Can I vary the speed of my motor with a variable transformer?

Submitted byglx25v onFri, 08/17/2018 - 17:29

Many motors can use a variable transformer for speed control.

Motors that usually can be controlled by varying the motor voltage:

Universal Motors

Series Wound Motors

Torque Motors

Shaded Pole Motors

Motors that sometimes cannot be varied by changing the motor voltage:

Split Phase Motors

Permanent Split Capacitor Motors

Repulsion Induction Motors

Motors with centrifugal switches

Motors with fan cooling can sometimes be damaged due to the decreased cooling effect at lower speeds (depending on load).

We recommend that the motor manufacturer be queried to determine whether varying the voltage can control your particular motor.