Abstract: A control circuit and method for a single coil magnetic latching relay is provided in the present disclosure. The circuit includes: a first control circuit (21) and a first single coil magnetic latching relay coil (22). The first control circuit (21) includes: a first transistor (211), a first diode (212), a second diode (213), a first capacitor (214), a second capacitor (215), a first resistor (216) and a second resistor (217) and the first control circuit (21) is configured to control the first single coil magnetic latching relay coil (22) to enter a preset state and/or maintain the preset state.

Abstract: A building automation system that is comprised of a plurality of network connected electrical modules contained in standard receptacle gang boxes for outlets and switches is described. The system includes an AC to DC power supply, a bidirectional solid stale dimmer switch, a microprocessor, and, interconnected sensors that are powered and controlled by microprocessors within the electrical modules. The electrical modules include a user interface for programming and control. The system provides enhanced safety and security, power metering, power control, and home diagnostics. The apparatus replaces existing outlet receptacles and switches with a familiar flush but elegantly updated and seamlessly integrated faceplate.

Abstract: An electrically operated valve system includes: a first switching element and a second switching element connected in series to an electric power supply; a third switching element and a fourth switching element connected in series to the electric power supply; diodes; a coil connected between a first middle point and a second middle point, the coil being wired such that a valve opens when the second switching element and the third switching element are opened and the first switching element and the fourth switching element are closed; a shutoff switch configured to shut off a path between a positive electrode of the first switching element and the electric power supply; and a capacitor connected at one end of the capacitor between the shutoff switch and the first switching element and connected at the other end of the capacitor to the negative electrode of the electric power supply.

Abstract: The present application discloses systems and methods of powering a solenoid circuit and other circuits with batteries that are at (or near) the end of their functional life.

Abstract: The magnetic resistance of a magnetic path that passes through a coil (6) is increased by magnetically dividing a stator core into a plurality of divided cores (4, 5) in such a manner that the magnetic flux of a permanent magnet (7) flows through the magnetic path when a projection (82) of a plunger (8) magnetically connects the divided cores (4, 5), hence the magnetic resistance of the magnetic path that passes through the coil (6) rapidly changes due to a positional relationship between a gap between the divided cores (4, 5) and the plunger (8), and the magnetic flux that flows through the magnetic path rapidly changes, and moreover a large back electromotive force is produced.

Abstract: A latching relay drive circuit includes a transistor that goes off when an operation switch is open, and a transistor connected in parallel to a capacitor and an operation coil. The transistor comes on when the transistor goes off to allow a reset current to flow into the operation coil. Accordingly, an enough reset current can be supplied, even if a power supply is shut off due to a power failure, to securely recover a single winding latching relay.

Abstract: A control device actuates at least one fuel injection valve with a high voltage and a comparatively lower voltage in temporally consecutive phases. The control device has supply connections for supplying energy from a motor vehicle battery. One of the connections is connected to vehicle ground. First output connections provide a positive first output voltage with respect to vehicle ground, the voltage being smaller than or equal to a hazard voltage of 60 volts of direct current according to TRBS2131. Second output connections provide a positive second output voltage with respect to vehicle ground, the voltage being greater than the hazard voltage and smaller than a sum of the first output voltage and the hazard voltage. The positive potentials of the first and second output voltages (U1, U2) are linked together.

Abstract: A thermostat, of the type that employs latching relays to connect thermostat power to the various wires of the thermostat run, has a re-pulse feature that supplies latching pulses at a given interval, e.g., three hours, to ensure that the relays are in their proper state agreeing with the thermostat mode and the room temperature relative to the setpoint(s). In the case that the room air temperature is changing in a manner contrary to the current heating or cooling mode, which may indicate the latching relay has been knocked or bumped and needs to have its proper state re-established, the thermostat microprocessor issues pulses to the latching relay(s) more frequently, e.g., each 30 minutes, and the re-pulses may have a longer pulse width, e.g., increased from 20 ms to 25 ms.

Abstract: The disclosure relates to a circuit arrangement for actuating a bistable relay including a relay coil of the bistable relay being arranged in a series circuit with a capacitor, wherein the series circuit is connected to a supply voltage (V+) via a first semiconductor switch for switching on the bistable relay and is short-circuited through a second semiconductor switch for switching off the bistable relay. The circuit arrangement includes at least one voltage regulator configured to regulate the voltage present at the relay coil of the bistable relay such that a preset voltage is not exceeded.

Abstract: A solenoid pump, including: an inlet port, an outlet port, and a first through-bore connecting the inlet and outlet ports; a plunger disposed within the first through-bore and including a second through-bore; a spring arranged to urge the plunger toward the outlet port; a solenoid coil disposed about a portion of the plunger and arranged to displace the plunger toward the inlet port in response to coil power applied to the solenoid coil; and a control unit for: accepting an input voltage; generating the coil power during an interval equal to a first time period; supplying the coil power to the solenoid coil; and selecting a duration of the first time period such that the duration of the first time period varies according to the input voltage.

