 The motor continues to increase its speed until the motor torque and the load torque balance each other and a steady speed is achieved.At this stage switch 2 is opened and momentarily the motor is supplied by even lower voltage, because the windings of the autotransformer act as inductors connected in series with motor.This time is short - just enough to disconnect the switch 1 and engage switch 3, which connects the full voltage to the motor.