Patent ID: 6914394

Claim:
A supply circuit having a switching transistor (T 1 ), and a forcing circuit (ZS) for driving a control input of the switching transistor (T 1 ), characterized in that an oscillator circuit (OS) which is connected to the control input is provided and is configured in such a way that a startup operation of the supply circuit firstly carries out an oscillation which is independent of the forcing circuit (ZS) and in doing so actuates the control input of the switching transistor (T 1 ), and the supply circuit is configured in such a way that the forcing circuit (ZS) is supplied, as a result of the driving of the control input by the oscillator circuit (OS), by a supply current produced by the supply circuit, and subsequently performs the driving of the control input of the switching transistor (T 1 ), wherein the oscillator circuit (OS) is an amplifier circuit with a feedback (C 71 ) which has an input (E) which is connected to an output (A 1 ) of the forcing circuit (ZS), and an output (A 2 ) which is connected to the control input of the switching transistor (T 1 ), and serves as an amplifier for the output (A 1 ) of the forcing circuit (ZS) when the control input of the switching transistor (T 1 ) is driven by the forcing circuit (ZS).