步进电机是将电脉冲信号转变为角位移或线位移的开环控制元件。在非超载的情况下，电机的转速、停止的位置只取决于脉冲信号的频率和脉冲数，而不受负载变化的影响，即给电机加一个脉冲信号，电机则转过一个步距角。-Stepper motor is the electrical pulse signal into angular displacement or line open loop control elements of displacement.In the case of the overload, motor speed, stop position depends only on the pulse signal frequency and pulse number, and not affected by load change, which give the motor a pulse signal, a step　the Angle of motor is turning.