Abstract: A protective relay system detects a first electric variable and a second electric variable of a power system to discriminate in a time series whether or not a fault portion of a line or equipment included in the power system exists within a predetermined range, so as to determine whether protection of the power system should be carried out. The system includes a digital filter for outputting a first difference electric variable data indicative of a difference between at least two sample data of plural sampling data of the first electric variable and a difference between at least two sample data of plural sample data of the second electric variable at plural sampling times of the time series. The system also includes an addition filter for outputting first and second additive electric variable data indicative of orthogonal vector data with respect to the first and second difference electric variable data.

Abstract: When a trouble occurs in a cable, a feeding pass for another cable is ensured. In a feeding pass switching circuit, optical fibers are respectively connected to the terminals A, B and C. When a negative current is applied to the system in a state where a BRANCH2 is put in an open circuit and a TRUNK is grounded, a relay K1 is activated, and then a relay K2 is activated. Successively, when a positive current is supplied from the TRUNK, a cable connected to the TRUNK and a BRANCH1 is fed from both terminals. When the positive current is supplied from the BRANCH1 in a state where the TRUNK is put in a open circuit and the BRANCH2 is grounded, a relay K3 is activated. Successively, when the negative current is supplied to the BRANCH2, a relay K5 is activated. In such a manner, the power is fed to each feeding pass from one terminal.

Abstract: A method is provided for adapting a control for an electromagnetic actuator for actuating an adjusting device in a system, in particular for actuating a cylinder valve in a piston engine, to operation-dictated changes in the electromagnetic actuator. The electromagnetic actuator includes at least one electromagnet, a restoring spring, an armature operately coupled to the cylinder valve and disposed for movement counter to the restoring spring. The electromagnet is energized, during an idling phase of the engine, with a current having a path deviating from a normal current in a normal mode of operation. Portions of a course over time of current through the electromagnet are detected. The detected course of current is compared with a predetermined curve. The control for the electromagnet for the normal mode is adapted if there are deviations between the detected course of the current and the predetermined curve.

Abstract: An electronic relay having a current sensor device (C1, C2, C3), logic inputs (3) and an electronic circuit (4) provided with processing means capable of calculating, from the current signal (I) supplied by the current sensor device and a rectified voltage signal (V) supplied by one of the logic inputs, the value of the power factor of the motor (cos.phi.) and/or the value of the power supply voltage (U) of the motor.

Abstract: An electromagnetic switch for opening and closing a set of contacts has a microprocessor which monitors coil current to determine the state of the contacts. The switch relies on the phenomenon that the inductance of the switch coil changes significantly between the open position of the contacts when the switch armature carrying the moveable contact is spaced by an air gap from the core of the electromagnet, and the closed position in which the armature abuts the core. For an AC energized coil, which is self-limiting in that the increase in inductance from closing of the contacts reduces the current to the holding value automatically, a coil current of less than about one/half of the nominal open contact value is an indication that the contacts are closed.

Abstract: An electrical circuit applies an oscillatory electrical current to a coil of a solenoid in order to cause the solenoid to move in response to a command signal. The circuit includes a signal divider for generating an upper peak current signal value from the command signal and a lower peak current signal value which is a fixed percentage of the upper peak current signal value. A current sense resistor generates a current sense voltage representing current through the coil. A first comparator compares the current sense voltage to the upper current signal value. A second comparator compares the current sense voltage to the lower current signal value. A set/reset flip-flop latches a current driver on and off. A current driver applies a driving current to the solenoid coil as a function of output signals generated by the first and second comparators so that the coil current will have a lower peak current value which is substantially a fixed percentage of the upper peak current value.

Abstract: An electromagnetic contactor to which voltage generated through full wave rectification of an alternating current or DC voltage is loaded. The device provides control for a closing operation with a large pulse width according to a set-up frequency and control for maintaining the closed state of the electromagnetic contactor with a small pulse width for executing ON/OFF control. The device comprises a detector for detecting a peak voltage value of the voltage subjected to full wave rectification and an average value or an effective value thereof and a controller for stabilizing the input at a constant level by controlling a pulse width of a frequency set up based on a voltage value detected by the detector.

