Stepper motor is an actuator that converts electrical pulses into angular displacement. Generally, the motor is continuously rotated, and the rotation of the stepper motor is carried out step by step. Each input pulse electrical signal, the stepper motor rotates at an Angle. By changing the pulse frequency and number, you can achieve speed regulation and control the angular displacement of rotation, with high positioning accuracy, the minimum step Angle up to 0.75°, rotation, stop, reverse response sensitive and reliable. It has been widely used in open loop numerical control system.

Classification of stepper motor:
    1. Permanent magnet stepper motor: permanent magnet is generally two-phase, torque and volume is small, stepping Angle is generally 7.5 degrees or 15 degrees.
    2. Reactive stepper motor: reactive stepper motor is generally three-phase, can achieve large torque output, stepping Angle is generally 1.5 degrees, but the noise and vibration are very large.
    3. Hybrid stepper motor: hybrid stepper motor refers to a mixture of permanent magnet and reactive advantages. It is divided into two phases and five phases. The two-phase step Angle is generally divided into 1.8 degrees and the five-phase step Angle is generally 0.72 degrees. This kind of stepper motor is the most widely used.