Patent ID: 6805109
Filing Date: 2004-10-19
Classification: F02D,F02P

Abstract:
An igniter circuit for a fuel ignition system designed to preclude fuel contamination from interfering with conduction of an ignition arc across an established current path between electrodes of a spark plug in the ignition system comprising:an air gap connected in series with a resistive arc probe, having a semiconductor resistive film across spark electrodes of the resistive arc probe, wherein the resistive arc probe produces an ignition arc in a fuel to be ignited; a first high voltage power supply for developing a first direct current voltage across a first capacitor, which is supplied as a voltage across the air gap and the resistive arc probe; a second high voltage power supply, operating in a pulsed mode, for supplying a second pulsed voltage across the air gap and the resistive arc probe, wherein the second pulsed voltage is substantially higher than the first direct current voltage, and the second pulsed voltage is sufficient to initiate an ignition arc, and the first direct current voltage is sufficient to sustain the ignition arc, and a diode, positioned between the second pulsed voltage and the capacitor of the first high voltage power supply, to isolate the capacitor from the second pulsed voltage; a second capacitor, coupled in parallel with the resistive arc probe, to function as a current sink to prevent the second, substantially higher pulsed voltage from the second high voltage power supply from affecting the resistive arc probe.