Method for operating a frequency converter circuit

Abstract

A frequency converter circuit has at least two outputs that are respectively connected to a load, in particular an induction coil. A first output is operated at a first switching frequency and a second output is simultaneously operated at a second switching frequency that is different from the first, in such a way that noise having a frequency generated by the superposition of the first switching frequency and the second switching frequency is produced. The frequency converter circuit is operated in such a way that the frequency of the noise is lower than a first cutoff frequency and/or is higher than a second cutoff frequency.An induction cooking device includes first and second induction heating elements, and a frequency converter circuit including first and second power outputs electrically coupled to the first and second induction heating elements, respectively. The frequency converter circuit generates first and second power output signals with first and second switching frequencies applied to the first and second power outputs, respectively. The second switching frequency is selected to be no greater than a first cut-off frequency and no less than a second cut-off frequency (e.g., higher than the first cut-off frequency). The induction cooking device regulates electrical power applied to the first and/or second outputs by adjusting the switching frequency and/or a duration during which at least one of the first and second switching frequencies are applied in a repeating cycle during which the electrical power applied to the first and/or second outputs.