Abstract: A circuit interrupting device including one or more line terminals for connecting to an external power supply, one or more load terminals for connecting to an external load, one or more contacts electrically connecting one or more line terminals to one or more load terminals, and an auto-monitoring circuit. The auto-monitoring circuit configured to monitor one or more signals to determine an operating state of said circuit interrupting device, output a first signal having a first voltage level based on the operating state, wherein the first voltage level is greater than zero volts, and output a second signal having a second voltage level based on the operating state, wherein the second voltage level is greater than the first voltage level.

Abstract: Provided is an injector control unit capable of preventing unintended fuel injection other than an engine drive period. The injector control unit includes a cutoff mechanism for cutting off current supply to the injector from at least the ignition OFF to the next ignition ON.

Abstract: An injection control device includes a boost controller performing boost control of a boosted voltage generated by a booster circuit until a boosted voltage, which is generated in a boost capacitor, rises to a full-charge threshold when the boosted voltage falls below a charge start threshold. When, for stopping a peak current by a drive unit, a power interruption controller interrupts electric current supplied to the fuel injection valve by the drive unit as interruption control (i) of an application voltage to a fuel injection valve or (ii) of a constant current by the drive unit, a regeneration unit regenerates electric current generated in the fuel injection valve to the boost capacitor of the booster circuit. The boost controller upward-shifts (i.e., raises) the full-charge threshold of the booster circuit.

Abstract: A method is provided for forming a three-dimensional article through successively depositing individual layers of powder material that are fused together so as to form the article. The method includes: providing at least one electron beam source emitting an electron beam; providing a leakage current detector for sensing a current through the anode and/or the Wehnelt cup; providing a low impedance voltage source connectable to the Wehnelt cup via a switch, where the voltage source is having a more negative potential than a negative potential applied to the cathode; and protecting the cathode against vacuum arc discharge energy currents when forming the three-dimensional article by providing the Wehnelt cup to the low impedance negative voltage by closing the switch when the leakage current detector is sensing a current through the anode and/or the Wehnelt cup which is higher than a predetermined value.

Abstract: A step-by-step electric relay structure of a bistable type, comprising a mechanical part and an electric part, the mechanical part comprising push-button means to be operated by a user and the electric part comprising coil means, capacitor means, resistor means and diode means operatively interconnected to one another, the coil means comprising either two coils coupled in parallel to one another or a single coil polarized or biased with two polarities, thereby, as the push-button means are operated by the user to provide a switching or exchanging of at least a contact of the relay structure, either one of the two coils is shorted or the two polarities of the single coil are mutually reversed, thereby providing the electric relay structure with a logic SET function and a logic RESET function.

Abstract: A fuel injection control system is usable with an engine, e.g., a diesel engine of a mild hybrid electric vehicle. The control system includes an auxiliary battery, a high-voltage (HV) battery, e.g., 48 VDC, a switching circuit with first and second switching pairs, a controller, and a fuel injector system. The controller opens and closes the switches to command an electrical current from the auxiliary or HV battery according to a predetermined injector current profile. The fuel injector system has one or more control solenoids. Windings of the solenoids are electrically connectable to the HV battery during a boost phase of the profile via opening of the first switching pair and closing of the second switching pair, and to the auxiliary battery during peak, by-pass, hold, and end-of-injection phases of the profile via closing of the first switching pair and opening of the second switching pair.

Abstract: An anti-interference switch signal transmission circuit, in which a changeover switch is used at a signal terminal, is disclosed. A normally closed contact is connected to DC?, a normally open contact is connected to DC+, and a common contact is connected to a switch signal acquisition circuit. When no signal exists, DC? is provided to a positive input terminal of the switch signal acquisition circuit via the normally closed contact. Since a negative input terminal of the switch signal acquisition circuit is also connected to DC?, even if interference is caused, no false signal is generated. When a signal exists, the position of the changeover switch changes and DC+ is connected to DC? via the closed normally open contact through the switch signal acquisition circuit thus a loop is formed, so that the signal can be detected.

Abstract: A method performed in a control unit for opening a contactor device. The contactor device includes a carrier being movable between a closed position in which a current is allowed to flow in a current path and an open position in which the current path is broken. The control unit is configured to enable the movement of the carrier between the closed position and the open position by energizing a coil of an electromagnetic circuit. The method includes: initiating the opening of the contactor device by de-energizing the coil, wherein the de-energizing includes using a demagnetization circuit including a discharge element, the discharge element being arranged to consume energy in the coil; bypassing, at a first point of time, the discharge element; and re-energizing the coil.

