Abstract: The invention provides a control circuit arrangement for solenoid valves, which has a timer adapted to supply the solenoid valve with a higher attraction current during an adjustable time starting with the beginning of a switching signal for the solenoid valve. After the time interval a low hold current flows until the end of the switching signal. For this purpose there is a semiconductor switch adapted to switch the flow of current through the solenoid valve. A logic gate arrangement is connected with an input of the switch and the gate arrangement is supplied with the output signal of the timer arranged to be triggered by the switching signal and the output signal of an oscillation generator. This circuit arrangement makes is possible to reduce a higher attraction current to a lower hold current in a simple and cheap manner, there only being a small overall size and as significant advantages it is possible for the arrangement to be converted for complementary logic.

Abstract: A solenoid control circuit provides energy to selected solenoids to control actuation of a control valve of a fuel injector and, hence, the timing and duration of fuel delivered to each cylinder of an internal combustion engine. The current provided to each solenoid is also controlled to provide a three tier current waveform having a pull-in current level, a hold-in current level, and an intermediate current level. Energizing the solenoid at the pull-in current level starts movement of the control valve. After the control valve starts to move, the current level is reduced to the intermediate level, which is less than the pull-in current level, but great enough to continue movement of the control valve. Further reduction of the current level to the hold-in level, which is less than either of the other current levels but sufficient to hold the control valve at the moved position. The solenoid is then de-energized and the control valve returned to its initial position to stop the flow of fuel to the engine.

Abstract: A comparator comprising two differential input stages (Q1 to Q4 and Q5 to Q8) which are connected in parallel and fed by a common constant circuit source (Q.sub.B) whose current is passed either to both or only to the one or only to the other differential input stage, depending on whether the common-mode input voltage of the comparator is within, above or below a voltage range that is between the voltage values of the two poles (VC, VE) of a supply voltage source (B) of the comparator, and comprising a common current mirror circuit (Q9, Q10) which is associated with the outputs of both differential input stages and from which the comparator output signal is derived. At least one (Q1 to Q4) of the two differential input stages operates in common-base connection, with this differential input stage (Q1 and Q4) receiving its supply current from the common-mode input voltage source.

Abstract: A driver circuit for first and second coils includes first and second selector switches coupled in series between first terminals of the coils and a first common junction, first and second diodes coupled in series between second terminals of the first and second coils, respectively, and a second common junction and a source of first potential coupled to the first common junction. A modulation switch is coupled between the second common junction and a source of second potential. The selector switches and modulation switches are operated to cause currents of controlled magnitude to flow through the coils. The circuit has improved fault immunity whereby at least one coil can be energized even when another coil has been subjected to a chassis ground fault.

Abstract: The invention relates to solid-state circuitry, including a freewheeling circuit, for controlling the operation of an electromagnetically actuated fuel intake or exhaust valve of an internal combustion engine by alternatingly energizing, by way of a current switching element, the coil of the electromagnet at a high level of current for attracting the armature of the electromagnet into engagement with the stator, thus driving the valve into its open or closed position, and maintaining, by way of a transistor, lower level current pulses in the coil sufficient to maintain the engagement.

Abstract: A piloting circuit for inductive loads, particularly for operating the electro-injectors of a diesel engine, comprises an input for connection to a low tension supply, a storage coil for storing energy delivered by the supply, and electronic switching devices for controlling the connection between the input, the storage coil and each of the loads in a predetermined manner to achieve a rapid transfer of current each of the loads selectively a capacitor situated in parallel with the branch circuits containing the loads and connected to the coil and the electronic switching devices, and an electronic control unit. The electronic control unit pilots the electronic switching devices according to a first operative mode in which, to transfer current to one of the loads, the switching devices cause in succession, after the connection the storage coil to the supply, the connection of the storage coil to the capacitor so as to form a resonant circuit, and then the discharge of the resonant circuit into the load.

