Abstract: An ignition distributor for an internal combustion engine is provided with a novel rotor electrode which substantially reduces radio frequency interference generated by spark discharges across the rotor gap. At least the tip segment of the rotor electrode is formed of a composite material consisting of a first phase of fibers of a dielectric material interspersed with a second phase of a conductive material. In operation, dielectric fibers protrude from the conductive phase into the gap promoting ionization therein so that electrical discharge occurs at voltages where radio frequency signal production is substantially suppressed.

Abstract: An ignition distributor for an internal combustion engine is provided with a novel rotor electrode which substantially reduces radio frequency interference generated by spark discharges across the rotor gap. At least the tip segment of the rotor electrode is formed of a composite material consisting of a dielectric phase interspersed with a conductive metal phase. In operation, the dielectric phase protrudes from the surface of the electrode promoting ionization in the rotor gap so that electrical discharge occurs at voltages where radio frequency signal production is substantially suppressed.