Patent ID: 8330391

Claim:
A supply circuit for supplying an output signal to a load, the supply circuit comprising: a first circuit for converting an input signal having an input voltage level into a pulse signal comprising a series of pulses having a pulse frequency, and wherein the first circuit comprises transistors, a second circuit for receiving the pulse signal and for supplying the output signal to the load, wherein the second circuit comprises a resonance circuit, and a third circuit for controlling the first circuit, wherein the third circuit comprises a generator for generating a control signal for controlling the transistors for reducing a dependency between the input signal and the output signal, wherein the third circuit includes an input for receiving the input signal and includes an output for supplying the control signal in dependence of the input signal and independently from the output signal, and wherein the generator generates the control signal such that a product of the input voltage level and the frequency of the pulse signal is kept constant.