Electric welding machine having a power circuit to limit voltage fluctuations induced in the mains

The present invention concerns an electric welding machine having a power circuit for supplying power to the welding machine from the mains. The power circuit comprises: an AC/DC converter stage (2), designed to receive an AC voltage (V AC ) from said mains at its input and to generate a first DC voltage (V rect ) at its output; an up converter stage (3), designed to receive said first DC voltage (V rec t) at its input and to generate a second DC voltage (V DC ) at its output; an output stage (10) in electric communication with said up converter stage (3), and designed to generate an output voltage (V sal ) suitable for the welding process at its output, and a pair of output terminals (4A, 4B) designed to have a load connected thereto, said output voltage (V sal ) being available at said output terminals.; The invention is characterized in that it comprises control means (6) for controlling said up converter stage (3) as a function of the value of a reference signal (Iref), check means (20) being provided for generating said reference signal (Iref), which are configured to receive at their input at least the value of said second voltage (V DC ) on said energy accumulation means (5), so that said energy accumulation means (5) are able to absorb power changes of said mains as said output voltage (V sal ) changes, due to the power absorbed by the load, to limit a voltage fluctuation induced in said mains.