Abstract: A fabric washing machine includes a container to receive fabrics and fluid to wash the fabrics. A switched reluctance motor is operatively connected to oscillate and rotate the container. A control operates the machine by providing commutation signals to the motor to energize the stator phases in a predetermined sequence as corresponding rotor phases approach the stator phase being energized. To stop the machine the control repeatedly senses the instantaneous alignment of the stator and rotor phases and supplies commutation signals to the motor to energize the stator phases in the same sequence but as corresponding rotor phases have become aligned with the stator phase being energized.

Abstract: A speed control circuit for triggering a motor, of the kind having a winding arrangement with multiple taps, comprises a plurality of electrical sources and a switching network coupled between the plurality of electrical sources and the taps of the winding arrangement. The switching network has selectively operable switches, for example, electronically controllable switches, for connecting more than one of the electrical sources to any one of the taps at the same time. A commutation controller is coupled to each of the electrical sources and each of the switches for operating the switches and the electrical sources. A feedback circuit provides information to the commutation controller with respect to the rotational speed and phase of the motor. The electrical sources may be arranged into groups, for accelerating and decelerating the motor.

Abstract: An apparatus for controlling conditions in response to an operator input, the apparatus including a rotary knob coupled to the shaft of the rotor of a stepper motor having first and second stator windings, in quadrature, with each winding being center tap grounded to provide first and second winding portions for each winding. One pair of first winding portions are used for providing pulse inputs to a microprocessor on rotation of the knob, in either direction, via a pulse control system, with the microprocessor providing command signals to a braking control system, which includes a direct current power control source, which may be either a voltage or current control source. The power control source, in turn is in circuit relation with the pair of second winding portions.

Abstract: This invention relates to an inverse electromotive force eliminating device which protects a motor controller of a motor utilizing a MOS-FET by effectively eliminating the inverse electromotive force generated in a process for accelerating and decelerating a mobile device by utilizing an alternating current servo motor operated by applying the power supply of an inverter. A voltage, generated by an inverse electromotive force upon accelerating and decelerating of a motor in a state when the direct current required for circuit operation is supplied by power supply, increases at an input of an inverter. The voltage is detected by an inverse electromotive force detector and thereafter it is applied to an inverse electromotive force eliminator by utilizing a MOS-FET base driver so that the inverse electromotive force of motor is eliminated. Simultaneously, first and second indicators indicate whether the power supply is inputted and whether the inverse electromotive force is generated.

Abstract: A device for braking a rotating magnetic disk in a magnetic storage system senses a back EMF generated by a drive spindle motor. By electrically shorting the coils in the drive spindle motor the rotation of the magnetic disk is stopped. The back EMF is compared with a reference voltage. The reference voltage is selected so that the rate of rotation of the magnetic disk is large enough that a magnetic head "flies" over the surface of the disk, but small enough so that surge currents in the drive spindle motor will not damage the motor coils. Field effect transistors are used to electrically short the coils. A holding capacitor holds a voltage on the gates of the FETs upon loss of power to the magnetic storage system. A reset circuit draws charge from the holding capacitor upon power-up of the storage system.

Abstract: An electric motor has first, second and third stator windings supplied by a source of alternating voltage having three phases A, B and C, respectively. A separate thyristor switch assembly couples each stator winding to an alternating voltage phase when said switch means is rendered conductive by a trigger signal. When the speed of the motor is above a first predefined level, the thyristor switch assemblies are triggered, in response to the polarity of the voltage between phases A and B being opposed to the polarity of back emf voltage induced across the third winding, to apply current through said first and second stator windings. However, when the speed of the motor is below the first predefined level, the thyristor switch assemblies are triggered, in response to the polarity of the voltage betwen phases B and C being opposed to the polarity of back emf voltage induced across the third winding, to apply current through said second and third stator windings.

Abstract: A system for controlling a pulse-driven dc motor includes a pulsed grounding switch, an inductor connected between the pulsed grounding switch and the armature of the dc motor, and a tracking circuit connected across the inductor. The control system further includes a variable resistor that provides a series path through the inductor for dissipating generated armature current from the motor. In operation, the resistance provided by the variable resistor depends upon the counter emf generated by the motor and upon transient voltages induced across the inductor when the pulsed grounding switch is periodically opened and closed. More particularly, the variable resistor provides minimal resistance when the back emf of the motor is low and provides increasing resistance as the back emf of the motor increases.

