The asymmetrical stator as a means of starting single-phase induction motors

THE shaded-pole motor is quite simple to construct; but for all but the smallest sizes, losses are large; and if distributed windings are used, its construction becomes more complicated. A single-phase induction motor may be given starting torque by varying the rotor constants over the pole face, either by asymmetrical iron structure or winding. Starting torque is comparable with that of a shaded-pole motor, and construction is very simple with nothing to get out of order. The chief drawback appears to be the smaller power factor which is due to reduced mutual inductance.