Types of Stepper Motors

Electronics & ElectricalElectronDigital Electronics

A stepper motor is an electromechanical energy conversion device which converts electrical input power into mechanical output power. Basically, it is a brushless motor that can divide a full rotation into an equal number of steps and the operation of the motor can be accurately controlled with no-feedback system when the motor is properly sized to the application.

Practically, the stepper motors are manufactured in sizes ranging from milli-watts to hundreds of watts and the maximum torque values upto 15 N-m and the step angle from 1.8° to 90° mechanical.

Types of Stepper Motors

Depending upon the rotor arrangement, the stepper motors are of three types viz −

  • Variable reluctance (VR) stepper motor

  • Permanent magnet (PM) stepper motor

  • Hybrid stepper motor (combination of VR and PM stepper motors)

Advantages of Stepper Motors

The chief advantages of the stepper motors are given as follows −

  • Stepper motors have longer life.

  • Stepper motors have high holding torque.

  • Stepper motors have a low maintenance cost.

  • Stepper motors produce high torque at low speed.

  • Stepper motors operate on an open-loop system and do not require an encoder, this makes the stepper motor less complex and inexpensive.

  • The rotation angle of the stepper motor is proportional to the input pulse.

  • Stepper motors have excellent response to starting, stopping and reversing.

Disadvantages of Stepper Motors

Stepper motors suffer from the following disadvantages −

  • With the increase in the speed of the motor, the torque of the stepper motor starts to decrease.

  • Stepper motors take a much larger current, which makes them less efficient.

  • There is no feedback used in the stepper motor which indicates to the missed steps.

Applications of Stepper Motors

The stepper motors have a wide range of applications. Stepper motors are digitally controlled motors, hence, they are more suitable for use with the computer controlled systems. Some of the applications of the stepper motors are given as follows −

  • Stepper motors are used in numeric control of machines tools.

  • They are used in tape drives and floppy disc drives.

  • They are used in printers and X-Y plotters.

  • They also find application in robotics, textile industries, integrated circuit fabrication and electric watches etc.

  • Stepper motors are also used in space crafts launched for scientific explorations of planets.

  • Stepper motors are used in the production of science fiction movies.

  • Apart from the above applications, the stepper motors are also used in commercial, medical and military applications and will be increasingly used in future.

  • Stepper motors are used in automotive gauges and automated production devices.

  • Stepper motors are used in medical scanners, samplers, digital dental photography, respirators, blood analysis machinery and many more medical applications.

  • Stepper motors are used in digital cameras for automatic focus and zoom functions

Published on 24-Sep-2021 05:58:26