Abstract: In a fuel control apparatus for an n-cycle engine, when a cylinder discriminating means detects a value obtained by counting turning angle position signals is out a predetermined range, or when a detecting means detects that data of cylinder do not have values according to a predetermined order, a fuel-injection control means performs simultaneous injection of fuel to all cylinders, and thereafter the fuel injection is prohibited until the cylinder discriminating means detects a specified cylinder among the six cylinders.

Abstract: A switching circuit is suggested for controlling the current through an electrical consumer, in particular an electromagnetic consumer (10), whereby a field effect transistor (11) is used as a control and current measuring member being series connected to the consumer. The field effect transistor is brought into the conductive condition with the assistance of a controlling device, such as an operational amplifier which in turn is immediately controlled by switching-on enforcing means when the field effect transistor is short-circuited with respect to a power source. The switching-on enforcing means comprise a capacitor, for example.

Abstract: Inductor coil (13) of a relay (12) used to supply battery power to a power load (11) of a vehicle engine control system (10) is also used to provide a substantially higher than battery voltage (V.sub.Batt) boost voltage (V.sub.Boost) for vehicle control apparatus (20). Microprocessor (21) generates a control signal (V.sub.in) having a 10:1 duty cycle for control of current excitation of the coil (13) during an effective on logic state for the relay (12). During coil current interruptions during the on logic state, energy stored in the inductor (13) is utilized via a rectifier means (26 and 27) to provide the boost voltage. During the on relay state, a movable member (14) of the relay is maintained in its actuated position since current interruptions during the on state are shorter than the relaxation time required for the movable member to assume a nonactuated state.

Abstract: In a method for controlling an injection valve for an internal combustion engine in which the magnet coil of the injection valve is connected to pulsate current by means of a semiconductor switch to an operating voltage in such a way that, during a first time interval, a current which is sufficient to open the injection valve flows and that, following same, there is possibly a second time interval which is dependent on the intended injection time and has a current sufficient for holding the valve open. The first time interval is terminated by disconnection when the current has reached a peak valve which is dependent in accordance with a predetermined function on the operating voltage.

Abstract: An improved dual limit solenoid driver control circuit is disclosed in which solenoid current is sensed and provided as an input to two separate comparators (24, 25). Each comparator receives, during a solenoid pull-in (initial) period (T.sub.1), fixed maximum and minimum reference threshold levels which determine the maximum and minimum current limits (I.sub.max, I.sub.min) for solenoid current during initial pull-in excitation. Subsequently during a hold period T.sub.2 following the pull-in period, each of the comparators receives different maximum and minimum thresholds so as to establish holding solenoid current limits (H.sub.max, H.sub.min). The outputs of the compartors are connected as inputs to a set/reset flip flop (32) whose output controls the operation of a solenoid driver circuit (15). A monostable multivibrator (33) reacts to an initial control pulse (41) to produce a predetermined pull-in time pulse (43) that results in the maximum and minimum pull-in solenoid current limits.

Abstract: A timing arrangement incorporates a timing disk having absolute marks arranged about a circle and serving for the identification of the angular position of the shaft of an internal combustion engine. The marks include a code track havig code marks and absolute marks, each absolute marks being preceded by a code element comprising a number of code marks. Each absolute mark is identified by a code section preceding and consisting of two or more code elements.

Abstract: A fuel injection control method for an internal combustion engine wherein synchronous fuel injection is effected in synchronism with control pulses generated at predetermined crank angle positions of the engine corresponding to suction strokes of respective engine cylinders to supply the engine with a quantity of fuel required for operating conditions of the engine, and when the engine is operating in a predetermined acceleration condition, asynchronous fuel injection is effected independently of the above control pulses to supply the engine with an additional quantity of fuel. The quantity of fuel to be supplied by the synchronous fuel injection is decreased by a predetermined amount immediately after the asynchronous fuel injection is effected. The predetermined amount of fuel corresponds to the quantity of fuel to be supplied by the asynchronous fuel injection.

