Abstract: Sync pulses are developed in timed relation to the occurrence of an ignition event in a specified cylinder of an engine employing a concurrent discharge ignition system. Ignition voltages for compression and exhaust cylinders are distinguished on the basis of the voltage magnitudes thereof.

Abstract: This invention relates to a fuel injection timing control unit for an electronic controlled fuel injection apparatus mounted on an internal combustion engine. The fuel injection timing of a fuel injection valve is first calculated and subsequently adjusted or modified due to an amount of throttle opening or an engine speed, thereby improving the engine response when a rapid acceleration of a vehicle is necessary.

Abstract: The invention is directed to a current regulator for an electromagnetic load used in conjunction with an internal combustion engine. The regulator produces positive and/or negative currents flowing through an electromagnetic load. In this arrangement, the two potentials present at a precision resistor that is connected in series with the load are adjusted to freely selectable values. To obtain both positive and negative currents, the current defined by the voltage drop occurring along the precision resistor is provided by a bridge circuit made up of four current-controlling arrangements. Allowance can be made for particular operating conditions of the current regulator simply by presetting desired values.

Abstract: An engine control system for controlling a fuel injector in response to a desired fuel flow magnitude provides selective switching between firing a fuel injector once and more than once during each engine cycle. At low fuel flow rates, fuel injector operation can be maintained in a linear portion of the fuel injector characteristics by using only one fuel injector firing during an engine cycle.

Abstract: Fuel injection modes including an independent injection mode, group injection mode and simultaneous injection mode are changed over in accordance with an engine operating condition, for example, a load condition. The independent injection mode is selected when the engine is operating in a low load condition, and the fuel injection timing for each cylinder is controlled independently. When the low load condition of the engine changes to an intermediate load condition, the group injection mode is selected and the fuel injection timing is controlled for each group of cylinders formed by grouping the cylinders into at least two groups. The simultaneous injection mode is selected when the intermediate load condition changes to a high load condition, and the fuel injection timing for all the cylinders is controlled to be simultaneous.

Abstract: There is disclosed an internal combustion engine in which synchronous fuel injection is conducted at every predetermined crank angle and an asynchronous fuel injection is conducted regardless of the crank angle. The engine is provided with an electronical control circuit which computes a quantity of fuel to be injected in each synchronous fuel injection on the basis of a load applied to the engine and an engine speed. A variance of intake pressure in said engine is computed. The computed variance is compared with a reference level which is determined to be greater as the intake pressure becomes higher. In the case of detection of the variance of the intake pressure being greater than said reference level, said quantity of fuel to be injected is increased.

Abstract: For controlling a pulse-operated electromagnetic valve, an energization voltage is applied to the actuating coil of the valve in response to a leading edge of the pulse to initiate an energization current. When the current reaches a predetermined peak value the voltage is decoupled from the coil to allow a circulating current to flow through a first path to decrease it at a higher rate. The circulating current is switched to a second path when it reaches a medium current value to decrease it at a lower rate. When the decreasing circulating current reaches a lower holding current value which is necessary to hold the valve operated, the voltage is coupled again to the coil to reinitiate the energization current, and when it reaches a higher holding current value lower than the medium current value the voltage is decoupled to reinitiate the circulating current.

Abstract: An extended range throttle body fuel injection system wherein overlapping or near-overlapping fuel quantity pulse width signals are compensated to maintain the operation of the injectors in a near linear operating mode. The system is capable of being implemented in software for controlling microprocessors in a microprocessor based system or in hardware logic for operation in a hardware system.

Abstract: A solenoid driver circuit has reduced power consumption by providing relatively fast current decay to a sustaining low current after an initial peak activation current. Subsequent sustaining current peak applications have a smaller magnitude than the initial peak current and are followed by slower decays for a predetermined length of time to a lower current level. Two transistors and a Zener diode are operatively connected to the solenoid and controlled by a logic circuit to apply the desired current to the solenoid. The two transistors are turned on and off using logic flip-flops to sense voltage comparisons with the initial peak current voltage, the sustaining peak current, and the sustaining low current. A logic signal is generated as a function of the predetermined length of time, and an output signal is coupled to the bases of the two transistors to control their on/off states.