Abstract: The present disclosure is directed to an automated apparatus and method for testing a crowbar circuit of power converter. The crowbar circuit includes an anti-parallel diode and a voltage-controlled switching element, e.g. a silicon-controlled rectifier (SCR). The method includes implementing a first test sequence for testing operability of the diode and a second test sequence for testing operability of the voltage-controlled switching element. More specifically, the first test sequence determines a first current-voltage feedback that is indicative of the operability of the diode and the second test sequence determines a second current-voltage feedback that is indicative of the operability of the voltage-controlled switching element.

Abstract: An apparatus for reducing or minimizing disturbance signals in the case of a field device of process automation, wherein the field device has a control/evaluation unit and a sensor, with, respectively, at least one main electronics and at least one sensor electronics. At least one data line is provided, via which the main electronics and the sensor electronics communicate. At least one galvanic isolating component is provided, which is integrated into the at least one data line, and which prevents transmission of disturbance signals via the one or more data lines. Power supply lines are provided, via which a power supply voltage sufficient for operation of the sensor is made available to the sensor; and wherein, in the power supply lines, filter means are provided, which are designed in such a manner that predetermined requirements for disturbance resistance of the power supply lines are fulfilled.

Abstract: A method is proposed for actuating an electromagnetic load (3) which can be switched between at least two switching states, particularly a magnetic valve, wherein switching between a first and a second of the switching states takes place as a result of a current flowing through the load (3) by means of applying an electrical voltage to said load (3). Provision is thereby made for the voltage to be clocked upon application thereof to said load (3) if due to the applied voltage the switching process would occur without clocking outside of a current ramp-up. The invention furthermore relates to an electrical circuit for actuating an electromagnetic load (3).

Abstract: A power supply diagnostic circuit includes a switching power supply that generates a voltage for powering a fuel injector. An injector control module selectively applies the voltage to the fuel injector and monitors a resultant electrical current flow through the fuel injector. The switching power supply includes a dual path circuit comprising two inductors, two MOSFETs, and two diodes. The injector control module determines whether one path of the dual path circuit is defective based on the electrical current flow.

Abstract: A solenoid valve control device is provided with: a first relay connected in series to a drive coil of a solenoid valve between output terminals of a rectifier circuit; a photocoupler configured to output a voltage of a GND level when a current equal to or greater than a predetermined level is flowing in a contact in the first relay and output a voltage of a V5 level when the current equal to or greater than a predetermined level does not flow in the contact in the first relay; and an integration circuit configured to smooth an output voltage Va1 from the photocoupler. When an output voltage from the integration circuit is not greater than a first threshold value, a microcomputer detects that the first relay is in an on state.

Abstract: A fuel injection control for an internal combustion engine includes a coil, a first switch, a capacitor, a second switch, and a control circuit. The coil is to boost a voltage of a power supply source. The first switch is connected at one end to an output side of the coil and at the other end to a ground. The capacitor is connected to an electromagnetic fuel injection valve to store energy which has been stored in the coil. The second switch is connected at one end between the coil and the first switch and at the other end to an input side of the capacitor. The control circuit is connected to the first switch and the second switch. The control circuit is configured to perform synchronous rectifying control for switching the first switch and the second switch.

Abstract: An over-voltage protection circuit is disclosed herein for protection against over-voltage of an energy storage device while charging. The circuit operates within the operational limits of a battery-operated device, such as a mobile or handheld device. The over-voltage protection circuit comprises an over-voltage protection device, and an over-voltage protection controller. The controller allows current to flow to the over-voltage protection device only when an energy storage device is experiencing over-voltage. In allowing current to flow to the over-voltage protection device only when the voltage across the energy storage device is above a predetermined voltage, power conservation is achieved.

Abstract: A capacitor 16 is charged by turning on a switching element 12, and when a relay 18 is operated, by turning off the switching element 12 and turning on a switching element 13, a constant-voltage power supply 11 and the capacitor 16 are series-connected, and a switching element 14 is turned on to cause the series circuit of the constant-voltage power supply 11 and the capacitor 16 to be connected to a relay coil 20, so that the voltage resulting from addition of the output voltage of the constant-voltage power supply 11 and the charging voltage of the capacitor 16 is supplied to the relay coil 20, whereby causing the relay 18 to be turned on, after which the capacitor 16 is gradually discharged by means of the relay coil 20.