Abstract: A forward converter comprises a magnetic component with a transformer and a filter output inductor. Also disclosed is a method for assembly of a forward converter. A first and a second U/UR core are arranged to form an O-core. Windings of the transformer are arranged on the O-core. A bobbin-less U/UR core is arranged to abut the O-core, and windings of a filter output inductor are arranged directly on a body section of the bobbin-less U/UR core. Alternatively, windings of the transformer are arranged on a first section of an E/ER core, and windings of the filter output inductor are arranged directly on a second, bobbin-less section of the E/ER core.

Abstract: A drive circuit for a DC latching device includes a battery, a storage element, and a plurality of switches connecting the battery to the storage element for charging the storage element from the battery and discharging the storage element into the coil of a DC latching device. The drive circuit further includes components for determining a state of the DC latching device. The drive circuit may include components for terminating the discharge of the storage element into the coil of the DC latching device in response to determining that the DC latching device has changed states to add reliability to the system and reduce energy consumption.

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 method for discharging an industrial lifting magnet quickly without producing a high voltage transient is presented. Most of the stored magnetic energy is dissipated in the magnet itself by connecting a diode across the magnet in the appropriate direction at discharge time using switching devices. One variation, suitable for smaller magnets, discharges the remaining energy using DC capacitors and a diode switching network. Another variation, suitable for magnets of any size, discharges most of the remaining energy in a power resistor of modest size using a system of diodes and switching devices in conjunction with a relatively small AC capacitor across the magnet.

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 bistable electromagnetic actuator comprising a magnetic circuit comprising a magnetic yoke in which a shunt extends perpendicularly to a longitudinal axis of said yoke and comprising a permanent magnet positioned between a first surface of the yoke and the shunt. A plunger core is fitted with axial sliding between a latched position and an unlatched position. A coil extending between the shunt and a second surface of the yoke is designed to generate a first magnetic control flux to move the plunger core from an unlatched position to a latched position. A second magnetic control flux enables the plunger core to move from the latched position to the unlatched position by the action of a return spring.

Abstract: A system and method for providing an intrinsically safe (IS) circuit for driving a solenoid valve at a low power is disclosed. A voltage source generates a first voltage and is connected to a first side of the solenoid valve. A voltage inverter is connected to the voltage source and generates a second voltage from the first voltage. The second voltage is of opposite magnitude to the first voltage. A controller selectively controls the first voltage and the second voltage to be applied to the solenoid valve. In order to actuate the solenoid valve, the first voltage is applied to the first side of the solenoid valve and the second voltage is applied to the second side of the solenoid valve. In order to hold the solenoid valve in an on position, the first voltage is maintained and the second voltage is no longer applied to the second side of the solenoid valve.

Abstract: A charging control apparatus comprising: a voltage control unit in a charging apparatus configured to control generation of an output voltage and a power supply voltage, the charging apparatus being an apparatus configured to generate, from a voltage of an input power supply applied through a relay, the output voltage for charging a battery and the power supply voltage for control; and a relay control unit operated by the power supply voltage, the relay control unit configured to drive the relay so as to stop applying the voltage of the input power supply to the charging apparatus, when detecting a standby state in which the battery is not being charged, and drive the relay so as to increase the power supply voltage by applying the voltage of the input power supply to the charging apparatus, when the power supply voltage decreases below a predetermined level.

Abstract: An electronic triggering unit for an electromagnetically actuated valve is disclosed, in which the valve is provided in particular for a hydrostatic displacement unit. The electronic triggering unit has a first switching device, which during the attraction phase of the valve applies a first voltage to its coil, which voltage is higher than the operating voltage of the electronic triggering unit. This first voltage is obtained from the operating voltage by means of a voltage-increasing circuit. A second switching device, during the maintenance phase of the valve, applies a second voltage, which corresponds approximately to the operating voltage, to its coil. According to the invention, the voltage-increasing circuit is a booster circuit, which in response to a corresponding trigger signal charges a buffer memory to the increased first voltage.

Abstract: A fast turn-off and fast turn-on circuit (10) providing at least one power source (12, 20), at least one switching device (14, 22), a coil (16), and at least a first voltage control device (18). The at least one switching device (14, 22) is connected to the at least one power source (12, 20) for selectively connecting the at least one power source (12, 20) to portions of the circuit (10). An electrical current from at least one power source (12, 20) charges the coil (16) and creates an electromagnetic field when the at least one switching device (14, 22) is in a closed position and connects the at least one power source (12, 20) with the coil (16). The first voltage control device (18) limits a voltage in the circuit (10) when the electromagnetic field decays.