Abstract: In an electronic fuel injecting method for an internal combustion engine, wherein fuel injection timings for every groups are controlled in accordance with reference signals variable in the proximity of intake top dead center of a predetermined cylinder and the angle signals variable at every predetermined rotary angles, during a low rotational speed operation of the engine, all of the cylinders perform injections simultaneously in accordance with the angle signals according to the necessity, during a medium rotational speed operation of the engine, group injections with the cylinders being discriminated by the reference signal are performed in accordance with the reference signals and the angle signals, and, during a high rotational speed operation of the engine, group injections with the cylinders being not discriminated by the reference signal are performed in accordance with the angle signals according to the necessity.

Abstract: A so-called current-regulated end stage for electromagnetic consumers such as magnetic valves or electromagnetic final control elements is provided, in which a field effect transistor takes over the functions of the switch and of the current measuring resistor. When the field effect transistor is conductive, the voltage over a capacitor is made to follow the current flowing through the consumer, and when the field effect transistor is blocked, the flow of current through the free-running circuit is simulated via the capacitor discharge. Both a singlefold and a multiple realization are disclosed, the latter using multiple examples of an RC member and a threshold switch.

Abstract: A current regulator is proposed for use in an electronically controlled, continuously operating gasoline injection system, with the aid of which a control element can be supplied with different current values depending upon the operating states of the engine. In addition to a current regulating phase during active operation, it is possible with the proposed current regulator to reverse the direction of current flow in the control element for the sake of blocking the supply of fuel during overrunning. Towards this end a circuit apparatus links signals relating to rpm, throttle valve position and temperature. Furthermore two safety circuit arrangements are proposed for the current regulator, so that in case of a failure of important components there is no impairment of safety, and emergency operation is assured.

Abstract: A single spot fuel injector is energized only twice per revolution of the crankshaft of the engine so that under given operating conditions the injections coincide with the TDC and BDC positions of a piston of a selected cylinder of the engine. Under higher engine speed operation, the injection timing is advanced to improve the fuel distribution to the cylinders. When the engine operates at an engine speed below a predetermined level it is possible for the injector to be energized three times per revolution of the crankshaft.

Abstract: A switching type control unit (20) for activating fuel injectors (50) of an internal combustion engine. The control unit (20) including a plurality of switching circuits (60) for turning on and off associated hybrid power circuits (80). The hybrid power circuits (80) communicate the increased level of voltage generated by a single boost voltage generator (70) to particular injectors (50).

Abstract: A control device is proposed for an electromagnetic engine valve or an electromagnetic final control element. The control device operates with closed-loop current control, and the maximum current is ascertained via a measuring resistor located in series with a switching transistor, while the free-running circuit is controlled in accordance with time. This control in accordance with time is effected via a comparator having dynamic positive feedback and acting as a comparison stage. The free-running control circuit includes a diode for protective purposes switched parallel to a transistor.

Abstract: A fuel injection control method for successively injecting fuel into a plurality of cylinders of an internal combustion engine in predetermined sequence in synchronism with pulses from top-dead-center detecting means which are successively generated immediately after generation of each pulse from cylinder-discriminating means. The method is adapted to perform a fail safe function in the event of occurrence of an abnormality in the cylinder-discriminating means. The number of pulses is counted which are successively generated from the top-dead-center detecting means immediately after generation of each pulse from the cylinder-discriminating means. If no further pulse from the cylinder-discriminating means is detected until the count of pulses from the top-dead-center detecting means reaches a number equal to the sum of the number of the engine cylinders and while the rotational speed of the engine is higher than a predetermined value, the cylinder-discriminating means is regarded as abnormal.

Abstract: In a single point electronic fuel injection system for injecting fuel at the upstream side of a throttle valve in synchronism with the sucking stroke of engine, upon low-speed driving, particularly upon idling drive, the total amounts of fuel necessary for a previous sucking stroke and the following sucking stroke are injected at a time in the previous sucking stroke and no fuel is injected in the following sucking stroke.

Abstract: Disclosed is a fuel injection valve drive circuit for use in an internal combustion engine wherein the excitation current supplied to the fuel injection valve winding is controlled on a feedback basis so as to maintain the specified value during the period of the valve opening command signal. A control signal based on the difference between the signal representing the excitation current and the reference signal is produced, and the excitation current is controlled by the pulse width modulation signal which is produced based on the magnitude of the control signal.

Abstract: A circuit for controlling the energy supplied to electromagnetic injector valves in an electronically controlled fuel injection system is disclosed herein. The disclosed circuitry limits the voltage available to the injector valves to a selected maximum level slightly below the minimum voltage normally obtainable from a vehicle battery recharging system and further limits the maximum current flow through the electromagnetic coil of each open injector valve to a preselected valve. The preselected current value may be changed during operation to minimize energy stored in the magnetic field of the electromagnetic coils.

