Monitoring and Controlling the E.D.M. Process

Extensive investigations were carried out to study the emitted radiation during the E.D.M. process. It was found that radiation from the region of the gap between the electrode (tool) and the workpiece is significantly different when the following four conditions: open voltage, effective discharge (sparking), arc and short circuit occur during the E.D.M. process. The sparking condition is accompanied by a comparatively high radiation level at radio frequencies above 1 MHz. During arcing, however, although relatively low radiation takes place below 0.5 MHz, there is practically no radio frequency emission at all. However, the E.D.M. process could be monitored and optimized from the emitted radio frequency signals. The emitted radio signals could be employed to develop an adaptive control system for E.D.M. machines. The reported work includes apparatus, circuits and methods for monitoring the E.D.M. process and controlling such a process in accordance with the monitoring carried out.