Abstract: An implantable drug delivery device includes a pump motor that is driven by electrical energy from a storage capacitor. At the end of each pump delivery cycle, electrical energy stored in the pump motor is recovered and returned to the storage capacitor, so that it can be used in subsequent delivery cycles.

Abstract: An electromagnetic valve driving apparatus is provided for reducing emission noise generated when a discharge switching element is turned off. In the apparatus, a discharging capacitor stores electrical energy for performing discharge to a coil in an electromagnetic valve and charging means generates voltage from a power source voltage, which voltage is higher than that of the power source voltage. A discharge switching element is provided in series in a current path extending from the discharging capacitor to an up-stream side terminal of the coil. Controlling means turns on/off the discharge switching element. Circulating means is provided in the current path for circulation of current to the coil. Sub-discharging means is provided in the current path, for starting discharge to the coil when the discharge switching element is turned off, and for circulating current to the coil through the circulating means when the discharge to the coil is completed.

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: A bistable electromagnetic actuator comprising a magnetic circuit comprising a magnetic yoke in which a shunt extends perpendicularly to a longitudinal axis of said yoke and comprising a permanent magnet positioned between a first surface of the yoke and the shunt. A plunger core is fitted with axial sliding between a latched position and an unlatched position. A coil extending between the shunt and a second surface of the yoke is designed to generate a first magnetic control flux to move the plunger core from an unlatched position to a latched position. A second magnetic control flux enables the plunger core to move from the latched position to the unlatched position by the action of a return spring.

Abstract: The invention is directed to a circuit array with a relay (K1; K12) incorporating a field coil (E) as well as a switch contact (1a, 1b), said switch contact (1a, 1b) being provided as a switch point between a grid, in particular a mains supply (N), and an inverter (WR) fed by a direct voltage source, in particular by a photovoltaic generator (PVG), said relay (K1; K12) being configured to be a bistable relay.

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: An injector drive device includes a power supply unit that is supplied with power from a battery mounted in a vehicle and generates a voltage higher than the voltage of the battery, and EDU having a drive unit that is supplied with power from the power supply unit and drives an injector. The drive unit is housed in a housing. The power supply unit is placed externally to the EDU, that is, externally to the housing, so that the housing need not be made large against heat generation of the power supply unit.

Abstract: Circuit-breaker arrangement (32) in an indicating arrangement (33) forming part of an electrically powered stapler (1). The stapler comprises a stapling head (2) and an anvil (3). The stapling head comprises an interchangeably fitted staple cassette (5) containing staple blanks (36), and the indicating arrangement. The circuit-breaker arrangement is so positioned that it is moved by the staple cassette from a first to a second position when the staple cassette is fitted to the stapling head and when the power supply via the indicating arrangement changes. The circuit-breaker arrangement (32) comprises an input line (22) and output line (23), of which at least the input line is dimensionally stable and resiliency flexible.

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: 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: Systems and methods for valve actuation use series-connected coils of upper and lower electromagnets acting as electromagnetic generators that attempt to maintain a constant magnetic flux, while their forces are essentially independent. A valve controller initiates valve actuation by reducing holding force of the holding electromagnet. As spring force begins to move an armature away from the holding electromagnet, the associated coil generates a voltage that attempts to maintain constant flux. This generated voltage causes a large increase in current that essentially transfers the flux to the other on-coming coil, which attracts and holds the armature against its associated spring force to open or close the valve. The internal voltage generated inside the two coils operates even if the coils are supplied with zero external voltage (shorted) to transfer stored energy directly between the coils. Energy may be transferred indirectly using an energy storage device.

Abstract: A power supply method an apparatus for powering electrical equipment, the electrical equipment operated by using current peaks. The electrical equipment may be connected via at least one capacitive element to a voltage converter which may be connected to a storage battery. The voltage converter may be current-regulated from a reference current. The reference current may correspond to an average current between two peaks (generally corresponding to one cycle of operation). The reference current may be calculated in a predictive manner and the reference current may include a correction factor. The voltage output from the voltage converter may be maintained between an upper limit and a lower limit.

Abstract: In a solenoid driving device of the type in which energy stored in a capacitor is used for re-driving of the solenoid, the generation of heat in a current back-flow preventing circuit preventing the back-flow of current to a power supply terminal is suppressed, and the generation of heat in a rectifying element through which the current that flows to the capacitor passes is suppressed. Electric power accumulated in the solenoid when the driving of the solenoid is stopped is temporarily stored in the capacitor, and a high voltage that is generated by the charging utilizing the peak voltage of the capacitor is utilized as the power supply for a discharge control circuit that controls the discharge of the capacitor. The current back-flow preventing circuit is constructed from a switching element such as an FET so that the generation of heat in this circuit is suppressed.

