| 摘要 |
PURPOSE:To attain easy retrieval of failed position by conducting entirely the signal injection and detection to a high voltage section and the operating power for circuits or the like by means of an optical signal and light energy to inject easily a signal in an underwater cable and detect the signal. CONSTITUTION:An AC current flowing to a conductor 3 is detected as a voltage between both terminals of a resistor 41, amplified by an amplifier circuit 42 and an electric signal is converted into a light signal at an electrooptic converting circuit 43. This optical output is led externally from an underwater cable anchor frame 1 by an optical fiber 44 and measured by an optical level meter 7. On the other hand, an optical fiber 51 for light signal transmission leads an output of an optical oscillator 8 into photoelectric converting circuit 52, where the signal is converted into an electric signal, this converted output is amplified by an amplifier 53 and injected to the conductor 3 by a signal injection circuit 54. |
