Control of Electromagnetic Radiation from Motor Vehicles

The most effective means of controlling radiation of electromagnetic (EM) energy from the ignition system of motor vehicles is to deal with it right at its sources, i.e., the spark plug and distributor rotor gaps. This paper is concerned with the observation of the breakdown of these gaps and its associated EM radiation, and with the development of cost-effective means by which EM radiation control is achieved. Past and present suppression techniques developed for the gaps at the spark plug and the distributor rotor are discussed. In addition, comparisons of modified and unmodified distributor rotors are given in terms of spectrum analyzer measurements and SAE J551 measurements.