Abstract: A pulse controller for controlling the energization and regenerative braking of a DC electric motor. An electronic switch connects the motor to a power source during motor driving and controls motor current during regenerative braking, the switch being rendered alternately conductive and non-conductive during both driving and braking and the ratio of conductive to non-conductive periods being controlled. The conductive and non-conductive periods are interrelated such that, regardless of the ratio between the periods, during regenerative braking the switch alternates between its conductive and non-conductive states at a rate sufficient to automatically maintain the generated motor current within desired maximum and minimum limits.

Abstract: A DC motor control circuit for providing improved starting and stopping control is provided. The control circuit includes a DC motor that is driven in response to an operating voltage applied thereto. A shunting element is adapted to define a current path in parallel with the DC motor to selectively shunt the operating voltage applied to the DC motor. A DC supply is provided for producing a DC signal, and a constant voltage supply circuit is coupled intermediate the DC supply and the parallel connection of the shunt element and DC motor to selectively apply a constant operating voltage to the DC motor. A control circuit is provided for coincidentally applying a control signal to the constant voltage circuit and to the shunt element to effect a coincident shunting of the operating voltage applied to the DC motor and a cutting-off of the application of the operating voltage to the DC motor.

Abstract: A garage door opener includes a radio receiver and a push button each operable to initiate a pulse for effecting a switching device which in turn energizes a latching relay. Operation of the latching relay completes an energizing circuit to the appropriate winding of a reversible motor which moves the door toward an open or closed position. A sensing circuit is operable for effecting the reversal of the latching relay to change the direction of motor operation in the event the door engages an object in its path. A foot switch may also be provided for positively sensing an obstacle and reversing the drive motor. A transmitter may be provided with an impulse circuit to limit the duration of the system actuating signal regardless of how long the transmitter push button is depressed.

Abstract: The shaft driven by a reversible motor for opening and closing a door is provided with at least one reflective surface. An optical source/detector senses rotation of the shaft and generates a pulse each time one of the reflective surfaces passes. A programmable counter circuit counts the pulses in one direction when the door is opened and de-energizes the motor when a predetermined count is reached without the use of mechanical switches. The counter is decremented when the door is closed, and de-energizes the motor when the count returns to zero. Any obstruction will cause the system to stop the door if sensed during opening, or to reverse the door's direction if sensed during closing. Provision is made to account for any "coasting" the door may experience due to inertia; and the system will also track and permit small changes in the closed position of the door, as might occur if snow accumulates beneath the door.

Abstract: An electronic speed error signal processing circuit is provided which attenuates rapid fluctuations ocurring in the speed error signal used to control the fluid inlet valve of a fluid driven prime mover. Such fluctuations contribute greatly to valve wear by causing "valve flutter," the continual rapid opening and closing of the inlet valve as the speed control system of a prime mover instantaneously responds to any small speed error signal fluctuation. By attenuating these rapid fluctuations, valve flutter is reduced.

Abstract: A circuit for electronically braking an AC motor. The circuit includes a controlled rectifying means for applying DC to the motor and a control means for turning the rectifying means on after deactuation of the motor for a timed interval determined by the charging rate of a timing capacitor through a variable resistance.

Abstract: The invention provides snubbing apparatus for a D.C. motor in which a capacitor which is charged while the motor is rotating in a first direction is discharged into the gate of a thyristor to initiate the snubbing action. When the thyristor goes on a field coil is connected in series with the motor armature, so as to place the motor in a regenerative mode and snub the motor.

Abstract: A control circuit for an electric vehicle traction motor having separate armature and field windings, includes an armature winding current control, a braking contact which is in series with the armature winding and which is closed or opened in accordance with whether motoring or braking is required, an alternative path being provided for motor current during braking, reversing switch means connected in circuit with the field winding, a field current control and logic circuit means arranged to operate during a change for braking mode to motoring mode so as sequentially to reverse said reversing switch means when the field current is below a predetermined level, commence field current flow in the required direction for motoring and then close the brake contact whereby any residual magnetism in the field structure is reversed before the brake contact is closed.

Abstract: A circuit for the energy-conserving braking of an electrically powered vehicle having a series-wound direct-current motor with field winding and armature connected in series with a high-ohmic resistance across the battery connection is effected by a main thyristor is provided with a second thyristor serving to quench the first thyristor. A capacitor (quenching capacitor) is included in a commutating device or network parallel to the main thyristor. A voltage sensor responsive to the voltage level at the junction between the condenser and the main thyristor controls the commutating circuit.

Abstract: An electric torquing device comprises a d-c. motor for producing an output torque that varies in proportion to variations in the armature current, a power source for supplying d-c. current to the armature to produce an output torque, and regulating means for maintaining the d-c. current at a relatively low level during the run-on stage of a torquing operation. Sensing means responsive to a preselected parameter of the torquing operation, such as the velocity of the motor output, produces a control signal when the tightening stage of the torquing operation begins. Control means responsive to the control signal from the sensing means adjusts the regulation of the d-c. current to maintain the current supply to the armature at a relatively high level during the tightening stage of the torquing operation.

