Electroerosion spark machining generator - with comparator for actual and desired values of voltage versus time curve envelopes

摘要

The generator includes a control unit which produces upper and lower threshold signals as max. and min. envelopes of the voltage-versus-time curve. A second control unit compares this with the actual value in the working circuit with the spark gas and operates a third control unit to adjust the working pulse across the gap to lie within the envelope pair. This can be used to get any desired shape of envelope amplitude, repetition frequency and duty factor to suit the workpiece conditions. The response time is extremely fast and suitable for modern optimisation control systems.