The Best Way to Control Stepper Motors

An electromechanical device, a stepper motor starts or actuates by electricity. When electric pulses apply to the stepper motor, the shaft rotates through a series of discrete steps, each of a precise angle.

Control

The best way to control a stepper motor is with a microprocessor-based indexer, or controller, used on its own or connected to a computer. An indexer provides outputs to a stepper motor, which controls the number of steps per second, direction and other factors.

Open Loop

Accurately control a stepper by what is known as an open loop control system. No feedback on the position of the motor -- and therefore no sensing or feedback devices -- is necessary; the position of the motor can be determined by keeping track of the electrical control pulses.

Applications

Use stepper motors in applications where control of rotation angle, speed and position are critical. Examples include optical scanners, film-processing machines and even the rotisserie of a barbecue.

References

• Solarbotics.net: Stepper Motor Basic
• Advanced Micro Systems: Stepper Motor System Basics
• Engineers Edge: Stepper Motor Application and Operation