An electrical circuit , comprising at least: - an electric load to be driven - a generator of an electric current waveform, and - a passive filter comprising an input connected to the generator and an output connected to the electric load to be driven, wherein the passive filter is tuned for generating an electric current waveform resulting from a conditioning of one or more harmonics of the electric current waveforms in input, wherein the passive filter is a resonant reactive filter comprising inductors and capacitors, wherein the passive filter is tuned for amplifying the first harmonic of the electric current waveform with a multiplication factor, completely or nearly completely damping the second harmonic, and amplifying the third harmonic with an amplification factor equal to one third of the multiplication factor of the first harmonic, wherein the generator of the current waveform comprises: - a generator of direct electric current, - a switching circuit able to convert the direct electric current into an electric current waveform, wherein the switching circuit comprises at least: - an active switch - a driver for generating an electrical driver signal able to switch the active switch on and off, wherein the switching circuit comprises a first inductance connected in series between the generator of direct electric current and the active switch , and the input of the passive filter is connected with an electrical node interposed between the first inductance and the active switch , wherein the load to be driven comprises a drive terminal of a second active switch, characterized in that the passive filter comprises a plurality of electrical modules including at least a first electrical module and a second electrical module, wherein each one of the at least first and second electrical modules comprises at least: - a first electric branch comprising an input terminal and an output terminal, and - a second electric branch comprising a second inductance and a first capacitance , the second electric branch being connected between the output terminal of the first electric branch of the respective electrical module and a reference potential, and wherein the input terminal of the first electric branch of the first electrical module is connected to the input of the passive filter , and the input terminal of the first electric branch of the second electrical module is connected to the output terminal of the first electric branch of the first electrical module. - an electric load to be driven - a generator of an electric current waveform, and - a passive filter comprising an input connected to the generator and an output connected to the electric load to be driven, wherein the passive filter is tuned for generating an electric current waveform resulting from a conditioning of one or more harmonics of the electric current waveforms in input, - a generator of direct electric current, - a switching circuit able to convert the direct electric current into an electric current waveform, - an active switch - a driver for generating an electrical driver signal able to switch the active switch on and off, - a first electric branch comprising an input terminal and an output terminal, and - a second electric branch comprising a second inductance and a first capacitance , the second electric branch being connected between the output terminal of the first electric branch of the respective electrical module and a reference potential, and wherein the input terminal of the first electric branch of the first electrical module is connected to the input of the passive filter , and the input terminal of the first electric branch of the second electrical module is connected to the output terminal of the first electric branch of the first electrical module. <EOS>