A control system moves an inductively controlled multi-phase motor in a forward or reverse direction. The motion may be in steps or it may be a continuous rotation. A microprocessor under the control of a ROM operates through an integrated input/out device to provide control signals for the motor....http://www.google.ca/patents/US4172990?utm_source=gb-gplus-sharePatent US4172990 - Control system for inductively controlled multi-phase motor
