Rising Current Detecting Sensor for Current Pulse On-Time in Electrical Discharge Machining

Electrical Discharge Machining (EDM) is a non-conventional machining process with a precise controlled of an electrical discharge through a gap that occurs between an electrode and a workpiece in the presence of a dielectric fluid. Through EDM process, the conductive workpiece materials are melted according to the negative shape or image of the electrode. Controlling the EDM pulses is necessary to make a stable process. The signal processing speeds in rising and falling conditions are parameter of a stable process in EDM. This paper presents a control circuits strategy for rising current detection of pulse on-time. The results show the time delay when the electric current rises and the output from the digital isolation is about 1 µs with Ton 1 ms and Toff 1 ms. The time delay value is about 2 µs with Ton 1.5 ms and Toff 500 µs. With this strategy, it is expected that it will be able to increase the reading speed of the sensor in controlling the EDM system.