Abstract: An energy economizing AC power control system for energizing the stator windings of a three phase induction motor comprises an AC generator connected to the motor rotor shaft for generating an AC signal that is frequency modulated in response to load induced speed variations of the rotor, a variable resistance whose magnitude is responsive to the frequency modulated signal, an AC power proportioning switch which produces a single phase output consisting of pulses whose widths vary with variations in the magnitude of the variable resistance, a single phase-to-three phase converter coupled to the output of the proportioning switch for producing three control signals that occur respectively at the frequency of and during each voltage phase alternation of a three phase sine wave power supply, and three solid state switches that are respectively controlled by said control signals for controlling the time duration that each alternation of the three phase power supply is coupled via an associated one of the solid st