The Bendix Corporation

Robert S Henrich

Thomas W Hartford

James A Kessler

Alan W Barman

John A Walworth

Circuitry (20) for activating fuel injectors (50) of an internal combustion engine 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).

Boost voltage generator

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).

Switching type driver circuit for fuel injector

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.

Dual coil driver

A method and apparatus for controlling the various functions of an internal combustion engine using a program-controlled microprocessor having a memory preprogrammed with various control laws and associated control schedules receives information concerning one or more engine-operating parameters such as manifold absolute pressure, throttle position, engine coolant temperature, air temperature, engine speed or period and the like. These parameters are sensed and then supplied to input circuits for signal conditioning and conversion into digital words usable by the microprocessor. The microprocessor system computes a digital command word indicative of a computer-commanded engine control operation and output circuitry responds to predetermined computer-generated commands and to the computed digital command words for converting them to corresponding pulse-width control signals for controlling such engine operations as fuel-injection ignition timing, proportional and/or on-off EGR control, or the like. The engine control system further includes an oxygen sensor feedback system for supplying signals indicative of the quantity of oxygen in the exhaust system of the engine back to the microprocessor for control purposes. In particular this disclosure relates to an oxygen sensor condition circuit which generates not only the bilevel output signals indicating the quality of oxygen in the exhaust system, but also generates an oxygen sensor inhibit signal which may be used in a control system to effectively disregard the output of the sensor and to apply fixed or preprogrammed conditions for controlling the air/fuel ratio. Typically the purpose of the inhibit signal is to indicate when the sensor is inoperable because of its operating temperature or its physical condition.

Oxygen sensor signal conditioner

A signal conditioning circuit for the output of a magnetic position sensor is disclosed. The magnetic sensor generates a total output signal that increases as a function of the rotational velocity of the sensor with a spurious noise component that is a relatively constant percentage of the actual signal voltage over the speed range. In a preferred embodiment, the signal conditioning circuit discriminates between the noise component and the signal component by comparing the total signal to a variable threshold only after a positive going zero cross. The variable threshold is generated as a function of the peak amplitude of the total signal. In a second embodiment the signal conditioning circuit includes gain control means which varies the amplitude of the total output signal as a function of its peak to maintain the threshold above the noise component.

Signal conditioning circuit for magnetic sensing means

A method and apparatus for controlling the various functions of an internal combustion engine using a program controlled microprocessor having a memory preprogrammed with various control laws and associated control schedules receives information concerning one or more engine-operating parameters such as manifold absolute pressure, throttle position, engine coolant temperature, air temperature, engine speed or period and the like. These parameters are measured and their value or status is supplied to input circuits for signal conditioning and conversion into digital words usable by the microprocessor. The microprocessor system computes a digital word indicative of a particular computer-commanded engine control operation and output circuitry responds to predetermined computer-generated commands and to the computed digital words for converting it into a corresponding pulse-width control signal for controlling such engine operations as fuel-injection, ignition timing, proportional and/or on-off EGR control, and the like. The engine control system further includes 'limp home' circuitry for enabling the engine to function for a predetermined time even after the microprocessor fails to enable the vehicle to get to a place of repair or the like.

Ignition limp home circuit for electronic engine control systems

A method and apparatus for controlling the various functions of an internal combustion engine using a program-controlled microprocessor system having a memory preprogrammed with various control laws and associated control schedules receives information concerning one or more engine-operating parameters such as manifold pressure, throttle position, engine coolant temperature, air temperature, engine speed or period, and the like. These parameters are sensed and then supplied to input circuits for signal conditioning and conversion into digital words usable by the microprocessor system. The microprocessor system computes a digital command word indicative of a computer-commanded engine control operation and output circuitry responds to predetermined computer-generated commands and to the computed digital command word for converting them to corresponding pulse-width control signals for controlling such engine operations as fuel-injection, ignition timing, proportional and/or on-off EGR control, and the like.

Oxygen sensor qualifier

An electronic ignition timing system for an internal combustion engine is disclosed. The system integrates for a first time interval a time dependent charge signal indicative of the ignition advance as a function of engine speed, then dissipates the integrated signal as a function of engine load to a predetermined value to generate an ignition timing signal which is a function of both engine speed and engine load. The time dependent charge signal varies from one value to another at predetermined time intervals to closely approximate the nonlinear ignition advance requirements of the engine as a function of engine speed.

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Farmington Hills, MI, United States of America

Robert S Henrich