Abstract: Overcurrent protection arrangements including a relay comprising two coils wound on a common magnetic core and a PTC device coupled in parallel with the relay contacts. The arrangement comprises a circuit interruption element which has a normal state which permits the flow of a normal circuit current, I.sub.NORMAL, to pass through the system, and a fault state which permits the flow of at most a reduced current, I.sub.REDUCED, substantially less than I.sub.NORMAL. A first control element is coupled in series between the power supply and the load, and is functionally linked to the circuit interruption element so that when the current through the first control element increases from I.sub.NORMAL to a relatively high current, I.sub.FAULT, the first control element can convert the circuit interruption element into the fault state.

Abstract: A solenoid device, for example in an electrical contactor system, is provided for use with an alternating current power source. An electrical contactor includes an electromagnetic coil assembly configured to generate a non-zero effective magnetic force in response to an alternating current signal applied across the coil assembly. A switch proximate the coil assembly is configured to operate responsively to the effective magnetic force. A wave shaping device is configured to introduce a direct current component to an alternating current signal provided by the alternating current power source and to output at least part of the alternating current signal modified by the direct current component across the coil assembly.

Abstract: A device for driving a load, in particular an electromagnetic load. The device includes a current detector for detecting the current flowing through the load, a power transistor connected in series to the load, which is triggered in dependence upon the current flowing through the load, and a further transistor arranged in parallel to the power transistor. The device has the advantage of reducing the power dissipation in the power transistor.

Abstract: A solenoid driver circuit is controlled by an electronic control module ("ECM") and eliminates many components required for a high voltage power supply required by the prior art. The solenoid driver circuit includes a high voltage select switch, a select switch and a modulation switch that are controlled by the ECM. The ECM causes the switches to be opened and closed so that the back EMF created by the solenoid coil when the modulation switch is opened can be recaptured by charging a capacitor. That energy can then be used to energize the solenoid coil.

Abstract: A proportional solenoid valve control system limits the current flowing in a solenoid valve if the command current is higher than a fixed value which can be set by a user. A current command limiting circuit limits the current command by providing a fixed value as an output when a current command exceeds the predetermined level.

Abstract: A method of recognizing armature impingement in an electromagnetic actuator having an electromagnet including a solenoid, an armature movable toward and away from the electromagnet and return means for exerting a force on the armature. The method includes the steps of maintaining a solenoid current at a predetermined magnitude I.sub.max during a predetermined period T.sub.A for capturing the armature at the electromagnet; switching off the solenoid current at a moment t.sub.1 upon lapse of the period T.sub.A ; upon lapse of a period T.sub.1 running from moment t.sub.1, oscillating the solenoid current between a lower holding current threshold I.sub.H1 and an upper holding current threshold I.sub.H2 ; detecting a current course from moment t.sub.1 ; and deriving a signal from such current course.

Abstract: An internal combustion engine assembly including a solenoid pump having an armature and a solenoid winding encircling the armature such that the armature moves in response to current flow, including unwanted current variations, through the solenoid winding and a control circuit connected to the solenoid winding for detecting unwanted variable current flow in the solenoid winding and for controlling actual current flow in the solenoid winding in response to the detected unwanted variable current flow to thereby precisely control movement of the armature.

Abstract: Even when a plurality of dispersed power generation systems are connected to a utility gride, an islanding-operation prevention apparatus can easily and assuredly prevent an islanding operation of each dispersed power supply constituting the corresponding dispersed power generation system. The apparatus includes a breaker provided between the utility gride and a dispersed power supply, an electric-power-value detector for detecting a value of electric power from a power line connected to the utility gride, a switch for electrically connecting or disconnecting an electric-power changing device for changing the value of electric power to the power line in accordance with an output from a pulse circuit, and a controller for controlling the breaker in accordance with the width of fluctuations of the value of electric power during the connection or the disconnection. A dispersed power generation apparatus and a dispersed power generation system uses such an apparatus.

Abstract: Electronic driving components sized to drive contactors of a determined power class are generally used. The object of the invention is to create a process and circuitry which allows contactors of different power classes to be driven by a single driving component. The user selects on a scale the switching position corresponding to the contactor to be driven. A reference voltage proportional to the magnitude of the starting current of the respective contactor is thus selected. An automatic regulation keeps constant the starting current during the starting time of the contactor. For that purpose, a measurement voltage proportional to the magnitude of the starting system and dropping across a measuring resistor is supplied to a first input of a comparator, a reference voltage which may be selected by a coding switch (6) being applied to the second input of the comparator. The output of the comparator co-operates with a switching element which switches the starting current.