Abstract: A low voltage supply control system provides on command a voltage doubling of the supply voltage to the fuel injector coils of a fuel injection system. The command signal is responsive to the magnitude of the battery voltage falling below a predetermined level at any time during the operation of the fuel injection systems be it on cold starting or during a component failure in the power generating system of the vehicle during operation. The advantage of this system is that the impedance of the fuel injector coils is typically many times higher than that of coils used without the low voltage supply control system. Overall the cost advantages of the low voltage supply control system are very attractive.

Abstract: In a solenoid fuel injection system, an output transistor (16) receives switching signals to control through current therein which is provided to a solenoid fuel injection coil (11) in series with a current sensing resistor (17). A current control circuit (12) provides pulse width modulation control of solenoid current by monitoring the voltage across the sensing resistor. The fault detection circuit provides separate fault signals for short circuits at either the first or second end terminals (E, H) of the solenoid coil. Separate voltage comparators (18, 23) monitor voltages at the first and second end terminals, and separate delay timers (20, 25) effectively gate the comparator outputs to indicate actual detected short circuits. Each of the fault detection signals sets a fault latch (22) which then acts to reduce current through the output transistor and coil. The fault latch is periodically reset.

Abstract: A protective arrangement for an electromagnetic load is disclosed. In this protective arrangement, the load and a control transistor form a series circuit from the battery voltage to ground and a series circuit of a free-wheeling transistor and a free-wheeling diode is connected in parallel with the load. By coupling the base of the free-wheeling transistor to ground, this transistor is made continuously conductive provided that the polarity of the supply voltage is correct, whereas, this free-wheeling transistor blocks if the supply voltage polarity is incorrect. This assures that none of the components is in danger of being destroyed in the event that the polarity of the supply voltage is incorrect.

Abstract: An apparatus for controlling an internal combustion engine having a plurality of cylinders and fuel injectors provided for the respective cylinders. The apparatus includes a digital computer for calculating a value for fuel delivery requirement based upon various engine operating conditions. The digital computer provides a control signal in response to a demand for engine acceleration. A control circuit is coupled between the digital computer and the fuel injectors for generating synchronous fuel injection pulses having a pulse width corresponding to the calculated value to drive the fuel injectors in synchronism with engine rotation. The control circuit generates an asynchronous fuel injection signal to drive the fuel injectors so as to provide an additional supply of fuel to the engine in response to the control signal.

Abstract: In an injector for intermittently injecting liquid fuel by supplying a pulse signal to an actuator and reciprocating an injector valve, a method of controlling the injector valve comprising the steps of temporarily cutting supply of a pulse signal to the actuator to suppress inertia of the injector valve and thereby stabilize opening characteristics of the valve just before full opening of the valve during an opening stroke of the valve, and temporarily supplying the pulse signal after the cutting step of the pulse signal to the actuator to suppress inertia of the injector valve and thereby stabilize closing characteristics of the valve just before full closing of the valve during a closing stroke of the valve.

Abstract: Each of fuel injectors associated with respective cylinders of an internal combustion engine is driven several times for each air-intake with narrow drive pulses during the engine at low temperature is in a starting stage.

Abstract: A control system for at least one fuel injector in an electronic fuel injection system for a heat engine in which the injector has a linear operating time range defined by a minimum opening time (MIT) and a minimum rest time (MIOT). The system includes a first processor for determining a theoretical injector opening time (TJ), and a second processor directing asynchronous opening of the injector with respect to the phase of the engine, subject to the criteria that the minimum opening and rest times are maintained, while the same linear proportion between the opening and closing time of the injector is also maintained, to ensure that the operating time does not exceed this linear range.

