| 摘要 |
PROBLEM TO BE SOLVED: To provide a bridgeless power-supply circuit that allows reducing power loss and simplifying its configuration by reducing the number of components as compared with conventional examples.SOLUTION: A connection point of one terminals of first and second switching elements Q51 and Q52 is connected to one terminal of a smoothing capacitor C51. A first unidirectional element D51 is connected between the other terminal of the smoothing capacitor C51 and the other terminal of the first switching element Q51, and a second unidirectional element D52 is connected between the other terminal of the smoothing capacitor C51 and the other terminal of the second switching element Q52. An inductor L51 and a series circuit of the first and second switching elements Q51 and Q52 connected in series to the inductor L51 are connected between input terminals T1p and T1n of an AC power supply. A control circuit 51 causes the second switching element Q52 to stay in an on state and causes the first switching element Q51 to switch during a first half cycle of an AC power-supply voltage, and causes the first switching element Q51 to stay in an on state and causes the second switching element Q52 to switch during a second half cycle. |