Abstract: A varying voltage is applied across a coil of a contactor. The varying voltage has a characteristic (frequency) which varies as a function of the position of the armature. The varying voltage is transmitted to a coupler which transmits information to a controller. The coupler may include one or more light sources (LEDs) which are sequentially energized and de-energized to sequentially render a phototransistor conducting and nonconducting. The frequency of the output from the coupler corresponds to the frequency at which the phototransistor is changed between the conducting and nonconducting conditions. A controller determines whether the frequency of the output from the coupler corresponds to the intended position of the armature of the contactor or to an unintended position by comparing the frequency of the output from the coupler to known frequencies for various positions of the armature.

Abstract: An internal combustion engine assembly including an internal combustion engine, an electronic control unit for generating control signals for controlling the engine and a solenoid oil pump for supplying oil to the engine. The oil pump includes an armature and a solenoid winding encircling the armature and being connected to the electronic control unit so that the electronic control unit causes movement of the armature and so as to allow the electronic control unit to detect the flow of current in the solenoid winding.

Abstract: An electronic device, for example an irrigation controller, accumulates energy from a source of energy, for example from incident light, in order to progress, over time, from an inoperative un-powered to an operative powered condition in a positively controlled, graceful and orderly manner. The device so progresses to operability regardless that it should, from time to time and at times, be totally devoid of energy, and regardless that it may accrue energy only but exceedingly slowly over periods of days, weeks and longer. A power monitor circuit of the device is made from an electrical circuit technology that is reliably operative at a relatively low voltage level, typically from BICMOS technology, whereas other device electrical circuits are operative only at a relatively higher voltage level, and are typically made from CMOS technology.

Abstract: A control relay circuit and method for controlling a relay having a coil, for use, in particular, in operation of a light fixture circuit having an HID lamp. The relay control circuit has an input for receiving a control voltage signal and a voltage storage element connected across the input. The voltage storage element develops a voltage level as a function of time in response to the control voltage signal. A thyristor circuit, a switching element and the coil of the relay form a series circuit that is connected in parallel to voltage storage element A switch controller is connected in parallel to the voltage storage element and is also connected to the switching element.

Abstract: The first zero crossing of the power signal, after the detection of an opening/closing signal, initiates a series of predetermined, timed, steps which reduces or eliminates the overvoltage after opening/closing a circuit breaker on a high power line.

Abstract: Electronic drive circuitry for a solenoid that utilizes a pulse width modulation scheme is disclosed. The solenoid is connected in series with a transistor and a sense resistor. The voltage across the sense resistor is compared to a reference value to determine if an over-current condition exists within the solenoid. The circuitry operates on a repetitive time window scheme in which current is allowed to flow through the solenoid at the beginning of each time window, regardless of whether an over-current condition exists. If an over-current condition was detected at any time during the time window, then the current will be shut off to the solenoid during the next time window after the initial portion of that window. Conversely, if no over-current condition was detected during a time window, current will be allowed to flow during the entire duration of the next time window.

Abstract: A device for preventing welding of the switch contacts of a heavy duty electromechanical relay comprises means (15, 16 and 17) adapted in use for monitoring the voltage supply to the relay coil (2) and detecting low voltage excursions therein. A counter (14) counts the number of low voltage excursions in the voltage supply to the relay coil (2) and an electronic switch (12) disconnects the voltage supply to the relay (2) if the number of low voltage excursions counted exceeds a predetermined number.

Abstract: An electromagnetic lock employs a pre-wound bobbin which is forced onto the E-shaped lamination stack of a magnetic core. The housing is configured in two longitudinal sections which are relatively pivotal to provide access for circuitry within the housing for both an outswinging and an inswinging door lock installation. The electromagnet also employs a circuit to sense the power supply to the electromagnet and to automatically select the operating voltage of the electrical coil.

