US Patent 7138731 Switching converter having a controllable load element

Switching converter to convert an input direct current (UE) into at least one output direct current (UA), wherein an internal auxiliary voltage (UH1, UH2) is derived from at least one auxiliary winding (WH1, WH2) of a transformer (Tr), a controllable load element (BAL) is provided for the output voltage, and a stop signal (ss) can be fed to turn the output voltage of the switching converter ON/OFF, which is used to connect the load element (BAL) to the output direct current to such an extent that a short-circuit-like condition is produced, in which the output voltage (Ua) is adequately close to null, but the at least one auxiliary voltage (UH1, UH2) is adequately high to supply the units associated therewith.