Chrysler Corporation

LaVerne Andrew Caron

Frederick William Crall

Lawrence William Tomczak

Walter Joseph Campau

A novel electronic control circuit which may be used in different types of electronic engine control systems is disclosed. Illustrative usage in various types of electronic spark timing control systems contemplates 4, 6, and 8 cylinder engine configurations as well as single or multiple pick-ups. The circuit is intended for fabrication as an integrated circuit device to provide a low-cost unit which is advantageous in mass production usage.

Electronic circuit for use in a variety of engine control systems

A circuit for multiplying two variables wherein one variable is represented by the pulse width of the pulses of a variable pulse width, constant frequency rectangular waveform signal and the second variable is represented by the level of a variable amplitude signal. When the value of the first variable is zero, pulses of the rectangular waveform signal have a definite non-zero pulse width. An oscillator cicuit produces a reference rectangular waveform signal having a frequency equal to that of the first rectangular waveform signal. From these two rectangular waveform signals there is developed a third rectangular waveform signal having the same frequency but having the width of its pulses directly proportional to the value of the first variable so that the pulses are of zero width when the first variable is zero. A fourth rectangular waveform signal is developed from the third rectangular waveform signal and from said variable amplitude signal such that the pulse amplitude of said fourth rectangular waveform signal is proportional to the value of the second variable and the pulse width is directly proportional to the value of the first variable. The fourth rectangular waveform signal is passed through a low pass filter to produce a DC signal whose magnitude is directly proportional to the area of the output pulses of the fourth rectangular waveform signal and hence to the product of the two variables.

Circuit for multiplying two variables

There is disclosed circuitry for developing ramp type signals such as sawtooth waveforms, triangular waveforms, etc. The circuitry comprises an oscillator which supplies an oscillating signal to an up/down binary counter which counts occurrences of said signal. The binary output of the counter is converted into an analog signal and supplied to an output buffer stage. An offset control is associated with the output stage whereby an offset may be introduced into the output signal produced by the output stage. A strobe control is also associated with the output stage for providing selective transmission of the output signal of the stage to an output terminal in accordance with a strobe control signal applied to the output stage. The strobe control signal and the offset control signal determine the output signal waveform shape. Circuitry is also provided with the capability of greatly increasing the normal frequency of the oscillator for correspondingly reducing the time required for diagnostic testing of the circuitry.

Circuitry for generating ramp type signals

An integrator circuit is reset at predetermined engine crank angles to develop a sawtooth waveform representing engine crank angle. A comparator circuit, including an adjustable, voltage source output, is connected in a closed feedback loop around the integrator to regulate the peak of the sawtooth to a predetermined magnitude which is independent of engine speed, and, hence, independent of the sawtooth frequency. The analog output of the comparator represents engine speed. An adjustable calibration resistor in the integrator adjusts the integrator output to secure a desired relationship between the output of the comparator circuit and the frequency of the sawtooth. The complete circuit requires only two operational amplifiers and a small number of passive circuit elements.

Circuit for generating a sawtooth engine crank angle signal and an

An electronic engine spark timing controller contains a throttle position transducer circuit and an intake manifold vacuum transducer circuit which provide respective signals representing the throttle position and the magnitude of intake manifold vacuum. Each of these two circuits contains a novel configuration of electronic circuit elements to develop an output electrical waveform composed of repetitive pulses each of which has a pulse width representative of the corresponding mechanical input signal which is supplied to the circuit via a transducer in the form of a coil whose inductance is varied in accordance with the mechanical input signal. The coil in each transducer circuit forms a portion of an RL type monostable circuit which exhibits an electrical transient when triggered. Both transducer circuits are triggered from a free-running pulse generator which is set to generate pulses at a fixed frequency. The pulse width of the trigger pulses used to trigger the transducer circuits is appreciably less than the pulse width of the output pulses of the transducer circuits, and each transducer circuit contains a feedback circuit which, when the monostable has been triggered by a pulse from the pulse generator, enables the electrical transient generated therein to continue. The output signals are used in conjunction with additional circuitry to provide spark timing control for the engine.

Transducer circuits

A variable inductance transducer for providing, via inductance modulation, an electrical output signal which is representative of a mechanical input signal. The transducer comprises a cylindrical plastic bobbin on which an inductive coil is wound. A pair of electrical terminal receiving sockets for a pair of electrical terminals are formed at one end of the bobbin and a pair of electrical terminals are disposed therein. The ends of the wire forming the coil are soldered to the terminals. A protective enclosure is molded around the coil and the portions of the terminals received in the sockets to enclose the coil and lock the terminals in place in the sockets. A ferrite core is slidably arranged within a central axial bore in the bobbin to vary the inductance of the transducer in accordance with the axial portion of the core. The core is selectively positioned by means of an actuating mechanism including a flexible actuating member and in one disclosed embodiment the actuating mechanism is a vacuum servo while in another disclosed embodiment, it is a formed wire rod. The transducer is of reasonable cost and possesses accuracy, repeatability and response which makes its usage in an engine spark timing control system significantly advantageous.

Method of calibrating variable inductance transducers

A variable inductance transducer for providing, via inductance modulation, an electrical output signal which is representative of a mechanical input signal. The transducer comprises a cylindrical plastic bobbin on which an inductive coil is wound. A pair of electrical terminal receiving sockets for a pair of electrical terminals are formed at one end of the bobbin and a pair of electrical terminals are disposed therein. The ends of the wire forming the coil are soldered to the terminals. A protective enclosure is molded around the coil and the portions of the terminals received in the sockets to enclose the coil and lock the terminals in place in the sockets. A ferrite core is slidably arranged within a central axial bore in the bobbin to vary the inductance of the transducer in accordance with the axial position of the core. The core is selectively positioned by means of an actuating mechanism including a flexible actuating member and in one disclosed embodiment the actuating mechanism is a vacuum servo while in another disclosed embodiment, it is a formed wire rod. The transducer is of reasonable cost and possesses accuracy, repeatability and response which makes its usage in an engine spark timing control system significantly advantageous.

Vacuum servo actuated variable inductance transducer

Variable inductance transducer

Variable inductance transducers

A circuit for generating a throttle advance signal for use in an electronic engine spark timing control system contains: a throttle position transducer circuit which develops a constant frequency pulse train wherein the width of the pulses is modulated in accordance with throttle position derived from a throttle position transducer; a pulse to analog conversion circuit with ambient air temperature compensation which converts the pulse train into a temperature compensated analog signal representative of throttle position; and a throttle rate circuit which monitors the rate of change of throttle position to provide a throttle rate signal whose sensitivity is inversely proportional to ambient air temperature but whose magnitude is independent of ambient air temperature. The throttle advance signal is a function of both the throttle position signal and the throttle rate signal. The throttle advance signal is used to adjust engine spark timing in accordance with throttle operation.

Circuit for generating a temperature compensated throttle advance signal

Transducer circuits for providing pulses whose widths are representative

A control system for an internal combustion engine contains a novel programmed control function circuit which contains: an accumulation function circuit for developing an accumulation function representative of the duration for which the engine has been operating in selected operating modes; a transducer circuit which develops a signal representative of the instantaneous value of a selected engine operating parameter; and a modulation circuit which modulates the two to develop a programmed output signal which is utilized in controlling the engine. In the preferred embodiment, the accumulation function is representative of the duration for which the engine has been operating at idle and non-idle conditions and the selected operating parameter is engine manifold vacuum; the modulation circuit develops from these, a programmed vacuum advance signal utilized in controlling the spark timing advance for the ignition system of the engine.

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Sterling Heights, MI, United States of America

LaVerne Andrew Caron