A power-supply circuit having a switching regulator (10) and at least one additional circuit (14, 14') whose two respective outputs (11, 17) are guided together to a common or joint output (18) by diodes (D3, D3'; D4). The additional circuit (14, 14') produces, from an alternating quantity (15) occurring inside the switching regulator (10), a second output voltage (U+, U'+) that is in a second output-voltage range and is more positive with respect to the first output voltage (U-) that is made available at the first output (11) of the switching regulator (10) and is in a first output-voltage range. A gas-discharge lamp, for example, is provided as the load (L) between the first and second outputs. The division of the voltage ranges to be made available for the load (L) into at least two partial ranges permits a high effectiveness of the current-supply circuit of the invention.