Abstract: An electric-supply-switch relay-circuit includes a first switch unit for passing an input current from an electric-supply line as a relay operating current; a relay for performing switching operations in accordance with the relay operating current; and a current detect control unit for detecting the input current. When the input current is found to be equal to or larger than a predetermined value necessary for operating the relay, the current detect control unit turns on the first switch unit to thereby allow the input current to the relay.

Abstract: The invention relates to a load drive circuit which is able to detect an "on" fault of a switch element for controlling power to a load, and reliably interrupt the load current. A monitoring sensor is provided which generates an output when energy is supplied to the switch element of the switch circuit from outside the circuit, and a received signal level of the energy is a high level with the switch element "off", but does not generate an output when a received signal level of the energy is a low level with the switch element "on". Through logical processing of the output of the monitoring sensor and a load drive signal for driving the switch element, using a logical sum operating circuit and a self-hold circuit, the relay contact points can be prevented, at the time of an "on" fault of the switch element, from following the load drive signal, and from "hunting".

Abstract: A safety switching arrangement for the switching on and off of the power supply (11) of two actors (12a, 12b) for example relays, which, in dependence on the switching on of the current, and in dependence on a sensor switching signal (13a, 13b) jointly set a working apparatus (22) in operation, the safety switching arrangement comprising two main switches (14a, 14b) arranged between the power supply (11) and each preferably earthed actor (12a, 12b).

Abstract: An electronic device offering protection against connection of a direct current power supply unit with reverse polarity includes a branch disposed between two potential lines and including a reverse biased diode and a first component sensitive to a flow of current. A first switch is disposed on the downstream side of this branch, on one of the potential lines. A control circuit has two terminals receiving a control signal and, connected in series between those terminals, a second switch and a second component sensitive to a flow of current. The first switch, normally open, is closed by the second sensitive element if the latter detects a flow of current. The second switch, normally closed, is opened by the first sensitive component if the latter detects a flow of current.

Abstract: A circuit breaker device for use on an electric vehicle has a high-voltage drive power supply for supplying electric energy to a load to drive the electric vehicle, a circuit breaker for cutting off the electric energy supplied from the drive power supply to the load, a sensor assembly for detecting conditions of the electric vehicle, and a controller for controlling operation of the circuit breaker in response to a detected signal from the sensor assembly. The controller is connected to a low-voltage accessory power supply for energizing accessories on the electric vehicle, and also connected to the drive power supply through a power supply converter for converting the electric energy supplied from the drive power supply, so that the controller can be energized at all times by at least one of either the accessory power supply or the drive power supply.

Abstract: An apparatus for the electromagnetic control of the suspension of an object including an electromagnet including an inductive coil, a source of electric power for the electromagnet which source includes a controllable electric supply device capable of delivering a controlled electric supply to the coil of the electromagnet, a control signal producer for producing an error control signal in response to an incremental change in a parameter related to the position of the object relative to the electromagnet and a negative feedback control loop for feeding an error control signal generated by the control signal producer to the electrical supply device to adjust the electrical supply to the coil so as to stabilise the suspension of the object relative to the electromagnet, wherein the control signal producer includes a detector for detecting the component V.sub.

Abstract: An electrically operated control device and system for an appliance and method of operating the same are provided, the system comprising a power source of alternating electrical current that has a repeating voltage wave cycle and a repeating current wave cycle, a load for using the electrical current to provide an output of the load for the appliance, a relay having normally open contacts and a coil for closing the contacts only when the coil is energized, an electrical circuit for interconnecting the power source to the load through the contacts only when the contacts are closed, and a control unit for causing the coil to close the contacts substantially at a certain point on the voltage wave cycle each time the relay coil closes the contacts from the open condition thereof whereby the current flow through the contacts at each closing thereof is at substantially a desired level thereof.

Abstract: An electromagnetic switch device which features a mobile assembly having contacts cooperating with fixed contacts and displaced by a solenoid. The switch also features an analog sensor for measuring the position of the mobile assembly and electronics for processing the output signal of the position sensor to control the coil current.

