Patent ID: 8389898

Claim:
Method for regulating a welding current source with a current transformer, which has a series resonant circuit on a primary side and a parallel resonant circuit on a secondary side, the series resonant circuit being supplied with a variable alternating voltage by a bridge circuit and the parallel resonant circuit providing energy to a welding process by way of a rectifier, and a control unit controlling the bridge circuit in dependence on at least one state variable of the welding current source, the method comprising: recording a primary current or a state variable on the primary side corresponding to the primary current as the state variable of the welding current source; and feeding a control signal dependent on the primary current or on the state variable on the primary side corresponding to the primary current to the control unit; wherein a resonant frequency of the welding current source is recorded as a further state variable and a value of the recorded primary current or of the state variable on the primary side corresponding thereto is corrected in dependence on the resonant frequency to form a control signal for the control unit.