Power supply for wire electric discharge machining

摘要

In a power source apparatus for wire electric discharge machining capable of applying voltages of both of positive and opposite polarities to a gap between a wire electrode (1a) and a workpiece (2), there is provided a controller (14) for applying a first voltage pulse to the gap for predetermined time T1 and then applying a second voltage pulse of a polarity opposite to the first voltage pulse for predetermined time T2a necessary for the gap voltage to become a predetermined voltage lower than or equal to a voltage Va capable of starting an electric discharge after a lapse of predetermined time t set for prevention of breakage of a switch. The apparatus is used in machining for performing at least two machining operations selected from machining in machining liquid, machining in mist and machining in gas. Wire electric discharge machining with high reliability suitable for high-accurate machining can be implemented.