Abstract: Apparatus and method for controlling current flow through a magnetic coil actuator of a solenoid valve. The current through the magnetic coil is measured by sensing the voltage drop across a precision resistor in series with the coil. The apparatus includes a power switch for alternately switching the coil on and off. A flyback diode is coupled in parallel with the coil for operation during coil shut-off. A first voltage sensor continuously measures the combined voltage drop across the coil and the power switch. A second sensor, coupled across the precision resistor, samples the current flowing through the coil. The samplings occur synchronously with coil turn-on, and are delayed by a predetermined time delay which is long enough to allow the current flowing through the coil to reach steady state before the current is sampled. Circuitry is provided for employing the sensed voltage signal and current samplings to produce a signal whose value is a function of the resistive component of coil impedance.

Abstract: The system for timing the opening and closing of a high power switching arrangement breaker used in an electrical transmission system measures the temperature of the breaker and the phase of the power signal being switched. A control circuit provides a control signal for opening and closing the breaker in response to an initiating signal, the control signal being timed as a function of the temperature and the phase angle to make sure that contact is either made or broken at an appropriate time to reduce arcing. By taking into consideration temperature and its effects on the response of the breaker, arcing is significantly reduced.

Abstract: An electronic switching arrangement for controlling a coil includes a capacitor for energizing the coil by momentarily passing a current therethrough so as to generate a required attractive force for movement of the armature. After movement of the armature, only a lower holding current is supplied. Arranged parallel to the coil is a voltage divider which cooperates with a transistor to detect and evaluate an unintentional movement of the armature.

Abstract: A solid state relay having circuitry incorporated therein which senses line conditions and load conditions and activates an alarm when a fault is detected.

Abstract: In a system for triggering an inductive consumer, particularly a consumer for controlling an internal combustion engine, the consumer is coupled via a circuit element to a voltage source. A control means triggers the circuit element in the switching mode for a preselected ON duration. Furthermore, means are provided for measuring the current flowing through the inductive consumer. To measure an actual current value, a first current value is measured shortly after the closing operation, and a second current value is measured immediately before the opening operation.

Abstract: A trip control device for monitoring and tripping a circuit breaker includes a first voltage detector 11 and a second voltage detector 12 for detecting the first and second reference voltages corresponding to the maximum allowable voltage level and the operation resumable voltage level, wherein the second reference voltage is set higher than the first reference voltage. The output of the second voltage detector 12 at logical 1 reduces the output of the first voltage detector 11 to the logical 0 through a transistor 14 and a capacitor 15 with a predetermined delay. The logical sum T of the outputs of the first voltage detector 11and the second voltage detector 12, output from the OR gate 13, turns off the drive circuit 3 when at logical 0, to de-energize the electromagnetic coil 4 and render the associated circuit breaker incapable of being made.

Abstract: A control circuit synchronizes operation of a latching relay to extend contact life. The relay is switched using an H-bridge drive circuit. The synchronization is done using a two-step delay. The first delay is provided by a phase shifter, which delays the timing signals used by a logic controller relative to a zero crossing. The second delay is provided by an adjustable timer circuit including a potentiometer. The two delays are used so that the latching relay is tripped at a selectable time coinciding with the second zero crossing after a switching command is received.

Abstract: A solenoid driver applies an actuation current to a solenoid for a predetermined period and a lower holding current thereafter. A switching device pulses the applied current within upper and lower limits to maintain the actuation and holding current amplitudes, the pulses being integrated by solenoid inductance into a substantially steady-state current. A multiprocessing unit determines the amplitudes of solenoid current. A signal representative of desired current amplitudes is compared with a signal representative of measured solenoid current, and a signal representative of the difference therebetween is used to control the switching device. Voltage developed across a resistor in series with the solenoid is input to a differential amplifier having connected to its output a peak detector that mimics the decay rate of current in the solenoid, the signal representative of measured solenoid current being obtained from the peak detector.

Abstract: An electrically operated control device and system for an appliance and method of operating the same are provided, the system comprising a power source of alternating electrical current that has a repeating voltage wave cycle and a repeating current wave cycle, a load for using the electrical current to provide an output of the load for the appliance, a relay having normally open contacts and a coil for closing the contacts only when the coil is energized, an electrical circuit for interconnecting the power source to the load through the contacts only when the contacts are closed, and a control unit for causing the coil to close the contacts substantially at a certain point on the voltage wave cycle each time the relay coil closes the contacts from the open condition thereof whereby the current flow through the contacts at each closing thereof is at substantially a desired level thereof.

