Novel power supply topology for large working gap dry EDM

For material removal in rotor balancing machines, dry Electrical Discharge Machining (EDM) with large working gap is an advantageous alternative to the common mechanical drilling, grinding or laser drilling. This paper presents a novel topology of a power supply required for such an application. It has an increased ignition voltage capability of up to 10 kV compared to standard power supplies with only 300 V, which allows for an increase in working gap distance to millimeters. The control of the current pulse amplitude and length are described. Voltage and current measurements verify the design considerations prove the feasibility of the proposed power supply.