Abstract: A supply circuit for supplying electronic devices with current or voltage and mountable as a module has input and output connections, a rectifier cirucit, a transformer having a primary winding coupled with the inputs of the supply circuit and a secondary winding coupled with the rectifier circuit and at least one high-capacity capacitor. The capacitor is coupled with an output of the rectifier circuit for smoothing generated direct current or direct voltage. The capacitor has a housing which housesd the capacitor, the rectifier circuit and the transformer in or on the housing. The input and output connections are arranged on the housing so as to be accessible from outside of the housing. At least a parat of the housing consists of a magnetizable material and carries the primary and secondary windings in the manner of a winding body.