DC POWER-SUPPLY DEVICE AND AIR CONDITIONER USING THE SAME

PROBLEM TO BE SOLVED: To achieve efficiency improvement, power-factor improvement, and resolution of high-frequency problems at a high level.SOLUTION: A DC power-supply device 11A includes: first and second rectifier circuits 17a and 17b converting AC power from an AC power supply 13 into DC power; a reactor 15 connected to the first and second rectifier circuits 17a and 17b; a switching section 19 short-circuiting the AC power supply 13 via the reactor 15; an input-current acquisition section 27 acquiring a current from the AC power supply 13; an input-voltage acquisition section 25 acquiring a voltage across the AC power supply 13; a DC-output-voltage acquisition section 31 acquiring a DC output voltage across the first and second rectifier circuits 17a and 17b; and a switching control section 43 determining a short-circuit time width of the switching section 19 on the basis of a short-circuit timing of the switching section 19, the DC output voltage, the voltage across the AC power supply 13, and information of the current from the AC power supply.