Abstract: A relay coil associated with a pair of contacts connects an electrical source to a load. Actuation of a coil sensing element by a trigger input signal supplies current to the coil. In response to the trigger input signal the load sensing element supplies a latch maintain signal to a switching element which becomes conductive to establish current flow to the load. As long as the load sensing element detects current to the load the switching element remains conductive for a "latched" state. Interruption of current to the load converts the elements to an "off" state until another trigger input signal is transmitted to the load sensing element.

Abstract: A device comprising an inductor connected to current supply means; a condenser designed for parallel connection to an inductive load; and switch means having a short response time and controlled so as to interconnect the aforementioned supply means, inductor and condenser according to a number of sequentially prearranged circuit configurations.

Abstract: In the magnetic chuck control disclosed herein, the chuck winding is selectively energized in one direction or the other through respective triggerable semiconductor current switching devices. Successively reducing current levels are applied in successive phases of operation, the polarity of the current being reversed in successive phases. During a first portion of each phase the device is triggered to apply a corresponding preselectable voltage. During a second portion of each phase the switching devices are triggered quite late to provide an average voltage which opposes the current flow which was induced during the first portion thereby to quickly reduce the level of current flowing in the winding.

Abstract: Electric control apparatus (20) for equipment (1) comprising a driving circuit (5) for generating a signal (S.sub.1) to drive the equipment as installed in a vehicle, the driving circuit including circuitry having a first specified working voltage range, and a breaking circuit (6) operatively interposed between the driving circuit and the equipment, the breaking circuit including a first switching circuit (100) for operatively interrupting the supply of the drive signal to the equipment under a condition that the supply voltage (Vdd) is lowered below a first predetermined level (V.sub.

Abstract: A device is provided that begins an electrical starting mode in a parallel circuit configuration providing an improved speed of response and after an interval of time, current is switched to a series circuit configuration for operation during a run mode. The device is initially energized at several times the power normally required to activate a coil and switching means is thereafter utilized to reduce power to a normal requirement soon after the coil is energized. Specific hardware is provided in the form of schematic diagrams for defining the operation of the invention.

Abstract: A circuit and method for actuation of a gas intake or exhaust valve which is electromagnetically held in its opened and closed positions by an actuator assembly having a ferromagnetic element attractable by actuating solenoids. Control of the holding current flow through the solenoid coil is provided by a relaxation circuit element, and the excitation current is directly monitored and measured. Upon deexcitation of the coil and relaxation circuit-element activation, the decay current is not measured but is instead simulated. The relaxation circuit is supplied with pulsed current during the stationary phase of the valve, the current being measured in the pulse cycle during current supply, and is turned off upon exceeding a ceiling value. After the decay current has reached a threshold value, the current is turned on and permitted to rise momentarily. It is thereafter cycled off and on between an I.sub.1 and I.sub.2 value which is only about 10-20% of I.sub.max, the capture current.

Abstract: A solenoid drive circuit in which a solenoid is intermittently driven while in a powered state. A diode and a resistor are connected from ground to opposite ends of the solenoid to quickly discharge the solenoid. However, during intermittent driving the resistor is short circuited.

Abstract: A heated bedcover containing an electrical heating element therein is provided with an integrated solid state control circuit which functions providing control over the heating element both for comfort control so as to maintain a desired heat output from the heating element and to also provide protection against overheating conditions in the blanket.

Abstract: A zero-current a.c. switching system is provided for controlling actuation of relay contacts between a power supply and a load. A primary switch selectively energizes the relay to maintain the relay contacts in the closed state. The load current flowing through the relay contacts to the load is sensed. A secondary switch responds to the sensed load current for normally conducting to energize the relay in parallel with the primary switch. The secondary switch ceases conducting each time the load current drops below a predetermined level to cease energizing the relay and open the relay contacts the next time the load current drops below the predetermined level following the opening of the primary switch.

