Abstract: A DC/DC converter has a transformer and a switching transistor provided with a discharge circuit and activated by an actuating circuit. The discharge circuit includes a choke in series with two reverse oriented diodes, and a capacitor connected between the junction of the diodes and the collector of the transistor. With this arrangement, the conventional demagnetizing winding of the transformer may be omitted. The duty factor may be chosen very high, to about 0.75, and the actuation of the switching transistor upon occurrence of a maximum negative magnetizing current may lead to a doubling of the usable induction.

Abstract: A charging device for traction batteries of an electric vehicle consists of a converter module with at least two d.c. blocking converters, each including a control power transistor, a cutoff relief circuit, and a power transformer. The secondary winding of the transformer is connected in series with a rectifier diode and a smoothing capacitor is connected in parallel to the series circuit. The parallel-connected secondary sides of the two blocking converters are connected in such a way that the one secondary winding on the one hand is connected to the negative output terminal and on the other hand by way of one rectifier diode to the positive output terminal. Another secondary winding is connected on the one hand to the positive output terminal and, on the other hand, by way of another rectifier diode to the negative output terminal. A relief circuit composed of diodes is provided on the secondary side of the transformer.