RF filter using aluminium oxide ceramic plate - has plate fixed to electrode end to suppress noise caused by discharges in IC engine distributor

摘要

The radio frequency filter is designed to suppress noises caused by discharges between a pair of electrodes. The filter uses an aluminium-oxide ceramic plate (4) attached to the end of one of the electrodes (2, 3). This plate is riveted to the electrode and projects 0.7 to 3 mm beyond its end (distance L). The ceramic plate contains 80% by wt. of aluminium oxide and has a curved outer edge to match the curve of the edge of the electrode structure. The electrode (2) is fastened to a rotor arm. The system is used in motor vehicle ignition circuits to silence the sparks between the electrodes in the distributors head.