. Every time the STEP line is pulsed, the motor moves one step. S1 changes the motors direction.