Method of operating a spark erosion machine and a circuit for performing the method

Claim 1

MEANS FOR CONTROLLING DISCHARGE ACROSS A SPARKERODING GAP BETWEEN A WORKPIECE AND A WORKING ELECTRODE IN A SPARK EROSION MACHINE, COMPRISING A CHARGING CIRCUIT INCLUDING SWITCH MEANS AND STORAGE CONDENSER MEANS AND MEANS TO CREATE ENERGY FOR STORING BY SAID LATTER MEANS AND DISCHARGE ACROSS THE SAID GAP, FURTHER CIRCUIT MEANS CONNECTED ACROSS THE SAID GAP FOR SUPPLYING A REFERENCE POTENTIAL AND INCAPABLE ITSELF OF MAINTAINING A DISCHARGE ACROSS SAID GAP, SAID FURTHER CIRCUIT MEANS INCLUDING VOLTAGE MEASURING MEANS AND BEING OPERATIVE IN SUCH A WAY DURING DEIONIZATION AND CLEANING OUT OF THE SAID GAP AND THE ESTABLISHMENT OF A SUITABLE DISTANCE BETWEEN THE WORKING ELECTRODE AND THE WORKPIECE THE BUILD-UP OF VOLTAGE ACROSS THE GAP BY SAID FURTHER CIRCUIT MEANS IS USED THROUGH SAID MEASURING AND SWITCH MEANS AND WHEN THE VOLTAGE HAS REACHED A PREDETERMINED VALUE LESS THAN THE SPARKING VOLTAGE TO TRIGGER THE CHARGING OF THE SAID STORAGE MEANS TO SPARKING POTENTIAL.