Stepping motor is also called pulse motor, based on the most basic electromagnet principle, it is a kind of electromagnet that can rotate freely, and its operating principle is to generate electromagnetic torque by the change of air gap permeability. Its original model originated between 1830 and 1860. Around 1870, attempts were made for the purpose of control and applied to the electrode conveying mechanism of the hydrogen arc lamp. This is considered the original stepper motor. In the early twentieth century, stepping motors were widely used in automatic telephone exchanges. As Western capitalist powers competed for colonies, stepper motors were widely used in independent systems such as ships and airplanes that lack AC power. The invention of the transistor in the late 1950s was gradually applied to stepper motors, making digital control easier. After the 1980s, as cheap microcomputers appeared in a multi-functional posture, the control methods of stepping motors became more flexible and diverse.