How are Stepper Actuators Controlled?

Linear Stepper actuator motors are typically controlled by a driver and controller. The amount, speed, and direction of rotation of stepper actuator motors are determined by the configuration of digital control devices. The main types of control devices for stepper actuator motors are: stepper actuator motors control links and stepper actuator controllers.

Linear Actuators – Category Shot
Type of Stepper Actuators

There are three basic types of stepper actuators. The stepper actuator motor types vary by their construction and in how they function. Each type of stepper actuator offers a solution to an application, in different ways. The three basic types of stepper actuators include the Variable Reluctance, Permanent Magnet and Hybrid Actuators.

Variable Reluctance (VR) Stepper Actuators

VR stepper actuators are known for having soft iron multiple rotors and a wound stator. The VR stepper actuators generally operate in step angles from 5 to 15 degrees, at relatively high step rates. They also possess no detent torque. In Figure 5, when phase A is energized, four rotor teeth line up with the four stator teeth of phase A by magnetic attraction. The next step is taken when A is turned off and phase B is energized, rotating the rotor clockwise 15 degrees; Continuing the sequence, C is turned on next and then A again. Counterclockwise rotation is achieved when the phase order is reversed.

Permanent Magnet (PM) Stepper Actuators

Linear Actuators – Type – PM Non-CaptivePermanent Magnet Stepper Actuators differ from variable reluctance stepper actuators by having permanent magnet rotors with no teeth. These rotors are magnetized perpendicular to the axis. When the four phases are energized in sequence, the rotor rotates as it is attracted to the magnetic poles.

Linear Actuators – Type – Hybrid Non-Captive
Hybrid Stepper Actuators

Hybrid Stepper Motor Actuators combine qualities from the both permanent magnet and variable reluctance stepper actuator motors. The Hybrid stepper actuator motors have some of the desirable features of each. These stepper actuator motors have a high detent torque, excellent holding and dynamic torque, and they can operate in high step speeds. Step angles of 0.9 to 5.0 degrees are normally seen in hybrid stepper actuator motors. Bipolar windings are generally supplied to these stepper actuator motors, so a single power supply can be used to power the stepper actuator motors.