Patent ID: 7248486

Claim:
A switching converter, for use with an input voltage comprising: at least one control switch coupled to at least one primary winding of a transformer, with a control circuit for controlling the switch, to which a regulating signal in the sense of the regulation of at least an output voltage is sent, wherein the power supply of the control circuit is provided via: i) a forward voltage of an auxiliary winding of the transformer, a first rectifier, a capacitor and aseries regulator, or ii) the input voltage, via a current path and a storage capacitor during initialization of the voltage converter, wherein an off-state voltage of the auxiliary winding, which is rectified by means of a second rectifer is provided to the control circuit as an alternative power supply, wherin the rectified off-state voltage of the auxiliary winding is used to supply power to the control circuit during operation as long as the auxiliary winding has at least a predetermined voltage level.