| 摘要 |
PROBLEM TO BE SOLVED: To exactly recognize normal and abnormal states of a high frequency amplifier at normal operation. SOLUTION: An operational amplifier 13 takes the difference between an unbalance detecting signal value Vc from an unbalance detecting part 9 of a synthesizer 4, inputted to a positive input terminal, and a power source output signal value Vp from an output detector 12 inputted to a negative input terminal and compares that difference with a set value Vo and when that difference exceeds the set value, an output stop signal is generated. When the difference between an output signal value Vc from the unbalance detector 9 of the synthesizer 4 and the power source output signal value Vp from the output detector 12 is smaller than the setting value Vo, the operational amplifier 13 generates no signal. When the difference between the output signal value Vc from the unbalance detector 9 of the synthesizer 4 and the power source output signal value Vp from the output detector 12 is greater than the set value Vo, the operational amplifier 13 supplies the output stop signal to a high frequency oscillator 1, so that the output of a high frequency power source can be stopped. |
