Patent ID: 7663328

Claim:
A multi-phase, multi-frequency controller for an electric motor comprising: a multi-phase signal source providing plural first signals having a constant phase relationship, wherein said first signals have a first frequency; plural mixers coupled to said multi-phase signal source for receiving said first signals and responsive to respective second and third AC signals for combining said first signals and said AC signals to form plural fourth AC signals having a constant phase relationship; plural modulators coupled to said mixers for converting each of said fourth AC signals to a respective fifth pulsed output signal, wherein the pulse width of each of said fifth pulsed output signals represents the phase of respective sixth sinusoidal signals; an amplifier coupled to said plural modulators and to a high DC voltage source and responsive to said fifth pulsed output signals for providing a large AC drive signal to the electric motor; and a feedback control arrangement including variable frequency oscillators coupled to said mixers and to said amplifier and responsive to said large AC drive signal for providing said AC drive signal to said mixers for combining said first signals and said AC drive signal in providing said fourth AC signals.