Abstract: A method of controlling the timing of fuel injection in an internal combustion engine, wherein the injection timing of each of a plurality of fuel injection valves provided respectively for as many cylinders is determined in response to engine operating conditions. When it is determined that the engine is in a first predetermined operating condition, fuel is injected into a cylinder that corresponds to the present pulse of a control signal upon generation of same. The control signal is generated at a predetermined crank angle before a top dead center of each cylinder at the start of the intake stroke in the cylinder. When the engine is in a second predetermined operating condition, fuel is injected into another cylinder that corresponds to a pulse of the control signal next to the present pulse, upon generation of the present pulse. Preferably, the first and second predetermined operating conditions are determined by the engine rotational speed and/or the engine temperature.

Abstract: An ultrasonic wave type fuel atomizing apparatus for an internal combustion engine provided in an intake passage of the internal combustion engine and atomizing the fuel injected from a fuel injection pump by the ultrasonic wave vibration includes an ultrasonic wave vibrator, an oscillation circuit for generating ultrasonic waves for driving the ultrasonic wave vibrator, and a high voltage generating coil for boosting the output of the oscillation circuit and for applying the driving output to the ultrasonic wave vibrator, and furthermore, a feedback circuit is included to detect a current flowing through the high voltage generating coil and to control an oscillation frequency of the oscillation circuit thereby to make the driving frequency follow the resonance point of the ultrasonic wave vibrator.

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

Abstract: In an apparatus for controlling an electroexpansive actuator, a high voltage is applied to the electroexpansive actuator at a non-load state after an expansion and contraction operation thereupon is completed.

Abstract: A fuel injection timing control method for an internal combustion engine, wherein fuel injection is effected over a fuel injection period determined based on engine operation parameters from predetermined fuel injection beginning relative to a predetermined crank angle position. The predetermined fuel injection beginning is corrected by a correction value obtained by multiplying the determined fuel injection period by a predetermined coefficient, to thereby determined desired fuel injection beginning. Preferably, the predetermined fuel injection beginning is corrected not only by the above correction value but by a second correction value based on the delay time that elapses from the moment fuel is injected until it is actually drawn into the engine cylinder.

Abstract: In a drive circuit for electrostrictive actuators provided to fuel injection valves in an internal combustion engine, the drive circuit is constituted by a capacitor connected to a direct current voltage source; a switching element connected to the capacitor and used for charging; a first inductor connected to the switching element and used for charging; a plurality of piezoelectric elements used as the electrostrictive actuator; a plurality of other switching elements each connected to each of the piezoelectric elements and used for discharging; a plurality of diodes each connected to each of the piezoelectric elements and used for clamping; and a second inductor connected to each of the piezoelectric elements through each of the switching elements and used for discharging; wherein, at the time of charging, all of the piezoelectric elements are simultaneously charged by turning ON the switching element for charging, and at the time of discharging, predetermined piezoelectric elements are sequentially dischar

Abstract: A method and apparatus for driving an electromagnetic device includes two coils which selectively attract and repel a moving body. In order to allow a quick switching of the moving body between being attracted by one coil and the other, the current through the coil which is not holding the moving body in its magnetic field can be made to be a level higher than the current to the coil which is holding the body in its magnetic field. By reducing the current to the coil that is holding the body, the body can be rapidly switched to be within the magnetic field of the other coil. In addition, the currents to the respective coils can be increased before this switching occurs. Structure can also be provided across the coils to quicken the time it takes for the magnetic field to dissipate.

Abstract: A device for driving an electromagnet from a direct current source includes first and second circuits which are coupled in parallel to each other, and in parallel to a direct current source. The first circuit has a first switch, a solenoid coil, and a second switch all in series with one another. The second circuit has a third switch, a storage coil, and a fourth switch all in series with one another. A third circuit is provided which has a diode which is arranged to provide a current path from a junction between the storage coil and the fourth switch, to a junction between the first switch and the solenoid coil. In operation, during solenoid standby, the choke coil is caused to store electromagnetic energy. When the solenoid coil is energized, the switches are operated such that the energy stored in the storage coil is caused to quickly charge into the solenoid coil. The solenoid coil is maintained energized by operating the first switch in a chopper mode.

