Abstract: A method and system for altering the phase difference between a local motor and a remote motor wherein the phase difference is determined in terms of a count made of reference pulses at a first frequency when both motors are operating at a predetermined speed that is directly related to the first frequency. A phase altering count is determined from the phase difference count indicative of the degree to which the phase difference is to be altered and the reference pulses are produced at the local motor at a second frequency to alter the speed of the local motor. The phase altering count and the reference pulses at the second frequency are used to establish a time interval for operation of the stepping motor sufficient to make the desired change in the phase difference.

Abstract: A control system for regulating the torque and speed of an alternating current induction motor used in the traverse drive of an overhead travelling crane comprises an SCR bank controlled by a firing circuit responsive to actuation of an operator-controlled induction master control. The control system further comprises means for deriving a torque signal indicative of instantaneous rotor torque, means for deriving a speed signal indicative of instantaneous rotor speed, and summing means for combining the torque signal, the speed signal, and a reference signal from the induction master control to provide an error signal which is used to operate the firing circuit to thereby control the power delivered by the SCR bank to the motor and ensure that motor torque is constant for the control position selected or speed is controlled up to the torque level selected.

Abstract: A control system for regulating the torque and speed of an alternating current wound rotor motor used in the traverse drive of an overhead travelling crane comprises an SCR bank controlled by a firing circuit responsive to actuation of an operator-controlled induction master control. The control system further comprises means for deriving a torque signal indicative of instantaneous rotor torque, means for deriving a speed signal indicative of instantaneous rotor speed, and summing means for combining the torque signal, the speed signal, and a reference signal from the induction master control to provide an error signal which is used to operate the firing circuit to thereby control the power delivered by the SCR bank to the motor and insure that motor torque is constant for the speed selected. The means for deriving the speed signal measures the instantaneous frequency of the instantaneous current flow in the rotor (secondary).

Abstract: A synthesizer for multiphase waveforms is disclosed which is useful, for example, in open and closed loop control of a two-phase induction motor, such as for a magnetic recording disk spindle, utilizing a plurality of bistable elements, two for each phase, to control output power drivers. A single clock pulse counter is employed to time the setting and resetting of each bistable element according to some predetermined pattern controlled by combinational logic which presets the counter to proper values at appropriate times in response to external stimuli, such as speed feedback control and start-stop control.

Abstract: A destructive device for automobile radio equipment in which the radio equipment and an over-load power source connected in circuit to the radio equipment are enclosed in an open-front box closable by a removable face plate normally locked over the box by a key-operated lock, the circuit having two switches in series, one of them being actuated to a closed position when the face plate is removed and the other being normally closed when the lock is closed and opened when the lock is opened so that the circuit is closed to destroy the radio equipment when an attempt is made to remove the face plate without first operating the lock to an open position.

Abstract: A control system for regulating the torque and speed of an alternating current wound rotor motor used in the traverse drive of an overhead traveling crane comprises an SCR bank controlled by a firing circuit responsive to actuation of an operator-controlled induction master control. The control system further comprises means for deriving a torque signal indicative of instantaneous rotor torque, means for deriving a speed signal indicative of instantaneous rotor speed, and summing means for combining the torque signal, the speed signal, and a reference signal from the induction master control to provide an error signal which is used to operate the firing circuit to thereby control the power delivered by the SCR bank to the motor and insure that motor speed is constant.

Abstract: A super-synchronous Scherbius apparatus which enables wound rotor type induction motors to have a smooth speed control below and above the synchronous speed by controlling the secondary power in either the forward or backward direction through the connection of a cyclo-converter on its secondary side includes a first detecting circuit for detecting a signal corresponding to the primary voltage or the rotating magnetic field, a second detecting circuit for detecting a signal corresponding to the position of the rotor, and a calculating circuit for forming a signal corresponding to the phase of the secondary voltage in accordance with the signals of the first and second detecting circuits.

Abstract: A switch device in which two switch mechanisms are connected in series in an electric circuit which connects between a member to be operated and a power source. One of said switch mechanisms includes a stationary contact, a movable member having a movable contact mounted thereon for engaging and disengaging from said stationary contact and a permanent magnet attracted to or a spring applied against said movable member, said movable member being releasably connected to a slidable member connected to a vehicle accelerator pedal for movement with the slidable member in a portion of the movement of the slidable member. The other switch mechanism includes a stationary contact and a movable contact for making engagement with said stationary contact of the other switch mechanism and disengaging from the stationary contact by the slidable member.

Abstract: An axial-air-gap type semiconductor motor has a disc-shaped rotor, a pair of disc-shaped armatures coaxially located adjacent the opposite faces of the rotor with air-gaps therebetween, a system for detecting the rotational position of the rotor for generating an output proportional to the rotating speed of the rotor, and a semiconductor circuit operable in response to the output from the position-detecting system for controlling the armature current to effect constant-speed control of the rotation of the rotor. The rotor includes a field magnet. Two groups of armature coils are mounted on the face of each of the armature discs facing the rotor. The position-detecting system includes a control band which includes a plurality of control sections and which is synchronously rotatable with the rotor, and detectors which are located at fixed positions along the control band for generating an output in response to the control sections of the control band.