Abstract: A voltage generator used to generate a voltage for driving a vehicle fuel injector includes a microcomputer, a coil, and a capacitor. The microcomputer calculates an interval at which the fuel injector is driven. When the interval is less than or equal to a predetermined time period, the microcomputer causes a first current to flow through the coil so that the capacitor is charged to a first level by counterelectromotive force produced in the coil. When the interval is greater than the time period, the microcomputer causes a second current less than the first current to flow through the coil so that the capacitor is charged to a second level less than the first level. The fuel injector is driven by the capacitor voltage.

Abstract: An engine control unit for controlling an automobile engine, which is equipped with a booster circuit for boosting the voltage of battery power source, an injector driving circuit for driving an injector by making use of a boosted high voltage, and a microcomputer for controlling the engine; wherein the engine control unit is featured in that an LC module mounted with a booster coil constituting the booster circuit and with an electrolytic capacitor, a power module mounted with a rectifying device constituting the booster circuit and the injector driving circuit and with a switching device, and a control circuit board mounted with the microcomputer and with a connector acting as an interface for an external member of the engine control unit are laminated each other.

Abstract: A power switching control apparatus for acquiring pieces of making operation time information of individual phase switches more precisely according to loads and making instants. Making operation time information detecting means outputs the making operation time information of at least one of individual phase switches on the basis of the motion of the movable contact of the phase switch, and outputs the making operation time information of at least another of the individual phase switches on the basis of the phase current of the phase switch. Moreover, the making operation time information detecting means outputs the making operation time information ITA, ITB and ITC of an A-phase switch, a B-phase switch and a C-phase switch individually on the basis of either the detected output of a contact operation sensor and the detected output of a phase current sensor.

Abstract: In a voltage boost circuit for driving a fuel injector of an internal combustion engine, a high voltage developed in the voltage boost coil will be discharged into the battery power supply through the boost coil by electrically energizing a discharge switching element provided in parallel to the charging diode. If the overboost compensation overlaps a boost execution period, the end of the boost execution period will await starting of the overboost compensation.

Abstract: An electric supply circuit is provided for a switch actuating device containing an actuator, an electromagnetic drive for displacing the actuator from a first switching position to a second switching position, and a mechanical return device for returning the actuator from the second switching position to the first switching position. A magnetic fixing unit is provided for fixing the actuator in the second switching position and an electromagnetic releasing device is provided for releasing the fixation. The electric supply device contains a first capacitor electrically connectable to the electromagnetic drive and used for supplying electric power thereto and a second capacitor that is electrically connectable to the releasing device and supplies electric power thereto for releasing the fixation. An electric switchable connection is provided between the first and second capacitors.

Abstract: In a method for sorting PTC elements having different resistance-temperature characteristics, a predetermined voltage that allows a current to sufficiently decay is applied to each of PTC elements A and B, and the PTC elements are sorted on the basis of the difference between the times required for the currents passing through the PTC elements B to reach a predetermined value (e.g., 52 mA).

Abstract: A switching device of a chopper circuit is interrupted from a switching circuit when the switching device has a breakdown, whereby power source input is directly output without being boosted by chopper operation. A motor controller provided to ECU of an electrically-driven power steering device is equipped with a chopper circuit for carrying out a voltage boosting operation, a detection circuit for detecting a failure of a first switching device TR1 in the chopper circuit, and an interrupting relay switch. A controller carries out ON/OFF control on the first switching device, and when the detection circuit detects the failure of the switching device, the controller turns off the interrupting relay switch, and separates the first switching device from the chopper circuit. At this time, the battery voltage Vin is output as an output voltage Vout without being boosted by the chopper circuit.

Abstract: A switch monitoring circuit includes a switch arranged to be turned ON/OFF in response to an operation, a capacitor connected to both ends of the switch, a voltage applying unit that applies a voltage to the switch in response to a command, a voltage detecting unit that detects the voltage applied to the switch and a diode connected to the switch and the capacitor. The diode prevents an electric charge stored in the capacitor from being emitted.

Abstract: A field discharge circuit may rapidly reduce the field current of a generator, thereby avoiding an overvoltage condition. The field discharge circuit of the present invention may use another storage device, such as a capacitor, to quickly transfer the field current energy thereto and then slowly dissipate the transferred energy after the event (such as removal of a load) has passed. By transferring this energy to a storage device and subsequently slowly discharging this energy through a resistor, electromagnetic interference caused by a conventional resistive discharge can be reduced.

