Patent ID: 7656691

Claim:
Apparatus for converting power from a power input to an output power supply, the apparatus comprising: a resonance converter , the resonance converter comprising at least two serial coupled semiconductor switches, wherein: the semiconductor switches comprise at least one common output terminal, the one common output terminal is connected to at least one first coil, the first coil is connected to a second coil, the second coil is connected to a first capacitor, the second coil is part of a transformer, the transformer comprises a third coil connected to rectifier means, the rectifier means has its output connected to output terminals, a first feedback circuit connects one of the output terminals to an error amplifier, the error amplifier is connected to a first input terminal of a control circuit, the control circuit comprises an output that is connected over driver means to an input of the semiconductor switches, a second feedback circuit, the second feedback circuit comprises at least one second capacitor connected to a second input terminal of the control circuit, the second feedback circuit is connected to a capacitive divider including a third capacitor and a fourth capacitor in series, the fourth capacitor is connected to common ground and the third capacitor is connected to the first capacitor, wherein the midpoint of the capacitive divider is connected to a further capacitor and resistor in parallel connected to the second feedback circuit, and the second feedback circuit transmits a feedback signal from the first capacitor, the first capacitor is serially connected to the second coil and to ground, the second capacitor controls a switching frequency of the semiconductor switches, the second feedback circuit transmits the feedback signal depending on an actual change of charge of the first capacitor in each half period of switching of the first capacitor, and the feedback signal linearizes the influence of the first feedback circuit.