Ignition coil and capacitor analyzer utilizing the zero cross overs and peak voltage of the low coil ringing voltage

Abstract

The condition of the ignition coil and capacitor of an internal combustion engine are analyzed by determining the number of zero cross-overs in the ringing of the low coil voltage as well as whether or not the low coil voltage exceeds a threshold magnitude, during the spark period of a disconnected spark plug while the engine is running. In one disclosed embodiment, the cross-overs in the low coil ringing voltage and the times that the threshold is exceeded are counted over a moderate number (such as 16) of revolutions of the distributor, and then the average number of ringing cross-overs is combined with the approximate percent of time that the threshold voltage is exceeded during that number of revolutions to present signals indicating that the ignition is normal, the coil has shorted turns or intermittent arc-overs, or that the capacitor is open. In another disclosed embodiment the cross-overs are quantized in a monostable multivibrator and integrator, to provide analog indications of the number of cross-overs to permit transference thereof through an analog multiplexer and analog to digital converter to a digital processor for analysis in a desired fashion.

Dependencies are inferred from the claim text.