A welding current source for providing a welding current and a welding voltage at an output in order to carry out an arc welding process includes an input-side rectifier, an inverter, which is operated with a switching frequency, a transformer having a primary winding and at least two secondary windings, at least two rectifiers arranged between the secondary windings and the output, and at least one capacitor and one load resistor at the output. At least one current-limiting reactor is arranged on the second secondary winding and the load resistor for discharging the capacitor, which can be charged by the current-limiting reactor, the current-limiting reactor, and the capacitor are dimensioned in such a way that the maximum value of the no-load voltage at the output is greater than the voltage corresponding to the transmission ratio of the primary winding to the secondary winding of the transformer.