| 摘要 |
PROBLEM TO BE SOLVED: To reduce output ripples although a load drive device includes one converter circuit structure.SOLUTION: A load drive device 1 includes a rectifying circuit BD1 for outputting a rectified voltage obtained by full-wave rectification of an AC voltage, a power factor improving circuit 2 in which a first reactor L1, a first rectifying element D1, and a switching element Q1 are serially connected between the positive electrode and the negative electrode of the rectifying circuit BD1, and a second rectifying element D2 and a first smoothing capacitor C1 are serially connected at both ends of the switching element Q1 to improve the power factor of the rectified voltage, a DC/DC converter 3 in which the switching element Q1, the second rectifying element D2 and the first smoothing capacitor C1 are communized, and a second reactor L2 and a second smoothing capacitor C2 are serially connected at both ends of the second rectifying element D2 to apply a DC voltage to a load 10 parallel connected to the second smoothing capacitor C2, and a drive control circuit 4 for controlling ON/OFF of the switching element Q1 to synchronously perform voltage step-up by the power factor improving circuit 2 and voltage step-down by the DC/DC converter 3. |