Abstract: This safety monitoring system for punch press operators is designed to prevent the operators from being injured by such presses or other factory equipment. Primarily, it consists of a pair of wrist units which are strapped to the wrists of the operators, and which include optical fiber cables and a latching assembly, and the optical fiber cables are used in cooperation with a pair of identical electronic circuits employing LED's, a light sensitive transistor, a pair of other transistors, a zener diode, and a relay, for instantly shutting a punch press on or off.

Abstract: The control circuit according to the invention consists firstly of two control terminals (S.sub.1, S.sub.2) to which drive pulses of at least two different types can be applied, i.e. a first pulse type (S) designed to obtain one position (S) of the solenoid and which present a first level of amplitude, and a second pulse type (R) designed to obtain a second position (R) of the solenoid and which present a second level of amplitude different from that of the pulses (S) of the first type and with the same polarity and secondly, a discrimination circuit (R.sub.1, R.sub.2, A) for the pulses (R, S) of these two types according to their level of amplitude, this discrimination circuit (R.sub.1, R.sub.2, A) being connected to a switching circuit (CS, CS', CR, CR') controlling supply of the solenoid (B). The invention is also applicable to solenoids comprising one coil as well as to solenoids having two separate coils or with a common intermediate connecting point.

Abstract: A solenoid driving circuit for supplying an exciting current whose level suddenly increases at the beginning of the flow of the current has a voltage inducing circuit for providing a pulse-like current component which suddenly increases at the beginning of the flow of the exciting current, a unidirectional element for supplying the pulse-like current component to the solenoid, a voltage limiting element for limiting the level of the pulse-like current component and applying a d.c. power to the solenoid, and a circuit for providing a stand-by current and the holding current to the solenoid, whereby the solenoid is effectively supplied with sufficient energy for driving it at high speed and the power required for maintaining the operation of the solenoid is reduced.

Abstract: A solid state switching system for use with solenoid operated control valves, especially control valves for dangerous machinery including a light screen guard fitted for personnel protection. The switching system comprises two transistors in series with the solenoid coil. A self-checking monitoring system for monitoring the state of the two switches is provided. The monitoring system has a plurality of switching elements arranged in such a way that no single electrical fault can result in an inadvertent energization of the control valve. Specifically in the event that one of the switches is off while the other is still conducting, the monitoring system inhibits switching on of the switch that is off. The monitor system verifies that no fault has occurred during any one cycle of operation which might not otherwise be apparent. Every component in the switching and monitoring circuits functions during each on/off cycle.

Abstract: An electronic circuit for the performing of a monostable switching function in a bistable relay through the conversion of binary input signals into control signals for the bridge switching circuit consisting of two bridge branches with complementary operating electronic switches. The flow direction of the current is reversible in the relay through intermediary of the bridge switching circuit, and the relay is switchable at each change in the level of the input signal through a pulse with a predetermined energy content.

Abstract: An electrical drive circuit arrangement to control the energization of a reactive load with a high voltage including a control stage, an electrically isolating control signal transformer and an output stage including power control semiconductor devices and having an energization input for a high voltage electrical supply and an output for the connection of a reactive load, the high voltage being prevented from reaching the control stage via the input of the output stage by the isolating transformer, the control stage including a noise-resistant guard responsive to circuit condition signals to permit or prevent generation of the control signal, the transformer restricting the signal to the output stage to a permitted control signal and the output stage generating a protection signal on a current surge in a connected reactive load, the protection signal being a potential low enough for direct application to the control stage without the need for isolating transfer to protect against the high voltage reaching th

Abstract: The invention relates to an electronic device controlling the electromagnet of a multiple operation electrical apparatus.The electromagnetic coil (14) is connected in series to a triac (25) regulated by a generator (32) associated with a monostable flip-flop (34) designed to supply a single pulse of time-length T at each order from a logic circuit (36). A selector (38) cooperates with each output S.sub.1, S.sub.2, S.sub.3 . . . of the logic circuit (36) to choose a predetermined mode of operation of the apparatus (10), particularly remote-operated switch, contactor, or ON-OFF mode.

