| 摘要 |
PROBLEM TO BE SOLVED: To suppress common-mode noises by means of only one magnetic material, by so providing a magnetic circuit common to the connection paths of an uninterruptible power supply unit with its AC power supply and its load as to insert the magnetic circuit into the connection paths. SOLUTION: In addition to a rectifier 12, a battery 13, and an inverter 14, an uninterruptible power supply unit 20 has a common-mode choke 21 comprising windings 21a, 21b and such a magnetic material 21c common to the windings 21a, 21b as a ferrite core. Further, connecting an AC power supply 1 and a load 2 with the interruptible power supply unit 20 via the windings 21a, 21b, the polarities as shown in the figure are given respectively to the windings 21a, 21b to suppress common-mode noises generated in the uninterruptible power supply unit 20 between it and the earth from leaking to the external. As a result, the common-mode noises accompanied by the switching operations of the uninterruptible power supply unit 20 can be suppressed. |
