An AC/DC converter has at its input a rectifier circuit connected in series with a primary winding of an isolating transformer and with a chopper switch (T1) connected to a pulse width modulation control circuit. The isolating transformer has a first secondary winding wound in the same direction as the primary winding and connected to an output line of the converter via a diode (D4). The output line is connected to an output capacitor (Cout), wherein the isolating transformer has a second secondary winding that is wound in the opposite direction to the primary winding and that is connected directly to the output line via a diode (D2).