Patent ID: 7633260

Claim:
An apparatus for controlling the starting and stopping of an AC induction motor, the apparatus comprising: a first magnetic permeable portion having first, second and third legs; a second magnetic permeable portion arranged relative to the first magnetic permeable portion such that a magnetic control flux of the second magnetic permeable portion has an opposite magnetic polarity to a magnetic control flux of the first magnetic permeable portion, the second magnetic permeable portion having fourth, fifth and sixth legs; a non-magnetic spacer separating the first and second magnetic permeable portions to prevent magnetic control flux cancellation between the first and second magnetic permeable portions; a first AC power phase winding wound around the first and fourth legs; a second AC power phase winding wound around the third and sixth legs; a first pair of DC excitation control windings mounted around the first magnetic permeable portion; and a second pair of DC excitation control windings mounted around the second magnetic permeable portion; wherein a magnetic power flux opposes the magnetic control flux in the first magnetic permeable portion and a magnetic power flux assists a magnetic control flux in the second magnetic permeable portion during a first half cycle, and a magnetic power flux assists a magnetic control flux in the first magnetic permeable portion and a magnetic power flux opposes a magnetic control flux in the second magnetic permeable portion during a second half cycle, such that the impedance of the AC power phase windings is changed by an equal and symmetrical variation of the density of the combined magnetic fluxes in each of the magnetic permeable portions during a complete power cycle to produce a balanced voltage with a symmetrical waveform from each of the AC power phase windings.