Abstract: In order to enable a switching process with a zero-voltage sequence (ZVS) in a full bridge DC/DC converter (1) with phase shift control without having to provide an additional inductor for this purpose, it is provided that a short-circuit is generated in the secondary-side output rectifier (5) in the transition phase from the active to the passive phase prior to switching to a passive phase of the full bridge (2), said short-cut increasing the primary current (ip) across the primary side of the transformer (T) by means of the resulting short-circuit current (ik) across the secondary side of the transformer.

Abstract: In order to enable a switching process with a zero-voltage sequence (ZVS) in a full bridge DC/DC converter (1) with phase shift control without having to provide an additional inductor for this purpose, it is provided that a short-circuit is generated in the secondary-side output rectifier (5) in the transition phase from the active to the passive phase prior to switching to a passive phase of the full bridge (2), said short-cut increasing the primary current (ip) across the primary side of the transformer (T) by means of the resulting short-circuit current (ik) across the secondary side of the transformer.

Abstract: The invention relates to an electronic circuit for a power supply device (1), in particular for a charger (2) for accumulators (3), in which the power supply device (1) is connected via input terminals (4, 5) to a power source (6), the power supply device (1) converting the supplied power from any voltage, in particular an AC voltage, into a DC voltage and this transformed power is forwarded via output terminals (7, 8) to a consumer (9), in particular the accumulator (3), in which, a switching element (10) is provided as a means of operating polarity reversal protection. The switching element (10) is disposed between at least one output terminal (7, 8) and a potential, in particular a negative potential, of the power supply device (1) and if a specific polarity appears at this output terminal (7, 8) the switching element (10) is connected through and if an opposite (incorrect) polarity appears it is switched off.