Glossary · Motion control and drives
Driver (motor)
Also known as: Motor driver, Stepper driver, Amplifier
German: Treiber
In motion control, a driver is the power electronics stage that converts low-power command signals, such as step and direction pulses, into the currents that drive a motor's windings. The term is used especially for stepper motors and small drives.
- Motion control
In one sentence
A motor driver is the power electronics stage that turns command signals such as step/direction pulses into motor winding currents.
Example
A labeling machine's stepper motor is connected to a microstepping driver that receives step and direction pulses from the PLC.
How it applies
- Engineering: Drivers are selected by motor current, supply voltage and command interface (step/direction, analog, fieldbus). Microstepping settings determine resolution.
- Commissioning: Current settings, microstep resolution and idle current reduction are often set with DIP switches or software and must match the motor.
- Operation: Simple drivers have no position feedback; lost steps go unnoticed unless an encoder is added.
- Documentation: Distinguish the hardware driver from a software device driver, which the German term "Treiber" also covers. In installation instructions, document switch settings in a table and show the wiring of the command interface.
Driver vs. servo drive
A driver in the narrow sense amplifies commands without closing a position or velocity loop. A Servo drive closes current, velocity and often position loops using feedback. Manufacturers sometimes call servo drives "servo drivers", so check the function, not the name.