| 摘要 |
A system for controlling a welding operation provides for open-loop control of voltage applied to a wire electrode during an initial arc initiation stage of operation. The voltage may be based upon an operator set voltage. Electrode wire feed speeds may be varied during the same period. The voltage may be changed, but still open-loop controlled after initial contact between the electrode and a workpiece. The control transitions from open-loop to closed loop following the arc initiation stage, which may be a fixed interval or varied based upon various factors. Closed-loop voltage control then ensues, in which voltage may be limited to values based upon the initial open-loop voltage. The voltage may be regulated by control of SCR firing angles, such as by reference to a zero-crossing of an input AC waveform.
|
