Patent ID: 7608795

Claim:
An electrical discharge machining device comprising a tool electrode (F) and a workpiece electrode (P) forming the poles of a machining gap (G), at least one voltage/current source (U 1 ) connected by an electrical circuit (E) to the tool electrode (F) and to the workpiece electrode (P) and configured for generating electrical pulses and for establishing the initiation of electrical discharges between the tool electrode (F) and the workpiece electrode (P), at least one capacitive element (C 1 ) close to or within contacts (W 1 , W 2 ) located between said electrical circuit (E) and the tool electrode (F), the capacitive element (C 1 ) is connected in series between the source (U 1 ) and one of the poles of the machining gap (G) wherein it prevents DC components of electrical pulses coming from the source (U 1 ) from being applied across the machining gap (G) and to allow variable current components coming from the source (U 1 ) to flow, wherein the total capacitance (Ceq) of said electrical circuit (E) is reduced with respect to the machining gap (G), wherein the tool electrode is a wire (F) and the capacitive element (C 1 ) is formed by a wire guide (WG) one part of which, in contact with the wire (F), is made of insulating material and another part of which is made of conducting material.