Abstract: In a direct-current voltage-driven magnetic contactor, a main contact is in an open circuit condition in an attraction period of an initial period of excitation by an operating coil, and in a closed circuit condition in a subsequent holding period, and a drive circuit includes a direct-current power supply voltage detecting circuit that gives a start signal when an applied voltage of a exciting direct-current power supply exceeds a predetermined value, a first drive circuit that makes a starting semiconductor switching element perform an ON operation on receiving the start signal, and a second drive circuit that makes a current limiting semiconductor switching element perform a switching operation when a terminal voltage of a charging capacitor reaches the predetermined value.

Abstract: The present invention is a kind of switch device for the control of two sets or above two sets of electromagnetic actuator, driving coil such as electromagnetic brake, electromagnetic clutch, electromagnetic switch, and electromagnetic valve, etc. for parallel actuation, so as to generate better electromagnetic actuation power, and through the control of switch device, take driving coil switch in parallel to reduce the current of driving coil, but still maintain electrically actuated operation in order to save electricity and reduce the generation of heat of electromagnetic actuator.

Abstract: Prior to the operation of a solenoid type of fuel injector, a DC voltage is applied across the injector to create a current through the injector that is below the activation current of the injector. A capacitor is then placed in series with the injector and the flyback energy from the injector transfers a charge onto the capacitor. When the injector current drops to a predetermined level, the capacitor is removed from the circuit and isolated. This process is repeated until a minimum charge is on the capacitor. By placing the capacitor charge onto the injector at the time that the injector is to be activated, the opening response of the injector is improved. By applying the charge on the capacitor to the injector in a manner to neutralize the eddy currents when the voltage across the injector is removed, the closing response is improved.

Abstract: When a sine wave is supplied from a sine wave oscillator through a resonant capacitor selection circuit, an alternating electric and magnetic field is generated on a loop coil. A magnetic intensity detection coil supplies an electromagnetic field signal to a control circuit when detecting electromagnetic intensity of the loop coil. The control circuit controls the resonant capacitor selection circuit based on the electromagnetic field signal and adjusts a maximum current to flow into the loop coil. Namely, a resonant capacitor with a suitable capacitance is selected in such a way that a resonance point (for example, 125 kHz) reaches a maximum level. Moreover, the control circuit adjusts a variable resistor to obtain a target electromagnetic field signal (intensity of electromagnetic field) in this state. Namely, automatic gain control is performed to obtain optimal electromagnetic field intensity on the loop coil.

Abstract: A safety control circuit for a direct current electromotive nail driver comprises: a direct current power source for supplying power to the circuit; a control and protecting unit having a security switch, a trigger switch and a stop switch; and a motor for driving an object. When the security switch is turned on and then the trigger switch is pressed, the control and protecting unit will receive a signal from the trigger switch so as to conduct the motor and thus the motor operates to drive an object. When the motor operates through a predetermined time period, the stop switch will actuate a protection function of the control and protecting unit so that the motor cannot operate until the security switch is actuated again.

Abstract: A control apparatus for master/slave outlets having a current sensor, a driver, a large current switch component and a direct-bucking type power supply such that the working power source required by the master/slave equipment can be supplied stably. Further, the control apparatus for master/slave outlets provides a most simplified circuit to perform a function that the slave outlet supplies a power at the time the master outlet is supplied the power.

Abstract: A drive apparatus supplies electric power to a solenoid of an inductive load from a battery and a capacitor to improve response of the load. The drive apparatus comprises switches for switching between a first state where a negative side of the battery is connected to a positive side of the battery, and a second state where the negative side of the capacitor is connected to the negative side of the battery. When the load is in operation, the voltage applied to the solenoid is raised by the voltage of the battery as the first state, so that the current flowing into the solenoid rises sharply to improve response of the load. When the operation of the load is to be stopped, the electric power to the solenoid is interrupted, and the energy accumulated in the solenoid is recovered by the capacitor as the second state.

Abstract: The invention relates to a system for pulse magnetizing high-precision magnetic scales. The system comprises a shaped current conductor (1) and a pulse current source (2) that is composed of a capacitor bank (3), a transfer switch (4) and a control unit (5). The compact set-up of the system is the prerequisite for a power circuit that has such a low resistance that the required high pulse currents are obtained at supply voltages of below 60 V. The transfer switch is an H bridge with four switches (7) that contain equal numbers of MOS transistors connected in parallel. The short pulse times that are achieved using the MOS transistors allow the use of shaped current conductors with which magnetized areas can be produced with a very high precision. The inventive system provides a means for saving components, electric power and time by a factor of up to 100.

