Abstract: A filter circuit is provided in the secondary of a power transformer following a rectifier and is composed of two chokes respectively arranged in the series arms of the lines leading to two output terminals, and at least one shunt capacitor. Each of the chokes is composed of a winding fashioned as a strip-shaped interconnect, whereby both windings are conducted through a common magnetic core in the same winding sense.

Abstract: The invention relates to a fault recognition circuit for at least two power supplies feeding in parallel a user at an output side. The power supplies each have an electronic switch, a power transformer and a rectifier portion with a following filter element. In order to achieve short repair times, the respective down power supply is immediately identified after the outage of one of the parallel power supplies. For this purpose, a current transformer is provided which lies between the electronic switch and the power transformer. The load voltage of the current transformer is supplied to first a rectifier unit and the ac voltage component of the unfiltered dc voltage at the rectifier portion of the power pack units is supplied via a high pass filter to a second rectifier unit. The outputs of the rectifier units are connected to inputs of first and second comparators, and the other inputs of the comparators are connected with comparison voltages.