Device for detecting the concert of a machining gap during initialization in the case of a spark erosion machining process

摘要

An apparatus is disclosed for sensing conditions in a machining gap by detecting a current flow therethrough. The normal application of low power pulses from an oscillator circuit to a power switching circuit is delayed for a predetermined period of time. During this period of time, a sensing signal is applied to the machining gap through a high resistance gap sensing circuit; and the current through the sensing circuit is detected thereby providing an accurate and reliable indicator of conditions in the machining gap.