Abstract: A circuit comprising a switch series connected to a load; a first and second current recirculating branch alternately connectable parallel to the load, for reducing the current in the same; and a logic control unit for opening and closing the switch and recirculating branches, so that the load is supplied with a current rising to a peak value and then falling rapidly to and oscillating about a lower hold value; a transistor being provided for reducing the voltage supplied to the load by the first recirculating branch at the end of the fast fall phase, so as to eliminate uncontrollable operating zones and prevent the load current from falling below the hold value.

Abstract: A power conservation circuit for a battery-powered voltage inverter is capable of conserving battery power. In a first embodiment, the circuit includes a switch, connected between the input terminals and the output terminals, for switching the circuit between an ON state wherein AC voltage is connected to the output terminals, and an OFF state wherein the inverter is disconnected from the battery. A first sensor senses in the ON state the absence of a load connected to the output terminals and switches the circuit from the ON state to the OFF state. A second sensor senses in the OFF state the presence of a load connected to the output terminals and switches the circuit from the OFF state to the ON state. The switch includes a relay having a pole terminal connected to the output terminals, a first contact terminal connected to the AC output of the inverter, and a second contact terminal connected to battery voltage.

Abstract: The coil holding current of a contactor is regulated to the lesser of two measurements of coil current during each cycle of the full-wave rectified control voltage to compensate for induced flux in the coil generated by load current through the main contacts of the contactor, thereby preventing uncontrolled drop out of the contactor.

Abstract: A circuit configuration for actuating a safety relay (1) such as the main relay of an electronically controlled brake system of an automotive vehicle at least has two transistors (T1, T2) connected in series and a monitoring circuit (5) which will urge the transistors into the non-conductive state if there is a defect or trouble. The operativeness of the transistors (T1, T2) or of the monitoring circuit (5) will cause the safety relay (1) to be switched off.

Abstract: A control system for applying power to a solenoid operated valve in a well completion within a borehole. The control system includes a programmable power supply for selectively applying electric power to a solenoid coil of the valve. The control system operates to apply a higher value of current to the solenoid to open the valve and a second lower value of current to maintain the operation of the solenoid in an open state and also to interrupt all current to the solenoid to close the valve. A timer controls the length of time the higher current value can be applied to the solenoid if the valve does not open and the length of delay time which must be included before again attempting to open the valve. The control system continuously monitors the state of actuation of the valve by means of an inductance monitor for determining the position of the armature of the solenoid and, thus, the state of the valve.

Abstract: Disclosed is a circuit device enabling an electromagnetic switch to be used with an A.C. power source. And the coil is thereof provided with a more stable electromagnetic field. The circuit device includes a releasing voltage detecting circuit, an engaging voltage detecting circuit, an nonstandard AND gate circuit connected to the detecting circuits, and a coil-holding circuit connected so that when there is an engaging voltage in the circuit device, the electromagnetic switch is energized and the coil is kept in a holding state. When there is a releasing voltage, the switch is de-energized.

Abstract: A switched power circuit selectively connects an electrical load to any one of a plurality of branch power circuits. The switched power circuit includes a sensing circuit for sensing electrical loading on each of the branch circuits. A logic circuit is coupled to the sensing circuit for selecting one of the branch circuits to be connected to the load according to the sensed loading to provide balanced loading on each branch circuit.

Abstract: Power dissipation across the coils in a relay control system is controlled by regulating the voltage across all the coils with a regulator that senses the voltage and varies the conduction time of the switch carrying the total coil current. The regulator includes timing and logic elements that sense if the switch is operating correctly. Another switch is operated by the logic elements to shunt the first switch when the first switch is not operating correctly. This ensures that normal coil function is available in the event of a first switch failure.

Abstract: The invention provides an electrical connector network for coordinately controlling multiple electrical appliances connected to the network. The network comprises a control outlet connected to an electrical power inlet, at least one slave outlet, and means responsive to current flow to the control outlet for selectively connecting the slave outlets to the power inlet, whereby power is available at the slave outlets only when current flows through the control outlet. In a preferred embodiment, the invention includes a current transformer for sensing current to the control outlet, the transformer producing a secondary current which is conditioned by an amplifier to drive a power triac, actuating a relay controlling power to the slave outlets. The connector network may be embodied in various structures, including extension cords, power strips, wall outlets or electrical appliances.