Patent ID: 8207683

Claim:
A buck converter for providing a current for at least one light emitting diode, the buck converter comprising: an input having a first and a second input connection for connection of a DC voltage source; an output having a first and a second output connection for connection of the at least one light emitting diode; and a Buck diode, a Buck inductor and a Buck main switch which has a control electrode, a working electrode and a reference electrode; wherein the Buck diode and the Buck main switch are coupled in series between the first and the second input connection, wherein the connecting point between the Buck diode and the Buck main switch is coupled to the second output connection; wherein the first connection of the Buck inductor is coupled to the first input connection and the second connection of the Buck inductor is coupled to the first output connection; wherein the Buck converter furthermore comprises: a first auxiliary winding which is coupled to the Buck inductor and has a first connection which is coupled to the second input connection and a second connection which is coupled to the control electrode of the Buck main switch, wherein the first auxiliary winding is coupled to the Buck inductor such that, when current is flowing through the Buck main switch, a current is provided through the first auxiliary winding to the control electrode of the Buck main switch.