Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A variable inductance transducer for providing, via inductance modulation, an electrical output signal which is representative of a mechanical input signal. In a preferred embodiment the mechanical input signal is the intake manifold vacuum of an internal combustion engine and the electrical output signal is utilized in an engine spark timing control system to adjust the spark timing in accordance with the intake manifold vacuum. The transducer comprises an actuating mechanism in the form of a vacuum servo which axially positions a ferrite core within a central axial bore of a plastic bobbin on which an inductive coil is wound to thereby vary the inductance of the coil in accordance with the vacuum applied to the servo. The bobbin and coil are enclosed in plastic to form a separate unit which is assembled into the transducer by being controllably lodged within the bore of a molded plastic element forming a portion of the body of the transducer.

Abstract: A housing containing a pair of electronic circuit boards removably mounts on the side of an engine air filter housing. The circuit board housing has a generally concave inner face matching the convex contour of the air filter housing side wall and is disposed over air circulation openings in the air filter housing side wall. In a first embodiment, the circuit board housing is of one-piece construction and the electronic circuit boards are disposed interiorly of the outer wall of the circuit board housing and in generally parallel relationship therewith. In a second embodiment, the circuit board housing is of two-piece construction having upper and lower halves. In this embodiment, the circuit boards are horizontally disposed, one each in each of the two housing halves. Connectors for effecting connection of the circuit boards with the other components of the system which are located exteriorly of the air cleaner housing extend through holes in the circuit board housing.

Abstract: 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.

Abstract: A variable inductance transducer for providing, via inductance modulation, an electrical output signal which is representative of a mechanical input signal. In a preferred embodiment the mechanical input signal is the intake manifold vacuum of an internal combustion engine and the electrical output signal is utilized in an engine spark timing control system to adjust the spark timing in accordance with the intake manifold vacuum. The transducer comprises an actuating mechanism in the form of a vacuum servo which axially positions a ferrite core within a central axial bore of a plastic bobbin on which an inductive coil is wound to thereby vary the inductance of the coil in accordance with the vacuum applied to the servo. The bobbin and coil are enclosed in plastic to form a separate unit which is assembled into the transducer by being controllably lodged within the bore of a molded plastic element forming a portion of the body of the transducer.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A housing containing a pair of electronic circuit boards removably mounts on the side of an engine air filter housing. The circuit board housing has a generally concave inner face matching the convex contour of the air filter housing side wall and is disposed over air circulation openings in the air filter housing side wall. In a first embodiment, the circuit board housing is of one-piece construction and the electronic circuit boards are disposed interiorly of the outer wall of the circuit board housing and in generally parallel relationship therewith. In a second embodiment, the circuit board housing is of two-piece construction having upper and lower halves. In this embodiment, the circuit boards are horizontally disposed, one each in each of the two housing halves. Connectors for effecting connection of the circuit boards with the other components of the system which are located exteriorly of the air cleaner housing extend through holes in the circuit board housing.

Abstract: A pickup operatively coupled with an internal combustion engine develops a train of bi-polar pulses wherein each bi-polar pulse is generated at a predetermined engine crank angle and each bi-polar pulse comprises a leading pulse portion of one polarity and a trailing pulse portion of opposite polarity. A bi-stable circuit is switched to a set condition in response to a given magnitude of the trailing pulse portion of each bi-polar pulse and is switched to a reset condition in response to a given magnitude of the leading pulse portion of each bi-polar pulse. A monostable circuit is operatively coupled with the bi-stable circuit to provide an output pulse of predetermined duration in response to the switching of the bi-stable circuit from the reset to the set condition. A transistor has its emitter-collector circuit connected across the capacitor of the engine spark timing controller integrator circuit and its base terminal connected to the output of the monostable circuit.

Abstract: 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.