| 摘要 |
PURPOSE:To switch an electric signal line simply with an optical signal independently of noise by means of an optical connector on market when an electric noise is generated or it is possible that a noise is generated by detecting a specific signal included in an optical signal or the optical signal itself at the reception side to switch the input to a receiver from the electric signal position to the optical signal position. CONSTITUTION:A specific signal such as a prescribed period of synchronizing signal or a clock signal included in an optical signal transmitted from an optical cable 1 is extracted by a filter 8. A level detector 9 is provided to prevent malfunction due to noise, and when an output of the filter 8 reaches a prescribed level or over, the level detector 9 generates an output to excite a relay to switch a moving contact 5 to a fixed contact 7 at the optical signal side. When a specific frequency signal is not included in the optical signal, the specific signal has only to be superimposed on the optical signal at the transmission side. Further, the transmission of the optical signal is started from the transmission side at switching to detect the optical signal itself thereby operating the switch. In this case, no filter 8 is required. |
