Moving characteristics of cathode spots of break arcs occurring between Ag and Pd electrical contacts

摘要

Break arcs are generated between Ag and Pd contacts in a DC48V and 9A resistive circuit. The behavior of the break arcs on cathode surface is observed with a high-speed camera. The exposure time of high-speed camera is 12μs and 1μs. The following results are shown. For Ag contacts, the cathode spot region moves with the time progress and the cathode spot moves or jumps in a shorter time than 1μs. For Pd contacts, multiple cathode spots are observed and the number of the cathode spot decreases with decreasing of exposure time 12μs to 1μs. The cathode spot jumps at intervals of a few micro seconds.