Abstract: A motor that includes a stator that contains a first winding and a second winding driven by alternating currents. The rotor is arranged to rotate relative to the stator and contains a third winding and a fourth winding for generating a magnetic field with an amplitude and a phase angle relative to the alternating currents in the first and second windings of the stator. The motor includes a circuit in communication with the third and fourth windings for controlling the phase angle of the magnetic field and generating a rotating magnetic field that is in phase-lock with the alternating currents in the first and second windings of the stator. The motor also includes a control circuit and a comparator. The control circuit has an angular position feedback device for measuring the phase of the stator and the angular position and velocity of the rotor.

Abstract: A direct current motor for use in a closed-loop control system is disclosed that produces a time varying signal indicative of a position of the motor. An embodiment of the motor includes a rotating commutator having a plurality of slots, a plurality of windings, the number of windings corresponding to one more than the number of slots of the commutator, and a plurality of brushes that are configured so that application of a direct current voltage across the brushes causes the commutator to rotate.A closed-loop control system is also disclosed that includes a direct current voltage source, a direct current motor in accordance with the present, a motor position signal source that generates a motor position signal for rotating the shaft of the direct current motor to a desired position, and a feedback circuit that corrects for any error in the desired position of the shaft of the direct current motor.

Abstract: A direct current motor for use in a closed-loop control system is disclosed that includes a rotating commutator having a plurality of slots, a plurality of windings, the number of windings that conduct current corresponding to one less than the number of slots of the commutator, and a plurality of brushes that are configured so that application of a direct current voltage across the brushes results in a current flow in at least one of the windings which causes the commutator to rotate. Continuous application of the direct current voltage across the brushes causes the current to flow in a varying number of the current conducting windings as the commutator continues to rotate, the number periodically varying from all of the current conducting windings to the at least one current conducting winding.

Abstract: An electric machine system includes a resonant switching system for selecting a resonant frequency of at least a portion of the circuit of the system. The electric machine system includes a first pair of windings for generating force to actuate a moving body and a second pair of windings for exciting the first pair of windings. The resonant switching system includes a resonant inductor and a resonant capacitor. The carrier signal used to excite one of the pairs of windings may have a frequency that is substantially equal to the resonant frequency of the circuit. Preferably, the air gap magnetic flux distribution for the pairs of windings are substantially alike. The electric machine system may employ a rotating body or alternatively may employ a linearly actuating body.