| 摘要 |
PROBLEM TO BE SOLVED: To provide a control method for reducing the distortion of an input current to stabilize this input current during oscillation of a magnetron in the high-frequency heating power supply for driving the magnetron. SOLUTION: This high-frequency heating power supply has a structure such that the on/off duty ratio of each semiconductor switch element is set to 50% and the role of these elements are interchanged smoothly at an area near the polarity changing point, when one semiconductor switching element 12, which executes the voltage charge-up function and inverter function in the switching operations of the first inversely conductible semiconductor switching element 12 and the second inversely conductible semiconductor switching element 13 interchanges it functions to the other semiconductor switching element 13, which executes only the inverter function at the polarity changing point, where the polarity of the commercial power supply 1 changes. With this structure, since the semiconductor switch elements 12, 13 interchange the roles with the timings, where charge or discharge process of the charge-up capacitor 16 or 17 is completed, a stable input current in which the harmonic elements are controlled can be obtained in a high power-factor with less distortion.
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