Patent ID: 8446744

Claim:
A method for controlling a switching device, the method comprising the acts of: providing a switching voltage by a resonant circuit for generating a resonant current in order to provide a required output power at an output of a resonant power converter; and providing the required output power at the output of the resonant power converter by using a first control mode and a second control mode in an alternating sequence in order to provide at least three power levels including a zero power lever, a first power level and a second power level, wherein the first power level s higher than the second power level, wherein the first control mode is a soft switching control mode with respect to the switching voltage and to the resonant current, wherein the second control mode is a non-soft switching control mode with respect to the switching voltage and to the resonant current, wherein the act of providing the required output power initially provides pulses between the zero power level and the first power level so that the required output power is between the zero power level and the second power level, and subsequently provides further pulses between the second power level and the first power level so that the required output power is between the second power level and the first power level.