Abstract: An air-fuel ratio control system for an internal combustion engine having a carburetor with a slow speed circuit, includes a feedback control means by which an air intake side secondary air is supplied to the carburetor, on the downstream side of the throttle valve, in response to a result of detection of air-fuel ratio in terms of the oxygen concentration in the exhaust gas of the engine. Under a predetermined operating condition of the engine, the feedback control of the air-fuel ratio by means of the control of the air intake side secondary air is performed while the supply of the fuel through the slow speed circuit of the fuel supply system is controlled in response to the result of the detection of the air-fuel ratio. In a variation of the system, the supply of the fuel through the slow speed circuit is stopped during the predetermined operating condition of the engine.

Abstract: A solenoid driver control circuit for use with solenoids, the circuit including a current sense unit (12) for providing a current sense signal and a solenoid drive unit (13) for selectively allowing current to flow through the solenoid (11) from a power source (14). The circuit also includes a threshold comparator unit (17) for comparing threshold signals with the current sense signal and for providing an output signal that can control the solenoid drive unit (13), a minimum threshold unit (18) for providing a minimum threshold, a maximum threshold unit (19) for initially providing a maximum threshold until a peak current flow through the solenoid (11) has been established, a first timing unit (21) to periodically provide increased threshold signals for specified durations of time, and a second timing unit (41) for initially providing an increased minimum threshold signal at the outset of a control cycle.

Abstract: An integrated circuit comprising a series pass transistor for sourcing current from the positive side of a battery to an inductive load includes integrated circuitry for providing a direct current conduction path between ground and the inductive load as the series pass transistor is turned off by the battery being disconnected therefrom during normal operation so that the stored inductive energy of the inductive load is dissipated. The integrated circuitry includes a silicon controlled rectifier (SCR) coupled between the output of the integrated circuit and ground as well as a Zener diode coupled between the gate and anode of the SCR.

Abstract: The present invention is directed to a system for driving a solenoid valve for an internal combustion engine in which the period of a solenoid valve holding pulse signal is preset, and even if an output time of an injector ON control signal changes in response to some particular engine operating conditions, the end of the output time of the injector ON control signal and that of a solenoid valve holding pulse signal are rendered completely coincident with each other. Therefore, the solenoid valve can be controlled accurately at a predetermined injector ON time, thus permitting an appropriate fuel injection.

Abstract: An arrangement for rapid switching of an electromagnetic load includes a series arrangement of a switching device with the electromagnetic load, a relief diode arranged in parallel with the electromagnetic load, and a capacitor arranged in parallel to the switching means. Another switching device is arranged parallel to the capacitor and controls the operation of the latter, while an additional switching device is arranged in series with the relief diode and controls the operation of such relief diode. An operating arrangement for controlling the various switching devices issues various control signals at least some of which depend on electric signals derived from the switching arrangement. During the operation of the switching arrangement, the operating arrangement selectively makes the various switching devices conductive and non-conductive in a predetermined sequence to enhance the speed of switching of the electromagnetic load between its two end states.

Abstract: A temperature compensation injector control system as used in an electronic fuel injection system for motor vehicles utilizes the value of the voltage levels across the coil (18) to determine the coil's (18) temperature. A multiplexer (20) responds to the value of the source of power (14) and the voltage drop across the coil (18) created by a small leakage current to generate digital signals to a microprocessor (10) for modifying injector control signals.

Abstract: A method of and apparatus for controlling the energization of an electromagnetic fuel injection valve in response to the production of an injector control pulse in an electronic fuel injection system. The driver circuit operates a current regulating power transistor into saturation until the current through the solenoid coil of the injector valve attains a predetermined peak current value. A comparator circuit deactivates the power transistor to stop the build-up of current through the coil. A switched free-wheeling circuit is enabled, remains activated, and starts conducting when the power transistor is deactivated by the comparator circuit so that some current continues to be supplied to the solenoid coil when the power transistor is off, thereby causing the current through the coil to decay slowly.