Abstract: A fuel supply control system for an engine includes a controller and a fuel supply line. In one embodiment, at least two parallel connected control valves are arranged in the line and are changed between open and closed states when energized by a drive signal. A sensor is provided for detecting an engine operating condition. A generator is provided for producing a random designation signal indicating any one of the different control valves. The controller produces a pulse train as the drive signal for the control valves in response to the output signal of the sensor so that the duty cycle of the pulse train varies with the engine operating condition. The controller distributes each pulse of the drive signal to any one of the control valves designated by the random designation signal of the generator to open the designated control valve so that any one of the control valves is opened in a random sequence. In a second embodiment, the number of the control valves may be one.

Abstract: A combined ignition control and injection valve operating circuit has an inductor connected in (series or) parallel with the ignition coil so that it carries current whenever an output transistor of an ignition control circuit is on.A thyristor connects the inductor to an energy storage capacitor and turns on each time the transistor turns off to create an ignition spark. The capacitor is thus charged up and the stored energy is discharged through a triac into an injection valve solenoid to speed up current growth in the latter on each energization thereof.

Abstract: An injector driving circuit includes a first diode forwardly coupled between one end of a solenoid coil and a positive power supply terminal, a capacitor with one end grounded, a second diode forwardly coupled between the other end of the coil and the capacitor with respect to the positive power supply terminal, a switching transistor coupled between the other end of the coil and the ground and connected to be turned on in response to a driving input signal, a current detecting circuit for detecting current flowing through the coil and producing an output signal when detecting that the coil current has reached a predetermined value, and a switching circuit coupled between the one end of the coil and the other end of the capacitor and connected to be closed and opened in response to the driving input signal and the output signal of the current detecting circuit, respectively.

Abstract: A quadrature trigger system for a sequential fuel injection system utilizes a single lobe timing cam connected to the camshaft of a four cylinder internal combustion engine as illustrated in FIG. 2. Positioned in a sensing relationship to the cam are two proximity sensors which generate bilevel electrical signals having a fifty percent duty cycle and which are spaced ninety electrical degrees apart. These electrical signals are decoded in a logic network to direct fuel injection pulses from either of two pulse generators to the proper sequenced fuel injector.

Abstract: An apparatus for generating signals to control the firing of spark plugs or the operation of a fuel injection distributor for an internal combustion engine having multiple cylinders utilizes sensors that scan markings on the crankshaft and camshaft and an evaluating circuit to develop such control signals.

Abstract: An injector drive circuit in which the injector is opened in response to a pulse signal with a time width which determines the quantity of the fuel to be supplied to the engine. To the injector, a circuit for supplying a peak current at the time of fuel injection and a field effect transistor for supplying a holding current after supply of the peak current are connected in parallel. In response to the control signal from a fuel injection amount control circuit, the peak current is supplied to the injector, and upon detection that a predetermined peak current has been supplied to the injector, the peak current is stopped. Thereafter, by controlling the gate of the field effect transistor, the holding current is supplied to the injector through the field effect transistor, until the control signal is stopped.

Abstract: An integrated circuit is operative to produce an output current to a load and for switching the output current when a predetermined peak magnitude of load current is reached to a lower predetermined constant value. The circuit includes an internal power stage rendered conductive for producing maximum load current through the external load which is connected in series therewith in response to an internally generated reference current. The power stage comprises a multi-emitter power transistor with each emitter coupled to a respective emitter ballast resistor such that the load current through one of the resistors may be sensed and compared to the reference current to cause the magnitude of this reference current to be switched from a maximum value to a minimum value when the sensed current is representative of the peak magnitude value of current to thereby reduce the load current until the magnitude thereof is representative of the lower level of reference current.

Abstract: A system for energizing a fuel injector, of a fuel injected engine having a metering chamber and a two coil solenoid operatively situated thereto for permitting a controlled quantity of fuel to flow therein. The system includes a pulse generator for generating a plurality of timing and fuel metering pulse width signals in synchronism with the combustion process within a cylinder of the engine, a voltage boost circuit responsive to timing and metering pulses and means for transferring, in seriatim energy from the boost circuit to a first low inductance pull-in coil and for energizing a second high inductance hold coil.

