Abstract: The aim of the invention is to enable a stable welding process. This is achieved in that a welding device is supplied with a supply power by an energy source and converts at least a part of the supply power into a welding power in order to generate a welding arc, wherein the welding power is regulated by specifying a welding current. For this purpose, the supply voltage is determined, and the maximum supply current that can be delivered to the welding device from the energy source is specified. A maximum supply power is calculated using the supply voltage and the maximum supply current. The maximum welding power that is delivered by the welding device is determined from the maximum supply power, and the welding power is limited to the maximum welding power that can be delivered.

Abstract: 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 (ULL) with voltage maxima (ULL,max) which recur periodically with a repetition rate (fw) and a welding current source (1) for carrying out the igniting process.

Abstract: 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 (ULL) with voltage maxima (ULL,max) which recur periodically with a repetition rate (fw) and a welding current source (1) for carrying out the igniting process.

Abstract: To enable in a circuit arrangement (8) with a transformer with center tap the voltage measurement on the secondary side simply and safely, it is provided that at least two series-connected resistors (R3, R4) are connected between the two outer connections (A1, A2) of the secondary side of the transformer (T) to form a measurement point (P) between the two resistors (R3, R4), and a voltage measurement unit (V) is provided to measure the voltage (UP) between the measurement point (P) and the second output pole (13), which corresponds to the output voltage (UA).

Abstract: In order to set the output voltage of a resonant converter to a desired value by means of a simple additional circuit while the resonant converter is in open circuit operation, it is intended that at least one capacitor each (C1, C2) is connected in parallel to the electrical switching elements (S1, S2) of the secondary side of the resonant converter (1).

Abstract: To enable in a circuit arrangement (8) with a transformer with center tap the voltage measurement on the secondary side simply and safely, it is provided that at least two series-connected resistors (R3, R4) are connected between the two outer connections (A1, A2) of the secondary side of the transformer (T) to form a measurement point (P) between the two resistors (R3, R4), and a voltage measurement unit (V) is provided to measure the voltage (UP) between the measurement point (P) and the second output pole (13), which corresponds to the output voltage (UA).

Abstract: In order to set the output voltage of a resonant converter to a desired value by means of a simple additional circuit while the resonant converter is in open circuit operation, it is intended that at least one capacitor each (C1, C2) is connected in parallel to the electrical switching elements (S1, S2) of the secondary side of the resonant converter (1).