Abstract: An electromagnetically operated device has an electromagnet including a magnetic guide having a movable armature and at least one air gap, a magnetizing coil provided on the magnetic guide, the magnetic guide having at least a part formed as an insert of a magnetically hard material, the magnetic guide having an immovable part formed as a cylinder, the movable armature being provided with a cover of the cylinder, the magnetizing coil being located inside the cylinder coaxially to the latter, a rod extending along an axis of the cylinder, located in an inner hollow of the cylinder, and having a part of composed of a electromagnetically soft material, the armature being formed so as to close the magnetic guide with formation of a three dimensional closed structure including the cylinder, the cover, the rod with a possibility of providing a holding force which is equal to a pulling force formed by a winding of the magnetizing coil during a supply of a short-term current pulse to the winding of the magnetizing co

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: To provide a capacitance-type dynamic-quantity sensor capable of reducing a variation in detection sensitivity, free of peeling of an electrode or disconnection thereof, and excellent in reliability, and a manufacturing method therefor. In the capacitance-type dynamic-quantity sensor, a semiconductor substrate where an oscillator is to be formed is processed with a high precision from its front and rear sides to define minute spaces between the oscillator, and flat upper glass substrate and lower glass substrate on each of which an electrode is to be laminated, thereby reducing a variation in detection sensitivity and suppressing peeling of the electrode and disconnection thereof.

Abstract: A power supply method for powering electrical equipment (1) operating on current peaks and connected via at least one capacitive element (5) to a voltage converter (6) connected to a storage battery (3), the voltage converter being current-regulated from a reference current corresponding to a mean current between two peaks.

Abstract: An electromagnetic injection valve is proposed. The electromagnetic valve includes two magnetic coils that are wound in opposite directions and have the same characteristics on the same magnetic circuit, causing the forces of the magnetic coils to cancel each other out at the same excitation current. The two magnetic coils with canceling effect transforms the actual turn-on action of the valve, i.e., the opening of, the valve, into a turn-off action in one of the two coils. A rapid current drop is then determined by an extinction voltage. This makes it possible to achieve rapid force increase times without increasing the supply voltage. The valve can be controlled with a conventional switching output stage or with a current-regulated switching output stage. Reversing a differential current at turn-off also makes it possible to shorten the closing action.

Abstract: A series circuit including a diode for refluxing and a capacitor is connected in parallel to a solenoid coil, and a light-emitting diode is connected in parallel to the capacitor. A negative voltage appearing across the solenoid coil because of an induced electromotive force generated in the solenoid coil can be attenuated and a fall time of current flowing into the solenoid coil can be shortened.

Abstract: By passing electric current through a degaussing coil within a vertical retrace period, a displayed image is prevented from disturbance and yet color blurs on the way of degaussing process are made indiscernible. In the process of discharging charges filled in capacitors C1 and C2 through the degaussing coil, a damped oscillation current by a closed loop of one of the capacitors and the degaussing coil is generated, and then a damped oscillation current of opposite polarity generated by a closed loop of the other capacitor and the degaussing coil is passed, within such a short time as color blurs in the degaussing process cannot be discerned and during the vertical retrace period. With these two damped oscillation currents paired, degaussing operation is fulfilled.

Abstract: A capacitive actuator element, in particular of a fuel injection valve of an internal combustion engine, is charged with different charging times. In order to shorten the charging time, the charging oscillatory circuit is switched over to a freewheeling circuit, and in order to prolong the charging time, switching back from the freewheeling circuit to the charging circuit takes place, it being possible to switch backwards and forwards repeatedly between the freewheeling circuit and charging circuit.

Abstract: An inductive load driver having an inductive load and a bridge circuit connected in parallel with the inductive load, wherein the bridge circuit generates a current to the inductive load that rapidly rises.

Abstract: A method and system for driving a magnetizing fixture. A driving circuit produces in the conductor of a magnetizing fixture a first current whose magnitude increases substantially linearly with time, then produces a substantially constant current in the same direction, then produces a current in the same direction whose magnitude decreases substantially linearly with time, thereby forming a substantially trapezoidal magnetization current waveform having symmetrical sides. The circuit comprises a first energy storage device for supplying electrical energy to the magnetizing fixture, a second energy storage device for receiving electrical energy from the magnetizing fixture, and a commutator interconnecting the first energy storage device, the second energy storage device and the magnetizing fixture for stopping the flow of electrical energy into the magnetizing fixture from the first energy storage device and starting the flow of energy from the magnetizing fixture into the second energy storage device.

Abstract: A horn activation system, which activates a switch for driving a horn, the horn activation system includes a discriminating device that discriminates between the forces being applied to the switch. The discrimination device connects the switch to a power supply for activating the horn when the force being applied to the switch is applied for a time period greater than a predetermined value.

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.