A welding apparatus for welding workpieces by means of a welding arc which is ignited between a non-consumable welding electrode and the workpieces and produces a molten pool, wherein the welding is performed in a welding process including a plurality of welding cycles, the parameters of which can be set via an interface of the welding apparatus. Each welding cycle of the welding process has a high-current welding phase, during which a high welding current flows, and a low-current welding phase, during which a low welding current flows. In the high-current welding phase and/or in the low-current welding phase of, with the relevant welding cycle being set accordingly, current pulses can be applied, and at the beginning of the high-current welding phase, with the relevant welding cycle being set accordingly, high-frequency ignition pulses can be applied for the contactless ignition of the welding arc.

The invention relates to a method for contactless ignition an arc (L) between an electrode (3) and a workpiece (4) which is to be welded, for carrying out a welding process, wherein a welding current (I) and a welding voltage (U) are provided at an output (2) of a welding current source (1), wherein the welding current source (1) contains a resonance converter (5) for generating a periodically varying, preferably substantially sawtooth-shaped, open circuit welding voltage (U.sub.LL) with voltage maxima (U.sub.LL,max) which recur periodically with a repetition rate (f.sub.w) and a welding current source (1) for carrying out the igniting process. In order to achieve reliable contactless ignition of the arc (L) without complicated circuitry, the resonance converter (5) is formed by a series-parallel resonant converter, and temporally synchronous high-frequency pulses (U.sub.I,HF) are superimposed on the open circuit welding voltage (U.sub.LL) in the region of at least some of the periodically recurring voltage maxima (U.sub.LL,max) of the open circuit welding voltage (U.sub.LL).

My invention is an improvement to a welding arc igniter. My invention periodically disables the arc igniter for one or more AC half-cycles. When the igniter skips an AC half-cycle, the welding arc may not ignite, so average weld heat is reduced. AC weld heat can be adjusted in real time, by varying the fraction of AC half-cycles that are skipped. AC polarity balance can be adjusted in real time, by preferentially skipping the electrode-positive or electrode-negative half-cycles.

A system and methods for electrically starting an arc in a welding process are disclosed. The system and methods may reduce an electromagnetic interference (EMI) footprint during the arc start by reducing the average power spectral density output and broadening the frequency spectrum of the arc EMI footprint. In one embodiment, a welding system may include a welding torch and a welding power source electrically coupled to the welding torch via a weld cable configured to supply electrical energy to the welding torch. The welding power source may include pseudo-random noise (PRN) generator control logic circuitry configured to generate a dithered pulse waveform with a pseudo-randomly selected data sequence of binary values based on one or more baselines, and to apply the dithered pulse waveform to an oscillator during arc starting in a tungsten inert gas (TIG) welding process performed by the welding torch.

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.

My invention is an improvement to a welding arc igniter. My invention periodically disables the arc igniter for one or more AC half-cycles.

When the igniter skips an AC half-cycle, the welding arc may not ignite, so average weld heat is reduced.

AC weld heat can be adjusted in real time, by varying the fraction of AC half-cycles that are skipped.

AC polarity balance can be adjusted in real time, by preferentially skipping the electrode-positive or electrode-negative half-cycles.

The invention relates to a method for contactless ignition an arc (L) between an electrode (3) and a workpiece (4) which is to be welded, for carrying out a welding process, wherein a welding current (I) and a welding voltage (U) are provided at an output (2) of a welding current source (1), wherein the welding current source (1) contains a resonance converter (5) for generating a periodically varying, preferably substantially sawtooth-shaped, open circuit welding voltage (U.sub.LL) with voltage maxima (U.sub.LL,max) which recur periodically with a repetition rate (f.sub.w) and a welding current source (1) for carrying out the igniting process. In order to achieve reliable contactless ignition of the arc (L) without complicated circuitry, the resonance converter (5) is formed by a series-parallel resonant converter, and temporally synchronous high-frequency pulses (U.sub.I,HF) are superimposed on the open circuit welding voltage (U.sub.LL) in the region of at least some of the periodically recurring voltage maxima (U.sub.LL,max) of the open circuit welding voltage (U.sub.LL).

A gas tungsten arc welding system includes a welding power source including a controller comprising a memory storing a plurality of parameters that at least partially define a welding waveform. The welding waveform includes a high frequency stage, an AC arc initiation stage following the high frequency stage wherein the AC arc initiation stage comprises a plurality of AC current pulses that decrease in amplitude during a slope duration, and an AC sequencing stage following the AC arc initiation stage. The system further includes a user input in communication with the controller and configured to receive a manual activation of an increased energy AC arc initiation mode. The controller is configured to increase energy of the AC arc initiation stage, when the increased energy AC arc initiation mode is activated, by at least lengthening the slope duration of the AC arc initiation stage.

Systems and methods for initiating and/or terminating a GMAW-P welding process are disclosed. A welding-type power supply may include a power conversion circuitry configured to convert input power to welding-type power, and a controller configured to control the power conversion circuitry based on a plurality of operating parameters. In examples, the systems and methods disclosed herein implement pulsed cycles with one or more increased output parameters (such as current, pulse width, etc.) in order to jump start a pulsed welding cycle at a cold start (i.e. at initiation of a welding process), and thereby prevent a ball forming and remaining on the end of an electrode wire as the welding process continues. In a similar manner, a pulsed cycle with one or more increased parameters can be used to terminate the welding process, also preventing the ball forming and remaining on the electrode wire.

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.