Delphi Technologies, Inc.

John W Boyer

Raymond O Butler, Jr

Scott Birk Kesler

Daniel J O'Connor

Daniel R Harshbarger

A signal processing circuit includes a comparator having a fixed and a variable reference input for detection of a positive quasi-sinusoidal waveform pulse. A signal detection circuit includes a low pass input filter, a voltage input clamp, a variable detection threshold, and a zero crossing detector. The circuit produces an approximately square wave output substantially coinciding with the positive pulse of the quasi-sinusoidal waveform received, from a variable reluctance sensor. The circuit has a positive to negative zero crossing detector armed by a variable threshold of the positive quasi-sinusoidal pulse, thus providing variable noise immunity and a fixed phase relationship between the input and output signal for an input signal having a variable amplitude.

Variable threshold comparator interface circuit

An automotive ignition system includes a control circuit ( ) operable to drive a coil current switching device ( ) connected to an ignition coil ( ) referenced at battery voltage. The control circuit ( ) includes a drive circuit ( ) and ring damping circuit ( ) producing an inhibit signal (INH) to which the drive circuit ( ) is responsive to control the state of the coil drive signal (GD). In a single pulse ignition system; i.e., an ignition system employing a single coil charging event per combustion cycle, the ring damping circuit ( ) is responsive to a spark control signal (ESTBF) to control charging and discharging of a single capacitor (C ) to define the inhibit signal (INH). In a multiple pulse ignition system; i.e., an ignition system employing multiple coil recharging cycles following a standard initial charging dwell cycle, the ring damping circuit ( ) is responsive to the spark control signal (ESTBF) and at least two mode signals (M M ) to control charging and discharging of the single capacitor (C ) throughout the initial and subsequent coil charging cycles to define the inhibit signal (INH). In either case, the drive circuit ( ) is responsive to the inhibit signal (INH) to disable current flow through the primary ignition coil ( ) when the inhibit signal (INH) is enabled, and to enable current flow through the primary ignition coil ( ) when the inhibit signal (INH) is disabled.

Automotive ignition system with adaptable start-of-dwell ring damping

An ignition system for an internal combustion engine includes an ignition coil coupled to a spark plug in a combustion chamber of the engine, and a switch responsive to an ignition control signal for causing a primary current to flow through a primary winding ( ) of the ignition coil. A control circuit is configured to generate the ignition control signal so as to produce a plurality of sparks at the spark plug during a combustion event in the cylinder. A secondary current trip circuit in sensing relation to the secondary winding is configured to generate secondary current trip signal when the secondary current decays down past a secondary current trip threshold. The control circuit is further configured to trigger a recharge event of the multicharge operation in response to the secondary current trip signal, thereby minimizing variability in terms of the amount of energy delivered to the combustion chamber.

Multicharge ignition system having secondary current feedback to trigger start of recharge event

An ignition system for an internal combustion engine includes an ignition coil coupled to a spark plug in a combustion chamber of the engine, and a switch responsive to an ignition control signal for causing a primary current to flow through a primary winding of the ignition coil. A control circuit is configured to generate the ignition control signal so as to produce a plurality of sparks at the spark plug during a combustion event in the cylinder. A combustion detection circuit in sensing relation with the combustion cylinder is configured to generate a combustion detect signal when combustion occurs. The control circuit is further configured to terminate the generation of the ignition control signal during the combustion event in response to the combustion detect signal, thereby terminating multicharge operation when the need for further sparks is no longer present. Unnecessary spark plug wear is avoided.

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Westfield, IN, United States of America

John W Boyer