Abstract: An electronic control system for a solenoid based actuator for a fuel system of an engine includes a switchable transistor connected in a series circuit with a current sensing resistor and the solenoid of the actuator. A power circuit supplies switching pulses to the transistor through an AND gate. A control circuit supplies a control signal to the power circuit and also a trigger signal to a monostable circuit. The monostable circuit supplies an enable signal to the AND gate. The control circuit receives a feedback signal from the sensing resistor and as long as this lies within prescribed limits the control circuit will supply the control signal and the trigger signal. If the feedback signal lies outside the prescribed limits at least the trigger signal will be halted so that after the time period of the monostable circuit has lapsed the transistor will receive no further switching pulses.

Abstract: Fuel injections are sequentially effected into cylinders of a multicylinder internal combustion engine in predetermined sequence in synchronism with pulses of a predetermined crank angle position signal from engine rotational angle sensing means. If no TDC signal pulse is generated between an immediately preceding pulse and a present pulse of a cylinder-discriminating signal, a simultaneous fuel injections are effected into all the engine cylinders upon generation of the present pulse of the cylinder-discriminating signal. Preferably, the engine rotational angle sensing means is determined to be abnormal when the simultaneous fuel injections have been effected consecutively a predetermined number of times.

Abstract: An injector driver control unit with internal overvoltage protection. The device includes a first overvoltage sense unit (18) and an injector drive inhibit unit (21) for diverting injector drive signals from an injector drive unit (14) and for diverting flyback energy from a flyback control unit (16). The device also includes a second overvoltage sense unit (19) that can control a clamp control unit (22) to thereby activate an energy clamp (23) to control voltage potential across the injector solenoid (12).

Abstract: A circuit for controlling and indicating the operation of an electromagnetic fuel injector is described in which the injector current is regulated to a predetermined value by switching the injector coil current on and off in response to the coil current value relative to the predetermined value. Operation of the injector is sensed by sensing the change in direction in the duty cycle of the switched coil current as the duty cycle varies while the injector armature moves toward and strikes its stop position.

Abstract: A power supply circuit for an electromagnetic actuator includes a first capacitor and a charging circuit for charging the first capacitor from a second capacitor. A unidirectional switch is operable to discharge the first capacitor into the actuator winding. A second unidirectional switch is operable to provide holding current from a low voltage source of supply to maintain the winding energized. A diode provides energy recovery when the actuator is de-energized.

Abstract: A drive circuit for an electromagnetic device including a solenoid includes a transistor in series with the solenoid and a current sensing resistor. A comparator receives a voltage signal depending on the current flow in the solenoid and by way of an "AND" gate renders the transistor conductive when a control signal appears and non conductive when the current flow exceeds a set value. A first monostable circuit modifies a reference voltage applied to the comparator and reduces the set value of the current after a predetermined time so that the solenoid is initially energised at a high current value which is then reduced to a holding value. The circuit includes a second monostable circuit which causes the transistor to be switched on and off when the current has attained the high value and when the current is at its holding value.

Abstract: A fuel injection solenoid driver circuit controllably connects and disconnects a solenoid coil to and from a storage capacitor to effect operation of the coil. Precise control of the timing and duration of coil is necessary to ensure that a proper quantity of fuel is delivered to each cylinder of an internal combustion engine. A means monitors the voltage level of the storage capacitor and periodically delivers a high voltage inductive spike to the capacitor to maintain the capacitor voltage level within prescribed limitations. Further, a means aids in charging the capacitor by discharging the solenoid coil to the capacitor in response to the coil and capacitor being disconnected. Use of the energy stored in the coil to recharge the capacitor increases the power efficiency of the circuit and also results in a fast decay of the solenoid voltage. The fast decay time minimizes variations in solenoid operation timing and duration and precisely controls the quantity of fuel delivered.

