Speed control circuit for AC or three-phase motor - can connect stator winding directly to power supply or can connect it to braking circuit

摘要

The circuit has a comparator for comparison of nominal and actual speeds of the motors and has a phase shifting control for motor supply. The comparator together with a brake voltage control stage and an overcurrent control stage is connected to the phase shift control. The control system is individually connected to a switching device by which the stator winding can be connected either directly, or together with a braking circuit to the supply power stage.