ELECTRICAL DISCHARGE MACHINING APPARATUS

摘要

A circuit for controlling an EDM process in which a logical monitoring circuit is used to detect a wrong discharge pulse out of the simultaneous occurrence and absence of certain electrical characteristics in the electrical discharge, as for example the absence of a high frequency component on the discharge voltage, as a criterion for an arc condition, the circuit including an input device connected to supply test signals to the monitoring circuit to simulate a wrong discharge pulse and thus enable checking of the monitoring circuit.