| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high-frequency power supply unit capable of enhancing detection accuracy when detecting the occurrence of arc which occurs in a load. <P>SOLUTION: The high-frequency power supply unit 1 comprises an oscillating section 14 supplying a high-frequency electric power with respect to a load L and an amplifying section 15, a power detecting section 16 detecting the high-frequency power made incident on the load L and the high-frequency power reflected from the load L, a reflection coefficient calculation section 17 calculating the reflection coefficient based on the incident electric power to the load L and the reflected electric power from the load L each detected by the power detecting section 16, an arc detecting section 18 judging whether the value of the reflection coefficient calculated by the reflection coefficient calculation section 17 fluctuates more than the judging reference width W which is preset within a predetermined time and detecting the occurrence of the arc in the load L based on the judged result, and a reference width setting section 18 varying the judging reference width W corresponding to the value of the reflected coefficient when whether the value of the reflection coefficient calculated by the reflection coefficient calculation section 17 is judged to fluctuate over the judging reference width W within a judging time T. <P>COPYRIGHT: (C)2007,JPO&INPIT |
