ELECTRIC DISCHARGE MACHINE

PURPOSE:To prevent retracton phenomena likely to occur when electric discharge processing is carried out, by furnishing an electric discharge machine with a means to boost the output voltage of an equalizer circuit up to a level, at which the relative feed direction of the work to be prccessed with respect to the electrode becomes advancing, using electric discharge machining start singals. CONSTITUTION:An equalizer circuit HK2 is applied to a wire-cut electric discharge machine, and resistance R3 therein is connected in parallel with a series circuitry composed of a resistance R5 and a switch SW which is turned on when the output signal e from an AND gate AND2 is ''1''. It is also equipped with a multi-vibrator M, which turns the output signal d into ''1'' for a certain specified period when the signal a is rising. Thus the electric discharge machine, in which a servo feed system is incorporated to control the relative feed of the work to be processed W with the electrode P, is equipped with a means to boost the output voltage of the equalizer circuit HK2 up to a level, at which the relative feed direction of the work with the electrode P becomes at least advancing, using electric discharge start signals.