To produce a plurality of voltages, while suppressing the noise by providing a switching frequency control means, a switching waveform dulling means and a peak resonance means and regulating the output voltages therefrom, through series regulators.

An oscillator 10 constitutes a switching frequency control means 52, resistors 12, 13 constitute a waveform dulling means 53, and a capacitor 4 and inductance coils 14, 15 constitute a peak resonance means 54. The switching frequency control means 52 controls the switching frequency of a pulse width modulation means 51, the waveform dulling means 53 dulls the rising and falling of switching waveform, the peak resonance means 54 resonates the rising part of switching waveform, and a plurality of series regulators 17 outputs a secondary voltage, while regulating. According to the circuitry, a plurality of voltages can be outputted, while lowering the noise level.