| 摘要 |
PURPOSE:To minimize occurrence positions of faults and to facilitate search for fault point by providing a branching device in the sea and grounding a feeder from a repeater in the branching device in the sea. CONSTITUTION:Fed currents IO from constant current sources 30 in terrestrial stations A, B, and C are supplied in series respectively and grounded through a diode 50 to form a grounding return circuit. Even if a grounding fault occurs between the terrestrial station C and branching device 20, a repeater 6 is fed from the terrestrial stations A and B, so the transmission line between the stations A and B is not influenced at all. Further, even after the feeding to the station B is stopped, the feeding from the terrestrial station A to a feeder 10 is carried out by inverting the polarity of the constant current sources 30 with switches 40 because a diode bridge is used for a feeding part. Therefore, the transmission lines between the stations A and B, and each repeater and the branching device are monitored separately. |
