The invention concerns a converter which includes two input terminals and two output terminals, a main transformer presenting primary and secondary windings connected between the input terminals and the output terminals respectively, a switching device, a first inductance and a first capacitance forming a first resonant circuit with the primary winding of the main transformer, a wound regulation transformer, presenting a primary winding, and a secondary winding connected in series with one of the windings of the main transformer, a switching device, a second inductance and a second capacitance forming a second resonant circuit with the primary winding of the regulation transformer and with this switching device and a command forming the first and second resonant circuits at a resonance frequency less than or equal to the resonance frequencies of the resonant circuits.