Abstract: An apparatus is proposed for driving electromagnetic devices, in particular electromagnetic injection valves in internal combustion engines. The apparatus includes a signal source for actuating pulses and is characterized in that at least one timing circuit is provided for advanced magnetization, preferably dependent on operating characteristics, of the electromagnetic device. The apparatus achieves the most linear possible relationship between the duration of the actuating pulse and, for example, the opening time of the injection valve. In this manner, the fuel quantity to be supplied to the internal combustion engine can be more precisely dosed and the operational behavior of the engine can be made optimal.

Abstract: An injector drive circuit for driving an injector having a valve opened and closed according to a pulse signal with the pulse duration thereof corresponding to the quantity of fuel supplied to the engine. The injector drive circuit comprises a current supply power transistor connected to an injector coil. According to an electric pulse signal from a fuel injection control circuit, a first current control section causes base current to flow into the power transistor for causing a peak current through the injector coil. When a predetermined peak current is detected, the base current supplied by the first current control section is cut off. From this instant till the disappearence of the electric pulse signal, a second current control section, which supplies base current to the power transistor only when the current supplied from the power transistor to the injector coil becomes lower than a working current level, supplies in effect the working current through the power transistor to the injector.

Abstract: A fuel injection valve drive system is disclosed for use in an internal combustion engine including at least one solenoid operated fuel injection valve. The system comprises a first pulse generator for providing, in synchronism with rotation of the engine, a first pulse signal having a constant pulse width, a second pulse generator for providing a second pulse signal of pulse width dependent upon the amount of air introduced to the engine, first switch means responsive to a first pulse signal for allowing small current to flow through the solenoid coil of the fuel injection valve so as not to open the fuel injection valve, and second switch means responsive to a second pulse signal for allowing large current to flow through the solenoid coil so as to open the fuel injection valve. Means are provided for causing the second pulse generator to generate a second pulse signal a time after the first pulse generator generates a first pulse signal.

Abstract: A device is proposed for controlling the current through switching devices which function inductively, in particular magnetic valves in the fuel metering system of an internal combustion engine, with which it is possible to control the current during an attracting and maintenance phase. A primary characteristic is a bracketed and controllable constant-voltage source parallel to the base-emitter path of a switching transistor and of a measuring resistor. Furthermore, a threshold switch connected with its positive input to the measuring resistor is coupled with positive feedback, and the negative input of this threshold switch is connected to a voltage divider controllable in accordance with the input signal.

Abstract: An apparatus is proposed for controlling the electric current through inductive consumers, in particular through a fuel metering valve in internal combustion engines, this apparatus representing a two-point closed-loop controller and functioning with a single threshold switch for an upper and a lower threshold. The apparatus includes one current-measuring resistor each in the freerunning circuit and in the main current circuit, both measuring resistors being members of a voltage divider between the two supply voltage lines and whose middle junction is carried to the threshold switch. By means of a resistor-diode network in combination with the threshold switch, a correction can be made in the individual switching thresholds in accordance with supply voltage.

Abstract: A driver circuit, having boost and hold modes of operation, for a solenoid having a high and a low impedance coil wherein the coils are so situated such that their respective magnetic fields are additive and wherein the driver circuit is responsive to input metering pulse width signals and includes means for modifying the duration of each pulse width signal to generate a boost pulse signal to excite the low impedance coil in correspondence with the variations in the battery voltage. The driver circuit further includes means for permitting the current flowing through the low impedance coil into flow into a high impedance coil and means for regulating the value of current flowing therethrough at a determinable value. The driver circuit further includes means for reducing the current droop occurring upon the transition from the boost mode of operation to the hold mode of operation.

Abstract: An apparatus for controlling the current through an electromagnetic injection valve of an internal combustion engine during its pickup and holding phases by opening and closing a first switch connecting the valve to a voltage source. The first switch is initially closed by a valve timing circuit to initiate pickup of the valve. A first current-sensing resistor connected in series with the first switch produces a signal to open the first switch when the valve current attains an upper threshold value which assures valve pickup, and to close a second switch connected in series with a second current-sensing resistor across the valve. When the valve current drops to a lower threshold value greater than the valve drop-out current, the second current-sensing resistor produces a signal to reclose the first switch and open the second switch for a predetermined time, after which the first switch is again opened and the second switch closed.

Abstract: An apparatus is proposed for controlling the de-excitation time of electromagnetic devices, in particular electromagnetic injection valves in internal combustion engines, wherein a switch (or an actuation circuit in general) is disposed in series with the device, characterized in that a circuit arrangement with a controllable output potential is disposed in series or in parallel with the electromagnetic device. It is the purpose of the apparatus to linearize the current decrease through the electromagnetic device after the end of the actuation pulse and preferably to simultaneously control its rate of decrease. As a result, control of the de-excitation time of the particular electromagnetic device is attained. In terms of function, the circuit arrangement represents a controllable Zener diode.

