Welding type power supply for short circuit arc welding and method of controlling the power supply

摘要

A method and apparatus for providing welding-type power includes a wire feeder (104) that provides wire (209) to an arc and a power supply (102) that provides power to the arc. A reversible wire feed motor (301,302) moves the wire (209) towards and away from the arc. A controller (106) controls the reversible wire feeder motor (301,302) to reverse at least once per process cycle, and/or controls the power source (102) to provide a desired mean arc current, and/or controls the reversible motor (301,302) in response to short detection and short clearing, and/or controls the reversal frequency in response to pool oscillation frequency. A wire feed motor output is slaved to an average of the reversible motor output. The controller (102) may include various control modules, such as a mean arc current control module, and/or a short detection feedback circuit. The reversible motor (301,302) is a stepper motor, that incrementally turns in a series of steps having a given angle in another embodiment. The controller (102) includes a step size output and the given angle is varied in response to the step size output.