Abstract: Electrostatic discharge can damage electronic equipment. It has been known to start a fire when it occurs when a motor vehicle's gasoline tank is being filled. A device for detecting, alarming, and/or neutralizing an electrostatic charge can help avoid these problems. A variable capacitor, the capacitance of which is made to vary periodically, is used to detect electrostatic charge. A first electrode of the capacitor is the object for which electrostatic charge is important. The capacitor's electrode is one by which the capacitance is varied. An amplitude of a signal from the electrode can be shown to be proportional to the electrostatic charge on the object.

Abstract: There is suggested a simple and cost-economical circuit arrangement for specifying the current through an inductive component, in which the inductive component is acted on by the supply voltage through a switching element. To ensure a rapid and reliable increase of the current in a first phase of the current supply phase, the inductive component is acted on by a constant voltage generated by a constant voltage source during the first phase of the current supply phase, and is acted on by the supply voltage during a subsequent second phase of the current supply phase.

Abstract: A bulk degaussing apparatus and method for erasing magnetic media of various sizes. A media passage track is provided such that media passing therethrough is uniformly exposed to the magnetic fields provided through the gap. The bulk degaussing apparatus has fixed magnetic pole pairs predisposed for generating uniform magnetic field elements across a gap projecting magnetic flux across the gap for erasing various sizes of magnetic media, with the magnetic media receiving track positioned relative to the poles such that adjacent like poles are arranged on each side of the gap to counteract fringing effects. The bulk degaussing method for erasing various sizes of magnetic media provides a plurality of fixed magnetic pole pairs for generating uniform magnetic field elements on one or more sides of a degaussing region projecting magnetic flux into the region, and arranges the plurality of fixed poles so that adjacent poles counteract fringing effects.

Abstract: A power supply for an electromagnetic force system comprising a slow current pulse system in parallel with a dumping circuit feeding a blocking inductor in parallel with a series of diodes; a fast current pulse system of opposing polarity and parallel to the slow current pulse system and blocking inductor, the fast pulse system including a triggered vacuum spark-gap for discharging the fast current pulse system through a working coil such that the current through the coil decreases rapidly and the magnetic field in the gap decreases substantially while the magnetic field in and behind the work piece decreases only slightly, resulting in a large field gradient across the work piece and the creation of a pulse of tension force on the work piece.

Abstract: A safety circuit according to the invention controls operation of an equipment load. A manual control switch of the safety circuit is connected in series with the equipment load for controlling the flow of electrical current to the equipment load. The equipment load and control switch series combination are further in communication with a relay contact switch of the safety circuit, which, like the manual control switch controls the flow of electrical current to the equipment load. Arranged in this configuration the equipment load operates only if both the mechanical switch and relay contact are closed. If either the manual control switch or the relay contact are open, the equipment load does not operate.

Abstract: A method and a device are proposed for driving a solenoid valve that has stroke ranges of a stable equilibrium of forces and stroke ranges of an unstable equilibrium of forces. For setting the predetermined differential pressure across the solenoid valve, a driving signal quantity is generated which is selected such that the stroke ranges of an unstable equilibrium of forces are avoided or the dwell time of the solenoid valve in these ranges is reduced.

Abstract: In an electromagnetic injector control apparatus for an engine, a capacitor is connected to a power supply and a solenoid of an injector for accumulating electric charge at a voltage higher than that of the power supply. A driving circuit controls transistors to supply energy from the power supply to the solenoid during an operation period of the solenoid. The driving circuit also controls a transistor so that a timing to start supplying the accumulated energy from the capacitor to the solenoid is delayed from a timing to start the operation of the solenoid as the voltage of the capacitor increases. Thus, the accumulated energy is used to speed up the operating response of the solenoid. The supply of the accumulated energy to the solenoid is stopped when a current flowing in the solenoid reaches a predetermined cut-off level.

Abstract: A method and device for driving at least one electromagnetic load, in particular a solenoid valve, for controlling an injection of fuel into an internal combustion engine, using a drive circuit equipped with an electronic switching device and at least one booster capacitor. The booster capacitor includes a recharging device that recharges a voltage of the booster capacitor to a desired voltage value influencing an opening speed of the solenoid valve, and thus an injection time, each time the booster capacitor is partially or completely discharged. The recharging device is functionally connected to a detecting device for detecting at least a speed and a load of the internal combustion engine. The recharging device includes a regulating device that regulates an intensity of a recharging current needed for the desired voltage value and the necessary recharging time, at least as a function of the speed and the load detected by the detecting device.