Abstract: A starting control apparatus for an AC load includes a bidirectional triode thyristor switching device connected in series between an AC power source and the load, a rectifying circuit connected in parallel to the bidirectional triode thyristor switching device, a first time constant circuit connected between output terminals of the rectifying circuit which discharges to turn on the bidirectional triode thyristor switching device when the charged potential reaches a predetermined potential, a second time constant circuit connected between the output terminals of the rectifying circuit and having a time constant larger than the time constant of the first time constant circuit and maintaining the charged potential in the ON state of the bidirectional triode thyristor switching device, and a speedy charging device which rapidly increases the charged potential to the sustaining potential of the second time constant circuit during the recharging period for the first time constant circuit while recovering the contr

Abstract: A latch mechanism for an apparatus having a rotatable member, a cabinet enclosing the rotatable member and an access door on the cabinet. The latch mechanism includes a first portion on the access door and a second portion on the cabinet which cooperate to lock the access door in the closed position at predetermined times in a cycle of operations. The second portion of the latch mechanism is controlled through a bimetal actuator which is heated by a low voltage current inductively generated in an auxiliary winding associated with a pump motor.

Abstract: A timer wherein the timing means of said timer includes an improved patch cord control which consists of the electrical coupling of at least two patch cords and two terminal means to individual power switching means and the grouping of timing resistors into at least two groups each of which consist of timing resistors of equal value for preselecting a maximum number of time intervals utilizing a minimum number of resistors.

Abstract: Power control apparatus and method for controlling polyphase excitation of a polyphase load. A first sequence of timong pulses are generated to represent each zero level voltage crossing of every phase voltage from a polyphase voltage source. After each of the predetermined numbers of the timing pulses has been generated, an energizng pulse is generated having a width of a predetermined duration. A set of power switches is provided coupling the polyphase source to the load via a set of load lines. The power switches are all rendered conductive to selectively couple phase voltages from the polyphase source to the load by each energizing pulse. This causes excitation of the load via repeating sequences of intermittent power pulses, with each power pulse being comprised of a selected grouping of the phase voltages from the polyphase voltage source.

Abstract: A driving circuit for a brushless DC motor provided with an element for detecting the angular position of the rotor of the motor, characterized in that by the output of the differential amplifier for amplifying the output of the detecting element, a switching element is rendered on and off during a certain portion of the duration of the output of the detecting element and that the motor is rotated at a constant speed by applying a rotation control voltage to an element for energizing the stator winding of the motor during the non-conductive period.

Abstract: A brushless d.c. motor includes a plurality of Hall elements 1-3 for detecting the relative positions of the rotor and stator poles, a comparator circuit 103 responsive to a bipolar input control signal A for generating an output signal B proportional to the absolute magnitude of signal A and an output signal D as a function of the polarity of signal A, a timing signal generator 104 for generating output signals E timed in relation to the Hall element outputs F and having a phase sequence in response to signal D, and a reversible current supply circuit 105 for driving a set of Y-connected stator windings 101 with currents C having a magnitude proportional to signal B and a phase sequence in accordance with signal E.

Abstract: A load distributor for an electric power system having a plurality of loads, each of the loads having a priority level, the load distributor including a first disabling means operable by a first load having a first priority level for disabling at least one other load having a lower priority level. The load distributor may further include second disabling means operable by a second load having a second priority level for disabling another load having a lower priority level, the second load and other load being some of the aforementioned plurality of loads. A thermostat or other variable device may be included in one or more of the loads for selectively varying the priority level of the load.

Abstract: A controlled current motor drive system and method for its operation utilizes an open loop technique and simple control circuit additions to modulate the inverter input current at six times motor frequency and reduce sixth harmonic torque pulsations. Conventionally generated current source inverter control signals at six times motor frequency are also used to derive a sixth harmonic ac signal which is fed to the controlled rectifier gating circuit as an additional input.

Abstract: A bellcrank lever has a locking cut-out with an oblique edge towards the end of one leg and a second leg which engages a notch in a switch. A blocking lever has a blocking lug at its free end which engages the locking cut-out. Insertion of the key swivels the blocking lever clockwise and swivels the bellcrank lever counter-clockwise out of engagement with the switch notch. Withdrawing of the key causes the levers to swivel in the opposite directions. The blocking lug then engages an extension in the locking cut-out and blocks the counter-clockwise swivel of the bellcrank.If the leg of the bellcrank lever cannot re-engage the switch notch, the oblique edge of the cut-out blocks the clockwise swivel of the blocking lever and the key connot be withdrawn.

Abstract: The invention relates to a brushless self-starting D.C. motor assembly of the type having a rotor with a permanent magnet providing a rotor field, a stator, and one or more stator windings. A D.C. source is provided along with electrically controllable power transistor switch means between said source and each of the windings. A position sensing coil element is mounted adjacent the rotor and has a core which is saturatable by the rotor field at a predetermined position of the rotor to provide a control signal. A control unit is disposed between the means and each of the switches for receiving the control signal and actuating each of the switches in turn in response thereto. The core is preferably ferrite and preferably a permanent magnet.

Abstract: A battery backup system for an AC energized DC supply has an AC line monitor for producing a pulse signal having a pulse width dependent on rise time of the AC signal and a frequency dependent on zero line crossings of the AC signal. The pulse signals are checked for frequency and pulse width by being used to control the charging time of a timing capacitor for a timer and to be compared with the pulse width of a predetermined reference pulse, respectively. The occurrence of a defect in the pulse signals stemming from either pulse testing criteria is effective to trigger an SCR circuit into conduction to connect a backup battery to the load devices to replace the DC power formerly being supplied by the AC line. After restoration of the AC power, the backup battery is removed following a fixed time delay to allow the AC powered DC supply to stabilize.