The present invention relates to a circuit arrangement and to an actuating method for a DC voltage converter, in particular a DC voltage converter with phase-shifted full-bridge topology, wherein power can also be transmitted from the primary side to the secondary side when the electrical voltage on the primary side undershoots the product of the electrical voltage on the secondary side and the transmission ratio of a transformer in the DC voltage converter. In this way, for example, a capacitor on the primary side of the DC voltage converter can be discharged to a safe, low voltage level.