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.

A system and method for submerged arc welding. The system advances a consumable welding electrode toward a workpiece, and then stops the advancement when the consumable electrode makes contact with the workpiece. The system provides a preheating current level through the consumable welding electrode proximate the workpiece while the consumable welding electrode is in contact with the workpiece during a preheating period of time to preheat the portion of the consumable welding electrode without establishing an arc. The system then retracts the consumable welding electrode from the workpiece and increases the preheating current level to a welding current level over an arc establishment period of time to establish an arc between the consumable welding electrode and the workpiece. The system then begins to form a weld by advancing the consumable welding electrode toward the workpiece again, resulting in melting the consumable welding electrode and depositing molten metal onto the workpiece.

Embodiments of the present invention are engine drive welding and/or cutting systems which optimize the utilization of engine drive systems, including hybrid engine drive systems. Embodiments include modular systems which allow for the remote utilization of a battery powered module which can be separated from an engine drive generator power supply. Other embodiments include engine drive power supplies that can communicate with a load coupled to the power supply, such as welders, cutters and wire feeders to determine an optimum operational level. Further embodiments include engine drive power supplies that can be coupled together to optimize fuel and system usage.

A method and apparatus for controlling arc/short between a wire and a work piece is described. A current path parallel to the wire/work is provided. The voltage drop across the parallel path can be preset, to limit the wire/work voltage, or it can be controlled to a desired level. The control can be in response to feedback.

An arc start adjustment device adjusting an arc start procedure in a welding process comprises an obtainment unit that obtains welding data indicating a welding state during or after a welding process, and a procedure adjustment unit that adjusts the arc start procedure such that the cycle time of the welding process is shortened based on welding data obtained by the obtainment unit.

An arc start adjustment device adjusting an arc start procedure in a welding process comprises an obtainment unit that obtains welding data indicating a welding state during or after a welding process, and a procedure adjustment unit that adjusts the arc start procedure such that the cycle time of the welding process is shortened based on welding data obtained by the obtainment unit.

A grinding-free welding method for full-position multi-layer multi-pass welding of a pipeline, includes the following steps: preparing before welding, positioning and aligning, and performing root welding; respectively carrying out clockwise and anticlockwise arc welding on a thermal welding layer, filling layers and cover surface layers, controlling arcing in a segmented mode in a preset lap joint area by means of non-consumable electrode welding and consumable electrode welding, and then carrying out subsequent welding by means of consumable electrode welding. The method controls arcing in a segmented mode by means of non-consumable electrode welding and consumable electrode welding, and carries out subsequent welding by means of consumable electrode welding. The non-consumable electrode welding process is free of welding wire filling and a workpiece arcing area can be heated, then welding wire filling is carried out by means of consumable electrode welding.

A grinding-free welding method for full-position multi-layer multi-pass welding of a pipeline, includes the following steps: preparing before welding, positioning and aligning, and performing root welding; respectively carrying out clockwise and anticlockwise arc welding on a thermal welding layer, filling layers and cover surface layers, controlling arcing in a segmented mode in a preset lap joint area by means of non-consumable electrode welding and consumable electrode welding, and then carrying out subsequent welding by means of consumable electrode welding. The method controls arcing in a segmented mode by means of non-consumable electrode welding and consumable electrode welding, and carries out subsequent welding by means of consumable electrode welding. The non-consumable electrode welding process is free of welding wire filling and a workpiece arcing area can be heated, then welding wire filling is carried out by means of consumable electrode welding.

Methods and devices for two-channel welding arc ignition and, more particularly, to ionizing an area of a contact between an electrode and articles to be welded. Methods and devices for igniting an arc discharge and welding.