Abstract: A protective control system is provided for stopping an engine-driven pump when a fault condition such as low oil level, low oil pressure or high temperature occurs in the engine. The protective control system includes an electric battery, a solenoid valve regulating fuel (or air) flow to the engine and energizable from the battery, an electronic circuit energizable from the battery for controlling the solenoid valve, and fault-sensing switches for controlling the electronic circuit and shutting off the fuel supply to stop the engine upon occurrence of a fault. The electronic circuit includes a solid state voltage regulator device connected between the battery and the solenoid valve, and this device includes an adjustment terminal which is biased to control the power supply to the solenoid valve. The electronic circuit further includes a transistor which controls the bias on the adjustment terminal and the transistor, in turn, is responsive to operation of any one of the fault-responsive switches.

Abstract: A shutdown circuit for a TV projection monitor includes a standby power supply energizing a main power supply through contacts controlled by a relay winding in the load circuit of a control transistor that is cut off by a pair of latch transistors that receive operating power through the relay winding. Closure of a momentary contact switch effectively disables the latch transistors and grounds one end of the relay winding which is thereby energized to enable the main power supply. Disabling the latch transistors permits the control transistor to become conductive and hold the relay winding energized. A subsequent closure of the momentary contact switch applies sufficient potential to the latch transistors to drive them conductive and disables the relay winding for deenergizing the main power supply.

Abstract: An electrical control system including a source of electrical power and an electrical load coupled together by a power switch having alternate circuit open and circuit closed conditions. A closure means activates the power switch to a circuit closed condition to produce power transmission between the source and the load in response to a closure signal produced by a condition responsive control circuit. Connected in series with the power switch is a protective switch also activated from a circuit open to a circuit closed condition in response to the closure signal. A sensing circuit produces a fault signal in response to a closed condition of the power switch and a simultaneous circuit open condition of the protective switch.

Abstract: A one shot firing circuit for electrically powered tools is described which includes a manually operable normally open trigger switch connected electrically in series with a solenoid coil and an AC power source for controlling the supply of electrical power to both the firing circuit and the solenoid, such that when the trigger switch is open, the path of current flow to the solenoid coil is physically interrupted. The firing circuit also includes an SCR connected electrically in series with the trigger switch, the solenoid coil and the AC power source, for controlling the flow of current through the solenoid coil after the trigger switch has been closed.

Abstract: An improved vacuum pump driven by a unique electrically powered servo motor. The vacuum pump comprises an extremely simple and inexpensive pump arrangement utilizing a reciprocating piston and a rolling lobe diaphragm to eliminate the need for close tolerances while still providing high efficiency. The servo motor includes a pair of relatively movable sequentially operating armatures which eliminate the need for any external timing mechanism or for any complex delay mechanism. The servo motor of the present invention is inherently capable of operating the pump as a self-actuating demand pump.

Abstract: A current director and interface circuit to prevent damage to a transformer relay by the simultaneous activation of a plurality of bidirectional switches. A current director prevents current flow in the secondary winding of the transformer relay in a second direction above a predetermined switching threshold for a predetermined succeeding time period after current has flowed in the secondary winding of the transformer relay in a first direction above a predetermined inhibit threshold during a predetermined preceding time period.

Abstract: A circuit for controlling a plurality of inductive loads, includes a plurality of low voltage transistors controlled by a flip-flop so that only one of the low voltage transistors is on at any given time. These low voltage transistors connected one end of respective ones of the loads to one rail of a supply. Diodes connect the other ends of the loads to a common point which is connected to the other rail of the supply by a single high-voltage transistor. Further diodes connect said one end of the respective loads to said other rail to protect the low voltage transistors from high voltages caused by the interruption of current in the loads.

Abstract: A relay coil circuit with a switching regulator for coil current to maintain, after closing, a sufficient holding current by the inductance of the coil acting as a current source without supply current.

