AC-DC converter

摘要

An AC-DC converter includes an adjusting unit 13 which operates to zero the difference between a DC output voltage instruction value and a DC output voltage detection value; and a modulator 16 which compares a carrier wave based on an output signal of the adjusting unit 13 with a modulating wave to output drive pulses, a switching element 3 is turned on and off with the drive pulses to provide a DC output voltage which is higher than a full-wave rectification voltage of an AC input voltage. In order to obtain the carrier wave, the AC-DC comprises further includes an AC input voltage polarity detector 7, a PLL circuit 11, and a multiplier 14 for multiplying the sine wave by an output signal of the adjusting unit 13.