| 摘要 |
<p>PURPOSE:To make it possible to measure not only a commercial frequency, but also a high-frequency component contained in a surge, by constructing a receiving part so that it detects a low-frequency component and the high-frequency component separately. CONSTITUTION:A light transformer comprises an electro-optical transducer 1 converting a voltage-current to be measured into a light signal, a wide-band amplifier 4 converting the light signal into an electric signal, a low-frequency amplifier 5 amplifying only a low-frequency component of signals therefrom, and a high-frequency amplifier 6 amplifying only a high-frequency component thereof. After an output light 3 of the device 1 is amplified by the amplifier 4, the low-frequency and high-frequency components are separated and a stationary voltage-current component and a temporary signal component such as a lighting-switching surge are distinguished from each other and measured. On the occasion, the amplifier 6 does not need to have so high a function as that for the low-frequency component. According to this constitution, an invasion from outside and a surge voltage generated inside can be measured by a compact arrangement for a long time, while a highly-precise function of measurement for a commercial frequency is maintained.</p> |
