Abstract: A back EMF controlled, synchronous, permanent magnet motor capable of extremely high rotation speeds at high efficiency. The motor includes a permanent magnet flux source and excitation coils for producing a rotating magnetic field mounted on an iron free form to substantially eliminate core loss and resulting rotor drag. Back EMF is determined directly from the excitation and controls the excitation to produce a torque angle of substantially 90.degree. between the magnet and coil fluxes. Coil excitation is used at maximum efficiency and hunting is avoided. The permanent magnet provides a high flux density that also allows a low current in the motor coils and thus reduces coil copper losses to further improve efficiency.

Abstract: A control system regulates operation of an electrical motor having multiple stator and rotor coils by regulating the phase displacement (1) between the rotor and stator energizing signals, (2) between the signals passed to the individual rotor coils, and (3) between the signals passed to the individual stator coils. A recorder coupled to the lines over which the phase-regulating signals are supplied to the rotor and stator coils can record these signals for later application to the motor to repeat the initial movement. Additionally displacement of the motor shaft produces signals which can be recorded for later duplication of the original shaft displacement. The phase-regulating signals for the rotor and stator coils can be supplied from a variable frequency oscillator, or a data processor, or any other suitable source.

Abstract: Capacitive phase shift circuitry for supplying current to the two coils of a synchronous motor at a desired voltage and phase relation, without the need for a voltage drop resistor.