Abstract: A driver circuit for electronically actuating in a predetermined sequence, a plurality of solenoids (54). The driver circuit includes a single boost circuit (22) having an inductor (118) for receiving energy from a power supply and a capacitor (110) for storing a portion of this electrical energy prior to activation of a particular solenoid. The driver circuit further includes circuitry associated with each solenoid (40, 80, 82, 84) for energizing the solenoid by causing the capacitor (110) to discharge therethrough and to regenerate the stored voltage potential prior to the time for energizing another solenoid, The drive circuit further includes a current regular and mode control (70, 150, 170) to control the magnitude of current flowing through each solenoid.

Abstract: A solenoid drive circuit includes two output transistors in parallel paths of relatively high and low resistance respectively. The low resistance path transistor is controlled by a voltage comparator arranged to compare the voltage across a common current sensing resistor with a reference voltage. When the input to the circuit is low, the high resistance path transistor is biased on, but where the current is below a set level, only the low resistance path transistor conducts. Only when the comparator changes state as the solenoid current exceeds its set level does switching off of the low resistance path transistor permit the other transistor to turn on. A delay circuit is included which operates to prevent the low resistance path transistor turning on if there is a short circuit across the solenoid.

Abstract: In a closed loop air-fuel mixture control system for carburetor-equipped internal combustion engines, an exhaust gas sensor provides a feedback signal to a control unit where the signal is modified to meet the control characteristics of the closed loop. The modified feedback signal is converted into digital pulses whose width varies with the amplitude of the feedback signal. Additional air is supplied to the engine through an air bleed in accordance with the magnitude of the analog feedback signal to provide a coarse control of air-fuel ratio and in response to the digital pulses to provide a fine control of the ratio. The mixture is controlled in a wide range of ratios to eliminate the need for calibration which would be required for fitting the closed loop system to the time-varying characteristics of individual carburetors.

Abstract: An installation for the operation of electromagnetic loads, especially solenoid valves, in fuel supply systems in internal combustion engines, wherein a measuring resistor as well as a switch are connected in series with the load and the entire arrangement is connected to the two supply voltage terminals. The installation comprises two comparators connected in parallel with the measuring resistor, at least one resistor being connected in front of these comparators, and controllable current source arranged between the junction of the threshold switch and the resistor in the proximity of the load, as well as a supply voltage terminal. The supply voltage of one of the comparators is made dependent on the voltage in the freewheel circuit, to maintain at least one of the comparators in the operating position even during freewheeling operation.

Abstract: A solenoid control circuit includes a first switching element which connects one side of the solenoid load to earth via a current sensing resistor. The other side of the solenoid load is connected by a second switching element to a supply rail. This second switching element is biased to conduct but can be turned off by either of two comparators which are connected to compare the voltage across the current sensing resistor with two different reference voltages. Each comparator has hysteresis and the circuit operates so that one comparator operates to switch off the second switching element when a predetermined current level is reached and the other comparator operates to switch the second switching elements on and off at lower current levels between said predetermined current level and the lower threshold level of the first comparator.

Abstract: A method for extending the range of operation of an electromagnetic fuel injector for an internal combustion engine employs a technique for reducing the time required for the injector to open while at the same time allowing the injector to maintain a minimum closing time. Prior art techniques have utilized a regulated voltage supply to determine the precise voltage applied to the inductive element of the injector to cause it to open. The present invention does not regulate the applied voltage, but instead the invention allows an unregulated battery or other DC supply voltage to be applied to the inductive element to cause the injector to open as rapidly as possible. The current in the injector is sensed to allow a reduction in the applied voltage when a predetermined maximum current occurs in the inductive element. The voltage reduction permits a holding current to be established in the inductive element to maintain the injector open.

Abstract: A method and apparatus for reliably switching electromagnetic control units, especially solenoid valves for blocking the idling fuel mixture in carburetor units of internal combustion engines during, for example, motor vehicle coasting. It is proposed to deenergize the solenoid valve at the beginning of the blocking operation for a time period ensuring a reliable valve release, initiating a current flow which preferably allows the solenoid valve to be at the brink of opening, and, at the desired instant of opening applying an overvoltage to the solenoid valve in a standby position, wherein the valve, though it has not as yet opened, requires merely a small additional pulse to open.

