Single phase AC-DC converter having a power factor control function

A single-phase AC-DC converter comprising:

• a PFC power supply section, where a rectified current obtained by rectifying an electric current from an AC supply is switched;
• a DC-DC power supply section, where a direct current obtained by rectifying and smoothing an electric current from an AC supply is switched;
• a first switching means for conducting a switching operation in said PFC power supply section;
• a second switching means for conducting a switching operation in said DC-DC power supply section;
• a drive pulse generating circuit for generating first drive pulses for driving said first switching means and second drive pulses for driving said second switching means;
• and a servo loop for controlling said drive pulse generating circuit;
• wherein said servo loop is constituted of only one serve loop;
• and wherein said converter comprises a duty ratio controlling means for making a duty ratio of said drive pulses for driving said first switching means and a duty ratio of said drive pulses for driving said second switching means different from each other in a linked manner.