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