An electric welding machine having a power circuit for supplying power to said welding machine from the mains, said power circuit comprising: - an AC/DC converter stage, designed to receive an AC voltage from said mains at its input and to generate a first DC voltage (Vrect) at its output; - an up converter stage, designed to receive said first DC voltage (Vrect) at its input and to generate a second DC voltage at its output; - an output stage is in electric communication with said up converter stage, and designed to generate an output voltage (Vsal) suitable for the welding process at its output; - a pair of output terminals (4A, 4B) designed to have a load connected thereto, said output voltage (Vsal) being available at said output terminals; - energy accumulation means interposed and in electric communication between the output of said up converter stage and the output stage; characterized in that it comprises control means for controlling said up converter stage as a function of the value of a reference signal (Iref), check means for generating said reference signal (Iref), which are configured to receive at their input at least the value of said second voltage on said energy accumulation means, so that said energy accumulation means 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 voltage fluctuations of flicker type induced in the mains during welding, and that said energy accumulation means comprise a plurality of capacitor banks which are sized as a function of the maximum and minimum operating voltage admissible by said up converter stage as well as the rated power of said welding machine, said plurality of capacitor banks being configured to act as energy flywheel and, as power drawing changes occur, being configured to absorb fluctuation of the power being drawn and, as a result, to limit the noise to the loads electrically proximate the welding machine. - an AC/DC converter stage, designed to receive an AC voltage from said mains at its input and to generate a first DC voltage (Vrect) at its output; - an up converter stage, designed to receive said first DC voltage (Vrect) at its input and to generate a second DC voltage at its output; - an output stage is in electric communication with said up converter stage, and designed to generate an output voltage (Vsal) suitable for the welding process at its output; - a pair of output terminals (4A, 4B) designed to have a load connected thereto, said output voltage (Vsal) being available at said output terminals; - energy accumulation means interposed and in electric communication between the output of said up converter stage and the output stage; characterized in that it comprises control means for controlling said up converter stage as a function of the value of a reference signal (Iref), check means for generating said reference signal (Iref), which are configured to receive at their input at least the value of said second voltage on said energy accumulation means, so that said energy accumulation means 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 voltage fluctuations of flicker type induced in the mains during welding, and that said energy accumulation means comprise a plurality of capacitor banks which are sized as a function of the maximum and minimum operating voltage admissible by said up converter stage as well as the rated power of said welding machine, said plurality of capacitor banks being configured to act as energy flywheel and, as power drawing changes occur, being configured to absorb fluctuation of the power being drawn and, as a result, to limit the noise to the loads electrically proximate the welding machine.