Patent ID: 8411476

Claim:
Apparatus for converting power from a power input to an output power supply, the apparatus comprising: a resonance converter, the resonance converter having at least two serially coupled semiconductor switches, wherein the semiconductor switches have at least one common output terminal which is connected to at least one first coil, wherein the first coil (L) and a first capacitor (Cp), and a second coil (Lprim) are serial connected to each other in an arbitrary order, wherein the second coil (Lprim) is part of a transformer (T 1 ), wherein the transformer (T 1 ) has a third coil connected to rectifier means, wherein the rectifier means has an output connected to output terminals, wherein a first feedback circuit connects one of the output terminals of the rectifier means to an error amplifier, wherein the error amplifier is connected to a first input at a control circuit, wherein the control circuit has an output that is connected over driver means to the input of the semiconductor switches, wherein a second feedback circuit has at least one first resistor (Rsense) that is connected to the second coil (Lprim) and to ground, connects a line between the first resistor (Rsense) and the second coil (Lprim), and has an inverting integrator with an output that is connected through a second capacitor (Cf) to a second input (Pin- 3 ) of the control circuit, wherein the first resistor (Rsense) constitutes the means for sensing a first current (Iresonans) which current, via the inverting integrator, becomes a controlling charge signal, which signal is output from the inverting integrator.