Abstract: A D.C. motor control circuit including a wheatstone bridge type speed regulating circuit with a transistor arranged for detection of the counter-EMF developed across the motor armature to control operation of a drive control circuit. In one embodiment of the invention, an actuating circuit comprises a constant voltage source formed from a constant current circuit connected parallel to an electrical power supply source for the motor and a variable resistor connected in series to the constant current voltage source. A diode applies the output of the variable resistor to the base of the transistor to thereby effect conduction of this transistor.

Abstract: This specification discloses a Hall motor control system in which Hall elements detect the position of a rotor comprising a permanent magnet to switch over driving currents flowing to driving coils. Induced voltages produced in the driving coils or the voltage detecting coils by rotation of the motor are synthesized by a diode, and the resultant voltage is level-shifted by a level shift circuit including a transistor, and then compared with a reference speed voltage. To control the input to the Hall elements by the comparison output and provide a constant speed of rotation, there are provided temperature compensating means formed by diodes in the base circuit of the transistor of the level shift circuit and in the reference speed voltage circuit, respectively.

Abstract: A DC motor is controlled by a Hall generator provided in a control circuit which detects the voltage equivalent to the terminal voltage of a driving means connected to the flux-producing windings positioned in torque-producing relation to the rotor, and regulates to always keep the terminal voltage of the driving means constant.

Abstract: An object of the present invention is to provide a comparator circuit for a control circuit of a Hall motor having a compensation function for correcting variation in reference voltage and in temperature and power source voltage, etc. by impressing an induction voltage which corresponds to the rotation speed of a motor and a reference voltage which corresponds to the reference number of rotation to the both input terminal of a differential type circuit in a control circuit for a Hall motor.

Abstract: A speed regulation system for DC motors of the type comprising a rotor having magnetic poles of opposite polarities, a stator having at least one pair of flux-producing windings positioned in torque producing relation with the rotor, and Hall generators positioned in fixed relation to the stator and angularly spaced apart from each other in magnetic relation to the rotor so as to sense the magnitude of the rotor flux density as a function of the angular position of the rotor. The speed regulation system comprises a circuit for detecting the frequency of the output signals of the Hall generators so as to generate the pulse signals representing the peak values of the output signals, a phase shifter for shifting the phase of the pulse signals, and a wave shaping circuit for generating the signals with a desired waveform in response to the output signal of the phase shifter.

Abstract: A driving system for reversibly rotating a D.C. brushless motor is disclosed. The system comprises Hall generators for detecting positions of a rotor, and a drive circuit for controlling conduction and interruption of current applied to stator windings making use of output of said Hall generators. The system further comprises an inversion control circuit including a switch for reversibly switching polarities of an applied power source in order to reversibly rotate the D.C. motor thereby reversibly inverting the D.C. motor in response to signals from the power source whose polarities vary alternately.

Abstract: A speed control apparatus for use with a brushless direct current motor having Hall elements, which permits the associated motor to quickly regain the reference speed, or permits more uniform speed control of the motor than was conventionally possible.

Abstract: A system is provided to synchronously operate a DC motor in response to the frequency of a reference signal. The system includes a first feedback loop having a reference signal generator, a speed signal generator in relation to speed of the motor, and a flip-flop circuit for producing a rectangular wave pulse for supplying to the DC motor current corresponding to a phase difference between two signals from these generators. The system further includes a second feedback loop for speed control having a forced synchronization circuit which processes the output of the speed signal generator and brings the motor speed into a synchronization condition in order to prevent the motor from erroneously synchronizing.