Snap-on Inc.

Snap-on Technologies, Inc.

Robert R Bryant

Kenneth A McQueeney

James M Normile

Timothy J Spencer

Chee K Fong

A coil-on plug testing apparatus for detecting a weak field output by a shielded coil-on plug ignition and generating an output signal representing an ignition signal includes a capacitive sensor attachable to a coil-on-plug device for detecting an electric field generated by the shielded coil-on plug device during a firing event and generating and outputting a voltage in response thereto. A signal processing circuit electrically coupled to the capacitive sensor is configured to generate an output signal in response to variations in the voltage output by the capacitive sensor in response to a detected electric field. The signal processing circuit comprises an amplifier configured to amplify an output voltage of the capacitive sensor.

Coil on plug capacitive signal amplification and method of determining burn-time

A coil-on plug testing apparatus generates an output signal representing an ignition signal. The testing apparatus includes an inductive sensor for detecting an electromagnetic flux generated by a coil-on plug device during a firing event and generating and outputting a voltage in response thereto, and a signal processing circuit electrically connected to the inductive sensor for generating an output signal in response to variations in the voltage output by the inductive sensor. A method for determining burn time for a coil-on plug ignition includes disposing an inductive sensor adjacent to a coil-on plug ignition housing, using the inductive sensor to detect an electromagnetic flux output by the coil-on plug ignition during a period encompassing at least one firing section, and determining a burn time by identifying a firing line, identifying an endpoint of a spark line and determining a time period therebetween.

Coil on plug inductive sampling method

An apparatus for measuring ignition charge signals produced by coils of coil-on-plug devices of an internal combustion engine. A signal detector comprises an insulating substrate having a first conductive planar layer on a first side and a second conductive planar layer on a second side. The first layer is coupled to a signal wire and the second layer is coupled to a ground wire. When the signal detector is held in close proximity to the coil of the coil-on-plug, ignition signals generated by the coil and passing to the plug are detected. The detected signals may be coupled to a signal analyzer for display and analysis. The amplitude of the signal that is output by the signal detector may be adjusted to different coils having different output signal strengths by modifying the ratio of the surface areas of the first layer and the second layer.

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San Jose, CA, United States of America

Robert R Bryant