INSULATION TESTER FOR WIRE CUT ELECTRICAL DISCHARGING MACHINE

摘要

An insulation tester for the captioned machine is capable of deteecting the insulation resistance between the wire electrode and a work piece without using any particular power source other than the one for machining. The voltage between the wire electrode (5) and the work piece (6) is detected while a capacitor (4) is being charged when a semiconductor switching element (3) for discharging is turned off and a switching element (2) for charging is turned on. If the detected voltage is not greater than a reference value, it is determined that the insulation between the wire electrode and the work piece is insufficient, hence, outputting a signal to indicate a defective insulation.