Patent ID: 6958460

Claim:
Device for machining by electroerosion, comprising an electrical circuit with a voltage source (U 1 , U 2 ) connected to a supply network (A), arranged to produce current impulses in a load circuit comprising an electrode-tool (EO) and an electrode-workpiece (EP) constituting opposite poles of a working gap (GA) in series with at least one self-induction element (L 1 , LL), the electrical circuit comprising: a double voltage source (UD) comprising a first (U 1 ) and a second (U 2 ) voltage source connected galvanically together by one of their poles, said double source (UD) being connected to the load circuit by at least four separate branches (B 1 to B 4 ), switching means to produce by selective connection of said branches, at least two slopes of increasing current and at least two slopes of decreasing current, said branches being arranged such that the excess self-induction energy of the electrical circuit not consumed by the erosive discharges will be returned to the double source (UD), transfer means (PO) being provided to effect a transfer of energy between the two voltage sources (U 1 , U 2 ) of the double source (UD), and elements (C) to connect either the first (U 1 ) or the second (U 2 ) voltage source to the supply network (A).