Abstract: A fuel injection pump is described wherein a plunger is rotatingly and reciprocally movable in an enclosure to define a compression chamber which is connected to a fuel inlet during an intake stroke of the plunger and to a fuel outlet during a compression stroke thereby to initiate injection of fuel to the outlet. A solenoid valve is responsive to a voltage applied from a voltage source for providing a pressure relief action on the fuel in the compression chamber. A control unit is responsive to the onset of fuel injection to determine a basic timing at which fuel is to be terminated and corrects the basic timing as a function of the source voltage to compensate for a voltage variation thereof which would otherwise affect on the operation of the solenoid valve. The solenoid valve is then energized at the corrected timing.

Abstract: A system and method for synchronizing ignition and fuel injection pulses produced by the interruption of Hall Effect signals by a window-in-vane interrupter in an internal combustion engine ignition distributor.

Abstract: A fuel supply control method for multicylinder internal combustion engines, includes calculating the quantity of fuel being supplied to the engine in response to operating conditions of the engine, and sequentially supplying quantities of fuel corresponding to the calculated values into respective corresponding ones of the cylinders. The fuel quantity is calculated in synchronism with generation of pulses of a timing signal equal in number to the number of the cylinders at predetermined crank angles of the engine per one cycle of the engine.

Abstract: An injector driver fault detect and protection device for use with fuel injection systems that include at least one solenoid (17) for controlling a fuel injection valve, control means for providing a control signal, injector driver means (14) responsive to the control signal for providing a drive signal, and a current control switch (16) being responsive to the drive signal for selectively closing and opening a power line that includes the solenoid (17) to thereby control the fuel injection valve. The device includes a fault detect and protection unit that receives current sense information regarding the flow of current through the solenoid (17), control signals from the control unit (13), and engine rotation data in the form of CAM degrees from a CAM position sense unit (19).

Abstract: A motor vehicle fuel system operable selectively to supply metered quantities of petrol or LPG in its gaseous state to a carburetter induction passage. The LPG system includes a single stage pressure regulator and an injection valve which may be a digital or an analogue valve. The regulator operates to vary the pressure of gaseous LPG with variations in engine loading by referring that pressure across a single diaphragm to the pressure established in the induction passage downstream of the throttle valve by operation of the engine, while maintaining that regulated gas pressure above that subsisting in the induction passage upstream of the throttle valve.

Abstract: A fuel supply control method for multicylinder internal combustion engines, includes calculating the quantity of fuel being supplied to the engine in response to operating conditions of the engine, and sequentially supplying quantities of fuel corresponding to the calculated values into respective corresponding ones of the cylinders. The fuel quantity is calculated in synchronism with generation of pulses of a timing signal equal in number to the number of the cylinders at predetermined crank angles of the engine per one cycle of the engine.

Abstract: Fuel injection apparatus including a power converter for generating a stable, high voltage DC signal for powering the fuel injectors. The power converter is connected to a voltage source such as a vehicle battery. The power converter includes a DC-DC converter and a feedback-stabilized converter control circuit. The converter control circuit adjusts the operation of the DC-DC converter in a direction to counteract changes in output voltage caused by battery voltage variations. The high voltage DC signal is applied to each injector through one or more solid state switches. Since the signal used to power the fuel injectors is substantially constant regardless of normal battery voltage variations, the injector pull-in time is substantially constant. Moreover, the use of a high voltage power signal enables low current injectors to be used. The low injector current results in low power dissipation by the solid state switches which operate the injectors.

Abstract: A method of and arrangement for supplying a maximum quantity of fuel which is supplied to a combustion engine in certain operational conditions independent of rate of airflow and rotational speed is provided with an altitude-correcting signal which depends the maximum amount of fuel to be supplied on the air density of the actual operational altitude of the combustion engine. Through the provision of such an altitude-correction signal, a too rich mixture of fuel and air is prevented.