| 摘要 |
PROBLEM TO BE SOLVED: To reduce the cost of a power supply and enhance the reliability of its operation. SOLUTION: Components comprising a power circuit are mounted on a single printed board 11. The printed board 11 is housed in a body 13 of a case made of metal. A notch 12 is formed on the printed board 11, and a shielding plate 14 is erected on the body 13 at a position corresponding to the notch 12. Those component, other than a first capacitor C1 comprising a first direct-current power circuit and components, other than a second capacitor C2 comprising a second direct-current power circuit, are mounted on the printed board 11 in a first region 11a which is spatially isolated by the notch 12. A high-frequency circuit for supplying high-frequency power to a load and a drive circuit for driving a first switching element Q1 are mounted on the printed board 11 in a second region 11b. The distance between the first switching element Q1 and the first capacitor C1 is made shorter than the distance between the first switching element Q1 and the second capacitor C2 . |
