Abstract: A method for controlling a reversible polyphase rotating electrical machine, wherein at least one coil circuit is supplied through a bridge of switches, including the following steps: controlling (P1) the bridge to deliver to the coil circuit a periodic voltage with a phase shift (d) relative to an electromotive force induced in the coil circuit, such that an operating torque is generated, the phase shift having initially a first value (d0); controlling (P2) the bridge to deliver to the coil circuit a periodic voltage with the phase shift (d) producing a torque ranging between the operating torque and the opposite of the operating torque, the phase shift taking on a plurality of values upon the control; flipping (T2) the bridge in rectifying mode.

Abstract: A method for controlling a reversible polyphase rotating electrical machine, wherein at least one coil circuit is supplied through a bridge of switches, including the following steps: controlling (P1) the bridge to deliver to the coil circuit a periodic voltage with a phase shift (d) relative to an electromotive force induced in the coil circuit, such that an operating torque is generated, the phase shift having initially a first value (d0); controlling (P2) the bridge to deliver to the coil circuit a periodic voltage with the phase shift (d) producing a torque ranging between the operating torque and the opposite of the operating torque, the phase shift taking on a plurality of values upon the control; flipping (T2) the bridge in rectifying mode.

Abstract: A method and apparatus to automatically reverse the motor of a power tool, such as a dispensing gun or similar tool. In some constructions, a controller automatically reverses the direction of plunger movement and removes the plunger from contact with the back wall of a cartridge. The controller has a trigger switch that is coupled to a power source, such as a battery, and includes a main power on/off switch and a potentiometer. A protection or secondary switch is coupled in parallel to the main power on/off switch. A power supply circuit and a commutator are each coupled to the main and secondary switches. An overload sensor is coupled to the commutator. The controller includes a programmable device that is coupled to the power supply circuit, the potentiometer, the commutator, and the overload sensor.

Abstract: An interface circuit for actuating an electrical consumer, especially a pole-changing rotary-current induction motor, with a first contact element assigned to a signal line carrying an alternating voltage signal to generate at least two different control signals. A circuit arrangement is provided for actuating an electric motor, especially a pole-changing rotary-current induction motor, with a control switch element having an aforementioned interface circuit, which is connected via a signal line to a motor control of the electric motor.

Abstract: In an electric motor-driven power steering apparatus which comprises a bridge circuit for connecting a power source between input terminals and also connecting an electric motor between output terminals and energizes the electric motor by this bridge circuit and operates electric motor power to a steering system, the bridge circuit includes a predetermined number of arms constructed by connecting circuits for connecting switching elements in parallel with diodes in series so that the diodes mutually become reverse polarity.

Abstract: A method and circuit for controlling motors utilizing a multiple-phase sinusoidal signal generator (80) with control inputs (71,72,76) for determining motor (84) speed and direction. The multiphase sinewave generator has a synchronous-digital state machine (70) that provides a plurality of analog signals (1A-12A) having phase-shifted waveforms. A resistive-ring network (30) and instrumentation amplifiers (31) shapes the plurality of analog signals to provide a multiphase set of sinusoidal signals (77). Automatic-motor-control systems modify control-inputs (71,72,76) into the multiphase generator (80) based on feedback (105,86) to control motor (84) speed and direction.

Abstract: First FET power transistors of first power amplifying parts and second FET power transistors of second power amplifying parts form current paths from a DC power source to three-phase windings. Three-phase first amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the first power amplifying parts. Three-phase second amplified current signals varying smoothly in rising and falling slopes are supplied to conduction control terminal sides of the second power amplifying parts. A switching control part performs simultaneous on-off switching of the conduction control terminal sides of the first power amplifying parts, thereby causing first FET power transistors of the first power amplifying parts to perform high-frequency on-off switching. As a result, three-phase drive currents to the windings vary smoothly, thereby reducing motor vibration.

Abstract: Control device responding to current changes in a load circuit including a supervisory circuit carrying a current proportional to the current in the load circuit, a transformer coupling the supervisory circuit to the load circuit, and an overcurrent sensor and an overcurrent relay electrically connected in series in the supervisory circuit. The overcurrent sensor being set to deliver a signal when a given first current value is reached after a response delay, the overcurrent relay being able to interrupt the load circuit if a given second current value is reached after an adjustable response delay, and a method of operating the control device in a waste crushing machine.

Abstract: A hammer drill having a bypass switch which is activated by the selector ring to prevent the drill from operating in the hammer mode by shunting the reversing switch. This is a precaution to prevent damage to the clutch teeth which are designed for ratchet action when the tool is operated in the forward direction, but will lock down in reverse to stall tool or damage the mechanism. In the drill mode, the bypass switch connects the reversing switch in circuit with the on-off switch.

Abstract: A hoisting apparatus and a control circuit therefor comprising a reversible electric motor drivingly connected to a hoisting drum for hauling an object up and down. The control circuit includes first and second photosensitive elements each responsive to a light beam for initiating rotation of the electric motor in either direction and means for terminating rotation of the electric motor.

Abstract: Safety apparatus for use with a three-phase AC hoist motor adapted to be connected to a three-phase AC power source, motor rotation being correct if the motor is connected to the source in correctly phased relationship but incorrect if connected with an incorrectly phased relationship.Phase detection circuitry is provided for detecting the phase relationship of said AC power provided by the power source connection and for providing a signal indicative of an incorrect phase relationship. Phase corrector circuitry of the apparatus is operative when enabled for correcting the phase relationship of the AC power provided from said source to the motor. Circuitry is included for functionally interconnecting the phase detector circuitry and the phase corrector circuitry for enabling operation of the latter in response to said signal, thereby ensuring operation of the motor in a correct direction regardless of incorrect phasing provided by the connection to the power source.

Abstract: The power contactor for controlling the application of power to and the character of the current to a load includes a power relay having contacts connected between a source of power and the load, such as a motor or heater, with each of the contacts being provided with arc suppression means. A steering relay is provided to control the direction of current to a motor and thus its direction of rotation or the voltage applied to a heater. A control circuit insures that the steering relay contacts remain either open or closed while power is being applied to the load. The steering relay is provided with bracer bars to prevent short circuiting between relay contacts should any welding occur therebetween. The arc suppression means for each of the power relay contacts includes a solid state device, such as a triac, in parallel therewith, and auxiliary contacts for controlling the gating current to the triac.

Abstract: A valve operator circuit normally operates to compare the pulse rates of two trains of pulses and to step an associated valve open or closed depending on which of the two pulse rates is the higher. The circuit includes a manually-operated presetting arrangement which, when operated, causes the normal pulses to be inhibited from moving the valve, and causes the valve to move to a desired position.

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.