Abstract
Suppression of electromagnetic noise at the distributor gap for the automotive ignition system are studied. Noise frequency spectrum electrode materials and configusations are presented on the same base of the breakdown conditions in order to compensate the large dependency of the breakdown voltage on the noise levels.
A wide gap or a piled electrode which accompanies a dielectric material at the tip is useful for suppression of the noise levels. ZrO2-ZnO ceramic electrodes having different resistivity are tested and found to show very low noise levels.
Breakdown voltage of the ceramic electrodes are low and more stable than other electrodes. But the noise levels of the ceramic electrodes are fair lower than that expected by the low breakdown voltages.