Abstract: An actuation timing apparatus is disclosed for providing triggering and steering control signals to an electronic control unit regulating a plurality of solenoid fuel injectors of a sequential injection system. The apparatus includes a rotatable member which is rotated in synchronism with the engine at the speed of its camshaft. The rotatable member has a plurality of spaced sensible elements geometrically disposed thereon and divided into groups identifying individual cylinders. Each group has at least one sensible element which defines a reference element having a recognizable characteristic distinguishing it from the other sensible elements in the group. A single sensor senses the spaced sensible elements of each group as they rotate past a fixed sensing location and generates corresponding electrical pulses to a pulse processing circuit. The pulse processing circuit decodes each group of pulses to provide the identity of the injector to be next actuated.

Abstract: Electric control apparatus for providing an enabling control signal and a steering control signal to control the electronic fuel injectors of a sequential fuel injection system of an internal combustion engine is disclosed. The apparatus includes a rotatable disc which rotates in synchronism with the engine. The disc has a plurality of spaced sensible elements contained thereon, one of the sensible elements defining a reference element which has a recognizable characteristic distinguishing it from the other sensible elements. The distance between the reference element and an adjacent element defines a predetermined distance different than the distance between any two adjacent nonreference elements. A single sensor senses the spaced sensible elements and provides corresponding electrical pulses. A pulse processing circuit electrically connected to the output of the sensor processes the pulses.

Abstract: A compensated dual injector driver circuit for controlling the current to either of a pair of electromagnetic solenoid fuel injectors is disclosed. The driver circuit includes a pair of analog bilateral switches operably connected to the control terminals of two driver transistors whose power terminals are coupled serially with the coils of the injector solenoids. A driver amplifier generating a current control signal for the driver transistors is connected to a common input of the two switches. Either of the switches is selected for closure by a logical input from a select line thereby choosing the individual injector to be energized. The driver amplifier in response to the leading edge of a control pulse regulates the conductance of the selected transistor with the current control signal to initially draw current through the injector coil until it reaches a peak value. At the time the peak current is attained, the driver amplifier then switches the control current to a holding value.

Abstract: An inductive load driver circuit comprising first and second switch means and high and low impedance load current decay means. For the duration of a load actuation signal the first switch means are responsive to the magnitude of the load current to complete and interrupt a first current path to the load to cycle the load current between first and second levels. The second switch means are enabled for the duration of the load actuation signal to complete a second current path to the load when the first switch means interrupts the first current path. When completed the second current path comprises the low impedance decay means allowing the load current to decay slowly from the first current level to the second level to provide during such slow decay a load current sufficient to maintain actuation of the inductive load.

Abstract: A system for energizing an inductive load includes a voltage regulator for providing a constant voltage across the load until the current builds up to a particular value, and a current regulator which then takes over to provide a constant holding current at a lower value. The voltage regulator may include a closed loop for holding the voltage across the inductive load constant or may respond to a regulated voltage value to control a power stage for providing a constant voltage. The voltage across a sensing resistor in the power stage controls the crossover from the voltage regulation mode, to the current regulation mode and the current regulator automatically resets the reference to control the power stage to provide a constant current of a lower value through the load. The system can be used to supply current to coils of injector valves in a fuel injection system, and may include two power stages for supplying current to two banks of coils.

Abstract: A fuel injection system employing digital logic to generate injection command pulses of a time duration calculated to provide a precise quantity of fuel to meet presently existing, varying engine requirements is disclosed herein. The system employs a first or injector selection circuit operative to select an injector or injector group for injection and a second or adaptive delay circuit to generate an injection command. The circuits are electronically intercoupled to provide for substantially simultaneous application of the selection pulse and injection pulse to the proper injector group and to eliminate the need for a mechanical distributor arrangement to select the proper injector group. The time duration or delay signal is generated by a function generator producing an output as a known function of time with injection occurring during the time it takes for the output to reach a pre-determined, selected, threshold value.

Abstract: A device for controlling an electromechanical transducer such as a proportional electromagnetic valve, in which a pulse signal having a constant period shorter sufficiently than the minimum response time required for the displacement of the plunger of the proportional electromagnetic valve over its predetermined full stroke is applied to the electromagnetic coil of the proportional electromagnetic valve to superpose a very small vibratory stroke component on the stroke of the plunger, and the duty cycle of the pulse signal applied to the electromagnetic coil is varied so as to urge the plunger in directly proportional relation to the variation of the duty cycle without substantially giving rise to mechanical hysteresis in the stroke of the plunger.