The invention relates to a combined AC-DC to DC converter. The converter provides the option of coupling to an AC supply source with at least one phase and the further option of coupling to at least one DC supply source. The converter obtains supply from at least one supply source at a time; and the converter contains controllable contact means that are, upon switching between supply sources, capable of connecting and disconnecting the individual supply sources to/from the converter; whereby a pulse signal is generated. The converter contains at least one coil that is in connection with at least one DC output. The proposed converter distinguishes itself over the prior art in that switching between supply sources is accomplished by means of the contact means over a period of time, where the pulse signal is divided into periods; and wherein the periods alternatingly originate from at least one first supply source and at least one second supply source; and wherein the current pulses from the first supply source is regulated in dependence on the current pulses from the second supply source; and wherein the converter contains means for voltage regulating at least one DC output. Hereby a flexible converter is obtained that can obtain supply from an AC supply source and one or more DC supply sources; and wherein switching between a first supply source and a second supply source can be accomplished without supply failures; and wherein, in overload situations, it is possible to draw on two or more supply sources.