| 摘要 |
PROBLEM TO BE SOLVED: To reduce output ripples despite a one-converter circuit configuration.SOLUTION: A load drive device 1 includes: a rectification circuit BD1 for full-wave-rectifying an AC voltage to output a rectified voltage; a power factor improvement circuit 2 comprising a first rectifying element D1, a switching element Q1 and a first reactor L1 connected in series and comprising a second rectifying element D2, a third rectifying element D3 and a first smoothing capacitor C1 connected in series between both ends of the first reactor L1, to improve a power factor of the rectified voltage; a DC/DC converter 3 sharing a first series circuit comprising the switching element Q1, the first smoothing capacitor C1, and the third rectifying element D3 with the power factor improvement circuit 2, comprising a fourth rectifying element D4 connected in parallel therewith, and comprising a second reactor L2 and a second smoothing capacitor C2 connected in series, to apply a DC voltage to a load 10 connected in parallel with the second smoothing capacitor C2; and a drive control circuit 4 for controlling on/off the switching element Q1 to synchronize a buck/boost operation by the power factor improvement circuit 2 and a buck operation by the DC/DC converter 3. |