Abstract: The control device comprises a piloting circuit for the electroactuators and a timing circuit which generates timing signals supplied to the piloting circuit for control of the electroactuators. The piloting circuit has a first and a second input terminal which are connected in use respectively to a first and a second terminal of an electrical energy source, and a plurality of pairs of output terminals, one for each electroactuator; each pair of output terminals comprising a first and a second output terminal, between which a respective electroactuator is connected in use. The piloting circuit comprises a plurality of control circuits, one for each electroactuator, which receive as input the timing signals and are activated selectively by the timing signals themselves.

Abstract: A method of increasing a cast-off speed of an armature from a pole of an electromagnet of an electromagnetic actuator, includes the following steps: holding the armature at the pole against a force of a resetting device by maintaining an electric holding current flow through a coil of the electromagnet; and launching the armature from the pole by switching off the holding current; and at a predetermined moment during a release period of the armature from the pole, passing a cast-off current for a predetermined period through the coil. The cast-off current has a polarity opposite to the polarity of the holding current.

Abstract: A method and a device for controlling a load, in particular a solenoid valve for controlling the quantity of fuel to be injected. The load receives a bias current value before being activated. This bias current value is adapted.

Abstract: A circuit for driving an electromagnetic solenoid valve, used as a fuel injector in an internal combustion engine, having a needle valve biased in a closing direction by a spring and a solenoid which moves the needle valve in an opening direction when energized to inject fuel into a cylinder of the engine. The circuit includes a first booster which boosts battery voltage to a first voltage to charge a capacitor. The charged voltage is applied to the solenoid for a time period to cause the needle valve to move in the opening direction. The circuit includes a second booster which boosts the battery voltage to a second voltage, less than the first voltage, to be supplied to the solenoid to maintain the first current, enabling the period of large current application to be freely determined to ensure reliable valve operation, whereby the fuel injection can be reliably effected.

Abstract: An injector drive circuit capable of driving an injector of an internal combustion engine without using a DC-DC converter expensive. The injector drive circuit includes a power circuit for converting a voltage outputted from a magneto mounted on the engine into a DC voltage, a capacitor charged with a voltage accumulated in a voltage accumulator, a drive current feed circuit for applying a voltage across the capacitor to a solenoid coil to feed a drive current to the solenoid coil when it is fed with an injection command signal, and a holding current feed power supply section for feeding the solenoid coil with a holding current required for keeping a valve open after the drive current fed from the capacitor to the solenoid coil passes a peak value.

Abstract: There is proposed a circuit for operation of at least one relay having an OFF-position and an ON-position, wherein the relay assumes the OFF-position in the event of a component failure of any element of the circuit. In the ON-position of the relay a capacitor, the relay and a voltage source are switched in a predetermined cycle in such a way that in a first time interval of the cycle the voltage source delivers a current which flows through the relay and partially charges up the capacitor and that in a second time interval of the cycle the capacitor delivers the current which flows through the relay, with the capacitor being partially discharged again.

Abstract: A control circuit for a latching solenoid incorporated in an electric door strike, the latching solenoid permitting the use of low power control pulses and the control circuit insuring reliable fail safe or fail secure operation with ready conversion between the two operating modes.

Abstract: A solenoid valve drive system includes a step-up circuit that produces a first high voltage by using a switching device to on/off control supply of current from a battery to a step-up coil and stores the first high voltage in a first capacitor as a high voltage for initial high-voltage driving of a solenoid valve, a second capacitor, and a discriminating circuit for discriminating the level of the charge voltage of the second capacitor. The second capacitor is charged by high voltage from the step-up circuit only when the charge voltage of the second capacitor has not reached a prescribed level. The system can efficiently produce two types of high voltages without enlarging circuit size.

Abstract: A control circuit for an electromagnetically operable fuel control valve of a vehicle engine includes a tank capacitor which upon closure of first and second controllable switches supplies current to the winding of the valve to achieve a high rate of rise of current in the winding and rapid operation of the valve. Following operation of the valve it is maintained in its operated state by current chopping action, the current rise being achieved by drawing current from a low voltage source through a third controllable switch. The current fall is at a high rate and the resultant high voltage induced in the winding is utilized to recharge the tank capacitor.