Abstract: A speed control apparatus for a synchronous motor is provided with a resolver fixedly connected to a rotor of the motor, which produces a phase modulated signal corresponding to an angular position of revolving magnetic field in the motor, a circuit for converting the phase modulated signal into a rotational speed signal of the motor, a phase compensation circuit for advancing in phase a reference signal in accordance with the rotational speed signal, a multiplier for multiplying the phase modulated signal and a rotational speed instruction signal, a synchronous rectifier for synchronously rectifying the output of the multiplier by an output of the phase compensation circuit, and a current control loop circuit for receiving an output of the synchronous rectifier and for producing a signal having a phase angle delayed as much as the phase angle is advanced in the phase compensation circuit.

Abstract: A pulse generator includes a transducer such as a resolver coupled to a driven body for converting a mechanical motion thereof to a phase-modulated signal, an excitation signal generator for supplying an excitation signal as a carrier of the phase-modulated signal to the transducer, a clock pulse generator for generating a train of clock pulses, a waveform shaping circuit for shaping the waveform of the phase-modulated signal issued from the transducer, a counter for receiving the clock pulses to form a content of count representing a time interval by which the output from the waveform shaping circuit being in a high or low logical state is longer or shorter than the corresponding period of the excitation signal, a count pulse generator for generating count pulses, a gate circuit for allowing the count pulses to enter the counter until the counter having contents of count corresponding to the time interval is initialized while the output from the waveform shaping means is in its a succeeding low or high logic

Abstract: A resolver type motor speed control arrangement including an exciting signal generating circuit including a first frequency division counter for producing from a clock pulse an exciting voltage signal supplied to the primary winding of the resolver coupled to the motor, reference signal generating means in the form of a up-down counter for generating a reference signal having a predetermined period from the clock pulse, circuit means for supplying a feed pulse to the reference signal generating means for varying the phase of the reference signal, phase detecting means for synchronously rectifying the output signal of the secondary winding of the resolver in accordance with the reference signal, speed signal generating means for generating a speed signal corresponding to the speed of the motor or the resolver and a servo-amplifier responsive to outputs of the phase detecting means and the speed signal generating means.

Abstract: In a speed control system of a three phase induction motor, a resolver is connected to the rotor of the motor for producing a phase modulated signal Esin (.omega.t+.theta.) containing the rotational angle .theta.. This signal is converted into a speed signal K.sub.2 E(d.theta./dt) which is compared with a speed instruction signal to produce an error signal. The error signal is multiplied with the phase modulated signal and the product is rectified with three synchronous rectifier units respectively controlled by three reference signals having phase differences of 0, 2.pi./3 and 4.pi./3 for producing three phase voltages applied to the stator winding of the induction motor. The control system enables to control the speed while maintaining the slip frequency at a constant value.

Abstract: A velocity detecting apparatus using a resolver, and more specifically, a two-phase resolver which rotor is connected to a rotary drive means such as a motor, a source for exciting the primary windings of the resolver, a wave shaper which produces a square wave of the same period and phase as the output signal produced by the secondary windings of the resolver, a phase discriminator which rectifies the output signal of the wave shaper, a low pass filter for producing a triangular wave from the output signal of the phase discriminator and a circuit for producing a signal corresponding to the absolute value of the slope of the triangular wave.

Abstract: Control system for driving a synchronous motor at a speed greater than a rated speed with a rotational speed detector for the rotor mounted on the motor, rotational position detector for detecting the rotational position of the field pole of the motor, an error signal generator which produces the difference between a desired speed signal and an actual rotational speed signal, and a calculating device for calculating armature current component values Id, Iq and power-factor .phi..