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.