| 摘要 |
PROBLEM TO BE SOLVED: To reduce a higher harmonic distortion of the power supply generated in a phase in the vicinity of 0°and 180°in which an instant voltage of a commercial power supply becomes the lowest regarding a high frequency heating power supply device to drive a magnetron such as a microwave oven. SOLUTION: In giving a signal to drive a first semiconductor switching element 3 and a second semiconductor switching element 4, and in the phase in the vicinity of 0°and 180°in which the instant voltage of the commercial power supply becomes the lowest so that a switching frequency in the vicinity of a border between a period in which the lowest switching frequency is limited by f1 and a period in which it is released is changed smoothly, that is, by eliminating a sudden change of the switching frequency, thereby generation of the higher harmonic distortion of the power supply is suppressed. COPYRIGHT: (C)2006,JPO&NCIPI
|
