PURPOSE: To eliminate adverse effect on a change in characteristic of a component requirement, by using an optical fiber as transmission part to turn a signal to an optical signal converted into digital.
CONSTITUTION: An invading surge current is converted into a digital value with an A/D converter 3 and, further, into an optical signal with an E/O converter 4. The optical signal is transmitted to an O/E converter 6 with an optical fiber 5 to be converted into an electrical signal, which is outputted with an output device 9 to observe a surge. A plurality, n+1, of optical fibers 5 as transmission part are connected to the E/O converter 4. Thus, the E/O converter 4, the optical fibers 5 and the like are given a sufficient allowance as digital criterion, thereby eliminating the lowering of a measuring accuracy regardless of specified changes caused by temperature change or secular change.
SUGA MASAHIRO
ANDO AKITOSHI
| JPS54107780A | 1979-08-23 | |||
| JPS5533606A | 1980-03-08 | |||
| JPS4932678A | 1974-03-25 |