Brief introduction to stepper motor

As an executive component, the stepper motor is one of the key products of mechatronics and is widely applied to various automatic control systems. With the development of microelectronics and computer technologies, the quantity demanded of stepper motors is increasingly growing. It is applied to each domestic economic field.

The development of stepper motor

The last century has seen the emergence of the stepper motor that is a freely rotating electromagnet. Its working principle is the same as today's reaction stepper motor, and it also depends on the variation of the air gap permeability to produce the electromagnetic torque. At the beginning of this century, The development of the shipbuilding industry is pretty fast as the capitalist powers fought over colonies. In the meanwhile, it makes the technology of stepper motor driver do great progress. After the 80s, the control way of the stepper motor is various because of the emergency of the cheap and multifunctional microcomputer. In the former, the control system of the stepper motor applies a control loop consisting of discrete components or integrated circuits. Not only is it hard to install and adjust, but it also consumes a great number of components and parts. After finishing it, you must redesign the circuit if you would like to change the control scheme. The computer can control the stepper motor by the software, which better fulfills the potential of the motor. Therefore, The computer as the stepper motor controller has become the inevitable tendency and corresponds with the tendency of the digital era.

The differences between the stepper motor and average motor

One of the distinctions between the stepper motor and the average motor is that the stepper motor receives the control of the pulse signal. Stepper motors rely on an electronic switch device called a ring distributor and make the field winding connect to the DC power supply in turn through the power amplifier. Because the excitation winding is arranged in space according to a certain rule, it will form a step-change in the space of the rotating magnetic field to cause the rotor to rotate step by step after the rotating and the DC power supply is connected. With the rise of the pulse frequency, the speed will increase. The rotation of the stepper motor is also related to the number of phases, the number of distributions, and the number of rotor gears.

In addition, the main distinction between the stepper motor and ordinary motor is their form of pulse drive. For this feature, the stepper motor can combine with contemporary digital control technology. But the control precision, the range of speed change, and low-speed performance of the stepper motor are not good as the traditional DC servo motor with closed-loop control. The stepper motor can be used when it requires not very high precision. The stepper motor can exert its features of simple structure, high reliability, and low cost. It can match with the DC servo motor when the stepper motor is suitably used.

The application of the stepper motor

Nowadays, the commonly used stepper motor includes reaction stepper motor, permanent magnet stepper motor, hybrid stepper motor, and single-phase stepper motor. The rotor magnetic circuit of the reactive stepper motor is made of soft magnetic material. The stator has multiphase excitation windings, which generate torque by the change of magnetic conductance. At the present stage, the reactive stepper motor obtains the most application.

The stepper motor is widely applied to various fields of production and practice. The biggest application is the production of numerical control machine tools. Because it doesn't need the transition of A/D and can directly transform the digital pulse signal into the angular rotation, people think it's the idealist executive component of the numerical control machine tool. Besides the application of the numerical control machine tool, the stepper motor can also be used for other machines, such as the nema for the automatic feeding machine, the motor for the common floppy drive, and the printer and plotting instrument.


The stepper driver plays an important role in the digital manufacturing era through its obvious features. With the development of distinctive digital technology and the improvement of its own technique, the stepper motor will be used in more fields.

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