The present invention relates to a converter secondary circuit having a main output (2) and an auxiliary output (7), the secondary circuit comprising a first synchronous rectifier that is self-controlled and generates a rectified voltage for the main output (2), and said auxiliary output including a second synchronous rectifier receiving at its input said rectified voltage and being regulated by an auxiliary regulation control circuit (8) having a synchronization input (8B). According to the invention, said synchronization input (8B) receives a synchronization signal which is at zero when said rectified voltage is not at zero.