Abstract: An electric motor is braked by applying pulses of current to a winding of the motor creating a negative torque which slows the motor. In order to detect when the motor has stopped and as a consequence, when to discontinue applying the current pulses, a periodic determination is performed as to whether the back emf voltage induced in a winding of the motor is within a range of defined values, such as between a positive reference voltage level and a negative reference voltage level. The application of pulses of current is terminated a given interval from when a predetermined number of consecutive determinations all indicate that the back emf voltage is within the range. The length of the given interval is derived from the amount of time between when the electricity began to be applied to brake the motor and the occurrence of the predetermined number of consecutive determinations.

Abstract: An electric motor is braked by sensing the polarity of voltage of the alternating electricity for powering the motor and sensing the polarity of the voltage induced in the motor by the back electromotive force. When these polarities are opposite the electricity is applied to the motor to generate a braking torque. The application of the electricity is stopped a given interval after it begins to be applied during consecutive voltage cycles. This interval is derived from the time period between when braking commenced to when the electricity was applied during consecutive cycle.

Abstract: A digital robot control is provided with cascaded position/velocity and torque control loops with microprocessor servo controllers in each. The servo controller includes two microprocessors that operate as a servo engine in providing motion control for six robot axes. One microprocessor is structured to perform data processing and coordination tasks. The other one performs calculation tasks and operates as a slave processor to the first.

Abstract: An industrial robot comprising an industrial robot main body, detectors for detecting a relative position between movable members of the robot main body, a designation circuit for designating position signals from the detectors upon a teaching operation, memory for sequentially storing the position signals designated by the designation circuit, digital interpolation circuits for executing interpolation based on at least four read out position signals from the memory in order to determine the required number of desired positions on an area delineated by lines joining points corresponding to the four position signals, and servo circuits for positioning each of the movable members of the robot main body while using a calculation result signal from the digital interpolation circuits and the position signals from the detectors upon a playback operation.

Abstract: A braking method for DC motor of the present invention is applied to a pulse-driven DC motor. A counter electromotive force of reverse polarity to driving pulses which is generated by induction at the winding of the DC motor is charged in a capacitor. The charged counter electromotive force is fed to the winding of the DC motor during the time that the driving pulses are not fed to the motor, so that plugging is applied to the DC motor. Thus, an external power source for plugging is not necessary, and power consumption is reduced and the construction of the braking circuit becomes very simple. Also, the driving period and the plugging period have a complementary relationship therebetween, thereby enabling the accurate controlling of the rotational speed of the DC motor with a very simple circuit.

Abstract: A motor control circuit for submersible pumps has features to prevent restarting while the electric motor is backspinning. The circuit includes a sensor for sensing the voltage produced by the residual magnetism in the rotor of the motor while it backspins. The voltage sensed is amplified, then rectified and compared with a reference voltage that is preset. The reference voltage corresponds to a voltage produced during backspinning at a selected maximum amount tolerable when restarting. The DC pulses are filtered to provide a corresponding voltage, then compared to the reference voltage. The control circuit is disabled from allowing a restart, either manual or automatic, when the corresponding voltage is greater than the reference voltage.

Abstract: A shorthand machine including an electric drive system to advance the platen. In accordance with the invention, the platen can be advanced in a fully mechanical, conventional mode, fully electric mode, or by a combination of electric and mechanical drives. In the electric or electric/mechanical modes, after the shorthand machine operator makes a key stroke and releases the keys, an electric circuit pulses an electric motor connected to the platen to drive the platen for a predetermined duration of time. Subsequent to the driving pulse, power to the motor is reversed to quickly brake the motor and bring it to a rapid stop. The duration of time that the motor is activated may be varied, varying the amount of advancement of the platen, and thus varying the distance between received key strokes for each word or part of word generated by the operator of the shorthand machine.

Abstract: During the positioning of a dc stepper motor equipped with a permanent magnet rotor and electronic commutation device, an additional braking moment is enabled through a time delay stage which is triggered by the commutation signals, and/or the desired value of the nominal current regulator current is reduced to a desired holding current value at the end of the delay of the time delay stage.

Abstract: An electric nutrunner for tightening bolt joints to a desired tightening torque. The nutrunner utilizes a motor having a low moment of inertia and a control device that supplies a pulse to the motor as an indication that the nut-tightening is to be terminated, thereby braking the motor electrically.

Abstract: An armature of an electric motor for an elevator car is controllably driven by a three-phase source through a semiconductor converter controlled with a difference between a command and an actual car speed signal. A relay for sensing a ripple current from the converter is serially connected to a tuned filter across the armature. When a break occurs anywhere in a circuit with the motor armature, the sensor relay is deenergized and connects an emergency braking circuit across the armature. Alternatively the sensor relay may be connected via the filter to a reactor connected to the converter.