The arc duration and the contact resistance at every contact operation were measured in Ag and AgCu10% and (AgSnO{sub}2)12% contacts. Measurements were carried out under the source voltage 48V (constant) and resistive load. The closed contact currents were varied form 0.4 to 4A. As a result, transition boundary closed current of AgSnO{sub}2 was smallest than that of Ag and AgCu. In Ag, lo that transits to the gaseous phase was greatly different in the case of preliminary experiment and large number of continuous switching. Furthermore, the contact resistance of AgCu and AgSnO{sub}2 greatly changed near the transition boundary from the metallic to the gaseous phase arc.
展开▼