Abstract: A coded key operated solid state entry system for a controlled access to a multiplicity of electronic circuits by the use of corresponding coded keys embodying a detection and monitoring system, the detection and monitor system being activated by the insertion into the keyway of a coded key particularly adapted to successively engage a plurality of switches which engage a timer for a timed interval of key insertion and which energizes a circuit to unlatch normally latched tumblers and which upon rotation by the key to the extent of the code of the key, an optic coupling circuit is energized and the code of the tumblers is read, the optic coupler interfaces with a comparator which functions to match the code read with a corresponding coded electronic circuit. If the code is not matched with a corresponding circuit, the timed interval of the timer will expire and the circuit unlatching the tumblers will be caused to become de-energized locking up the tumblers and the key.

Abstract: Disclosed herein is an electronic timing circuit which can be incorporated in an accelerator pump timing control, also disclosed herein. The timing circuit is adapted to be connected to the first and second power terminals of a DC supply and for energizing a load, for example, a fuel pump solenoid valve, during a predetermined timed cycle. The circuit includes a thyristor having an anode-cathode path adapted to be connected to the load so that when the thyristor is rendered conductive by a trigger pulse applied to the gate, current flows from the DC supply through the thyristor to energize the load and start the timed cycle. A transistor control circuit including a transistor connected in series relation with the anode-cathode path is operable for controlling the energizing current flow through the thyristor, subject to a relaxation oscillator included in the timing circuit.

Abstract: A relay driver circuit is disclosed in which a relay coil is operated by enabling the collector-emitter path of a switching transistor. In order to avoid damage to the transistor from voltages induced in the relay coil when the relay is turned off, an isolating semiconductor device is inserted between the transistor and the relay coil. This semiconductor device is operated in synchronism with the driving transistor and thus isolates the driving transistor from transients during the de-energization of the relay.

Abstract: This invention is for controlling the energization of a furnace, air conditioner or the like that has two thermostats, one to control the upper temperature limit and the other to control the lower temperature limit. A manually settable programming means is provided that is operable on a continuous basis from the voltage across thyristor devices associated with the thermostats which control the on-off condition of the furnace. The programming device devides time into slots and has a switching means that enables a thyristor of a selected one of control paths to conduct when its respective thermostat is closed and to disenable the thyristor of the other control path from conducting in any predetermined time slot. Power for operating the programming device is obtained from the voltage across the thyristors when they are conducting and when they are non-conducting.

Abstract: The Automatic Memory and Environmental Security System is a solid state electronic device to be employed in a motor vehicle for the specific purpose of closing any and all electrically operated windows, and roof panel, and locking any and all electrically operated door locks, which may have been left open or unlocked purposely or inadvertently. The system is also designed to close any and all electrically operated windows and roof panel left open when the surrounding humidity reaches 100% (the appearance of rain, drizzle, etc.). The unit is designed so that there is no interference with the normal operation of the above-named electrical device(s) after being employed in the said vehicle.

Abstract: An electric switch arrangement for use as a current supply switching means for a bipolar electric load is disclosed, comprising two switches connected in series with each other and with the load and located on opposite sides of the load. A monitoring equipment is provided for supervising the operation and function of said switches. Said monitoring equipment comprises potential generating means which are arranged, when both said switches are open, to generate at each pole of the load a potential deviating from the potential existing at said pole when anyone of said switches is closed or both said switches are closed, and sensing means which are arranged to sense the potential of at least one of the poles of the load.

Abstract: A control system for use with a printer device or the like comprises means whereby the time during which a subject to be controlled, such as the thermal head of the printer, is driven may be determined in accordance with the quiescent period of the subject to be controlled.

Abstract: A remote control wiring system is provided which includes a transformer for providing power to a low voltage subsystem which, through relays, controls the opening and closing of higher voltage load circuits of the remote control wiring system. A plurality of relays are provided, one for controlling each of the load circuits. A first circuit includes in series a first solid state switching device, such as a suitable transistor, SCR or triac, and a relay, or a plurality of relays connected in parallel. Similarly, a second circuit includes in series a second solid state switching device, such as a suitable transistor, SCR or triac, and the relay, or the plurality of relays connected in parallel. A two-position switch is incorporated in the low voltage subsystem in association with the first and second circuits.