Stepper motor and its drive circuit schematic

Stepper motor is one of the most commonly used control components in industrial control and instrumentation. It has the characteristics that the input pulse is proportional to the motor shaft. It is widely used in intelligent robots, floppy disk drives and data machine tools. Microcomputer control stepper motor is most suitable. The system is designed to use 20BY-0 type stepping motor, which is practical +5V DC power supply, the step angle is 18 degrees, and the motor coil is composed of four phases. As shown in the figure below, four phases A, B, C, and D. The drive circuit is controlled by a pulse signal, so adjusting the frequency of the pulse signal can change the speed of the stepper motor. On the way, BA, BB, BC, BD are the pulse signal input jacks, and the drive outputs A, B, C, and D are connected to the stepping motor.