Patent ID: 6917185
Filing Date: 2005-07-12
Classification: H02M,Y02B

Abstract:
1. A converter device having an A/D converter unit for converting AC power to DC power and a power factor improving unit for improving a power factor of said A/D converter unit, wherein said power factor improving unit comprises, a photocoupler for converting an AC power-supply waveform given to said A/D converter unit into a digital signal and outputting said digital signal, a computer system for generating full-wave rectification waveform data synchronized with said AC power-supply waveform on the basis of said digital signal, a D/A converter receiving as a reference voltage a voltage error signal based on a voltage error between a predetermined set voltage and an output voltage of said A/D converter unit, for multiplying together said reference voltage and said full-wave rectification waveform data to output a target current value waveform similar to the waveform of an input voltage in said A/D converter unit, and a current control portion for comparing said target current value waveform and a waveform of a current flowing in said A/D converter unit and controlling said current flowing in said A/D converter unit to reduce a current error between the two.