| 摘要 |
A control system for air-carbon arc metal removal in which the arc is automatically controlled and in which the arc power is produced by either a constant potential or constant current power source. For a constant potential source, the arc current is maintained at a predetermined value by sensing the magnitude of the arc current and for a constant current source the arc voltage is maintained at a predetermined value by sensing the magnitude of the arc voltage. The presence of an arc current above a threshold is sensed for a predetermined interval to provide relative motion between the workpiece carriage and the electrode. If the electrode arc current drops below a predetermined threshold, a low current sensing circuit is actuated. If the arc current remains below the threshold for a predetermined time interval, the carriage travel is terminated. If the arc current remains below the threshold for longer than a predetermined amount of time, the electrode power is turned off. In addition, if the arc voltage drops or remains below a threshold for a predetermined time period, the electrode power is also turned off.
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