ARC DETECTION AND CONTROL APPARATUS

摘要

ARC DETECTION AND CONTROL APPARATUS Arc detection and control apparatus for a high power high voltage gas laser with a constant current power supply comprises a circuit responsive to changes in voltage across the laser electrodes for disconnecting the power supply when the voltage change exceeds a predetermined limit. The circuit monitors a small proportional value of the interelectrode voltage through an optical coupler and has a multiplier circuit for converting detected voltage changes and the differential thereof into pulses with a constant amplitude for fixed percentage changes of the electrode voltage and into pulses with increasing amplitudes for proportionally greater electrodes voltage changes. This circuit normalizes and filters the resultant pulses and permits them to be compared to a reference voltage in a comparator circuit. When the pulse amplitude exceeds the value of the reference voltage a control apparatus is actuated which disconnects the power supply from the laser electrodes.