Abstract: The invention relates to a first circuit arrangement (E) for supplying variable loads that can be connected to the first circuit arrangement (E) from a first current or voltage source (MV) in a first state of the first circuit arrangement having the following features: the first circuit arrangement (E) has a first terminal and a second terminal for connection to the first current or voltage source (MV) and a third terminal, at least one fourth terminal and at least one fifth terminal for connection to a second current or voltage source (Z); the second terminal is at a reference potential; the first circuit arrangement (E) has at least one eighth terminal for connection to two loads (R2; R3); the first circuit arrangement (E) has controllable switching means for changing over between the first state and a second state; in the first state, the at least one eighth terminal for connection to the two loads (R2, R3) is connected to the first terminal and the third terminal and the fifth terminal are connected to th