Abstract: For protection against electromagnetic interference in an apparatus which has a loaded device that can be fed from at least two separate energy sources, an EMC filter is employed with a common-mode inductor arranged to pass through the supply and return line paths which are provided between the energy sources and the load device. This ensures that transition to magnetic saturation is essentially completely precluded even in the case of redundant power supplies to which respectively associated line paths can be routed to and from the load device and, in consequence, with the current being shared differently, since the sum of all the currents passing through the common-mode inductor is approximately zero.

Abstract: A block encoded main signal and a balanced block encoded auxiliary signal are combined on a transmission path. The combined signal includes at least one block of encoded main channel signal alternating with one bit of the auxiliary channel signal. The block code for the auxiliary channel is simpler than the block code for the main channel.