The stator is equipped
with 2 windings spatially displaced by 90o : the main winding is
directly connected to the single-phase ac supply; the auxiliary winding is
connected via a capacitor to the supply. The current in the auxiliary winding
will thus lead (in time) the current in the main winding. As a consequence, a
rotating field is produced to cause the starting of the motor. When the motor
reaches a prescribed speed, the start capacitor in the auxiliary winding is
disconnected by means of a centrifugal switch. The motor now runs under the
action of the main winding and the auxiliary winding connected to the small run
capacitor (in some designs, this capacitor is removed). The animation
illustrates this starting process.