Two-Speed Single-Winding Shaded-Pole Single-Phase Induction Motors

A two-speed single-winding single-phase induction motor based on the shaded-pole concept is developed, using pole- amplitude modulation logic, with only four terminals taken out from the winding. A tremendous improvement in the performance of the machine is shown to be possible when the shading winding is short circuited through a phase-shifting device. An economical value for the ratio of the shading to main winding turns, which has been known to be theoretically possible, is experimentally verified.