Motor speed can be regulated in various ways depending on the cost and performance requirements of the final application:
- Bi-directional drives
When a motor with a permanent phase-shift capacitor is used, the direction of rotation can be reversed by means of two AC switches connecting the phase-shift capacitor in series with either of the two stator windings.
- Phase-controlled drives
ST offers a silent and cost-effective variable speed drive with an innovative topology to control motor speed. A simple phase-control switch is used to vary speed by changing the motor torque.