In a system, an output voltage of a power generator is input to a filter circuit. The filter circuit includes a first capacitor having opposing first and second electrodes, a second capacitor having opposing third and fourth electrodes, a first switch electrically connected to be series with the third electrode of the second capacitor, and a second switch electrically connected to be series with the fourth electrode of the second capacitor. A series circuit of series-connected first switch, the second capacitor, and the second switch is electrically connected with the first capacitor in parallel thereto. A control circuit is electrically connected to the first and second switches of the filter circuit. The control unit is configured to control the first and second switches to be substantially simultaneously on and off to thereby cause the filter circuit to filter the frequency components from the output voltage.