Abstract: A circuit breaker motor operator control circuit utilizes the voltage developed across a dynamic braking resistor during breaking of a permanent magnet DC motor to prevent re-energization of the motor until it has been braked to a virtual stop. The control circuit also includes a timing network operating to prevent continued pumping of the breaker operating mechanism by the motor operator should the operating mechanism for some reason fail to become charged within a prescribed time period.

Abstract: A PNM (pulse number modulation) signal is generated in response to a DC signal the magnitude of which is in proportion to the detected rotational speed of an electric motor to regulate a period of time for which an electric power is fed to the motor by switching the electric power in accordance with the PNM signal. The switching frequency is arranged to vary depending on the variation of the load of the motor.

Abstract: In a speed feedback control system wherein a speed command signal and a speed feedback signal are compared and wherein the deviation between these signals is entered into a speed control unit, the speed signal is differentiated to apply speed damping in order to suppress the oscillations of the control system. In this case, while the speed command and the actual speed make a great difference transiently, the speed command is approximate to the sum between the speed feedback signal and the damping signal even transiently. Therefore, the speed command signal is compared with the sum between the speed feedback signal and the damping signal, and the fault of the speed control system is detected upon the fact that the deviation has exceeded a predetermined value.

Abstract: In an electric car, wherein the powering drive and the braking drive are executed by on-off controlling a current through a d. c. motor by means of a chopper, when the electric car is below a predetermined speed, a field coil of the d. c. motor is put into a series winding connection so as to carry out full field control, and when the car is above the predetermined speed, the field coil of the d. c. motor is changed-over to a shunt winding connection so as to carry out weak field control.The duty cycle of the chopper is controlled with the running state of the electric car taken into consideration in order that the field current at the time when the series winding connection has been changed-over to the shunt winding connection may become substantially equal to a value before the change-over, whereby the transient change of the current between before and after the change-over of the field coil is suppressed.

Abstract: Apparatus for preventing damage to resistor grids in the propulsion controller circuit of a direct current motor, particularly of the type used in driving railway vehicles, in which a line breaker relay is de-energized whenever the propulsion controller fails to progress from the switch position to the full series position within 15-25 seconds. The line breaker relay remains de-energized for the duration of the power cycle of the propulsion controller and becomes operational automatically after the master control handle is returned to the off position.

Abstract: A speed control system for a motor comprising a main motor circuit supplying motor current to the motor from an A.C. power source through a semiconductor element provided with a control electrode, trigger voltage supplying means supplying trigger voltage to the control electrode of the semiconductor element, motor voltage detecting means for detecting voltage induced in the motor, and automatically variable resistance means having its resistance value varied automatically depending on the detected motor voltage. In the system, the trigger voltage supplied by the trigger voltage supplying means is controlled depending on the variation in the resistance value of the automatically variable resistance means, and the firing angle of the semiconductor element is retarded in response to an increase in the detected motor voltage and advanced in response to a decrease in the detected motor voltage.

Abstract: Disclosed is an apparatus for controlling an electric motor for driving a cooling fan of an internal combustion engine. The apparatus comprises an engine operation detecting means, a timer, an engine temperature detecting means, a logical product generating means, and a motor controlling means. The electric motor is driven only when all of the following three conditions are satisfied: the engine is not operating; a predetermined timing period initiated when the engine stops operating has not expired; and a temperature in the engine room is higher than a predetermined value.

Abstract: A control circuit controls AC energization of a universal, series wound AC motor in a circuit breaker motor operator to power a breaker charging cycle. At the end of a charging cycle, the motor field winding remains energized from the AC source, however a braking resistor is switched across the de-energized motor armature to achieve dynamic braking. A timing circuit operates in the dual capacity of controlling dynamic motor braking and preventing continued running of the motor operator should the breaker operating mechanism fail to reset during a charging cycle.

Abstract: Wind driven rotors are affixed along the length of a flexible power shaft, and the shaft is suspended at a great height above the earth by means of a swivel. The lowermost end of the shaft is connected to rotate a ground supported energy conversion device. The winds aloft impart rotational motion into the wind rotors, whereupon the rotational energy of the shaft is converted into electrical power or other form of power by the conversion device. The swivel allows the rotating shaft to be affixed to a nonrotating suspension device. The suspension device is ground supported and includes a member having opposed ends anchored to the top of two towers or two spaced apart mountains, with the generator being placed therebetween.

Abstract: A servo controlled strip or tape linear indicating device is described in which a substantially nonresilient and nonself-supporting strip or tape is connected to servo motor means by a single attachment member at a fixed position along the length of the strip or tape. The strip or tape is freely slidable in a guide channel along its entire length and in all positions. The tape is visible with respect to a pointer through at least one transparent portion in the guide channel. The edges of the strip define with the guide channel play sufficient to prevent bunching or buckling of the strip. The servo motor means comprises D'Arsonval type motor having movable coil displaceable in an air gap of a magnetic circuit with fixed pole pieces.