Starting winding disconnection circuit for AC motor - has time delay circuit forming source of triggering current for gate closing power terminals switch

摘要

The a.c. motor has main and starting windings. The main winding is connected in parallel to the main supply. The circuit comprises a pair of power terminals and a gate which closes the switch in response to a triggering current. The power terminals are in series with the starting winding but in parallel with the main winding. A time delay circuit (21) is connected with the gate (19) and forms a source of triggering current. An auxiliary coil (31) is wound on the stator, so that a voltage is induced in it. This coil is connected to the delay device and operates it for the triggering current delivery during a specified time interval after the initial energy supply to the motor.