A welding apparatus having a waveform compensation device, a power section coupled to the waveform compensation device which generates a welding waveform in accordance with a signal from the waveform compensation device, and a frequency detection device which detects at least one of a voltage, current and power of a welding arc and determines a shorting frequency of the arc. The waveform compensation device adjusts at least a portion of the welding waveform based on an output from the frequency detection device.

Welding-type power supplies with adjustable AC current commutation thresholds are disclosed. An example welding-type power supply includes an interface device to receive a commutation selection input, a power converter to convert input power to welding-type power, a commutator circuit to output alternating current (AC) welding-type power and to control a polarity of the AC welding-type power, and a control circuit. The control circuit determines a threshold output current based on the commutation selection input, determines an output current and a polarity of the AC welding-type power and, when the output current is less than the threshold output current, controls the commutator circuit to change the polarity of the AC welding-type power.

Welding-type power supplies with adjustable AC current commutation thresholds are disclosed. An example welding-type power supply includes an interface device to receive a commutation selection input, a power converter to convert input power to welding-type power, a commutator circuit to output alternating current (AC) welding-type power and to control a polarity of the AC welding-type power, and a control circuit. The control circuit determines a threshold output current based on the commutation selection input, determines an output current and a polarity of the AC welding-type power and, when the output current is less than the threshold output current, controls the commutator circuit to change the polarity of the AC welding-type power.

Systems and methods to provide welding-type arc starting and stabilization with reduced open circuit voltage are disclosed. An example welding-type power supply includes: power conversion circuitry configured to convert input power to welding-type power; and control circuitry configured to: control the power conversion circuitry to output a voltage pulse at a first voltage; determine whether the power conversion circuitry outputs current during the voltage pulse; in response to determining that there is less than a threshold output current during the voltage pulse, control the power conversion circuitry to turn off an output or output a second voltage that is less than the first voltage; and in response to determining that the power conversion circuitry outputs at least the threshold output current during the voltage pulse, control the power conversion circuitry to output the welding-type power.