| 摘要 |
<p>A power feed line switching circuit for a submarine branching unit has first, second and third electrical paths connected in a Y-shaped connection, and first, second and third terminals connected respectively thereto. The power feed line switching circuit also has first, second and third relays each including a drive unit inserted in the first, second and third terminals and a switching unit for disconnecting the corresponding terminal and connecting the terminal to the ground, respectively. These relays are used to control the connections between the terminals and electrical paths, for establishing a one-end power feed line or a both-end power feed line to maintain power feed for repeaters and the submarine branching unit by the plurality of relays, even though a fault is caused in the optical marine cables for cable landing stations.</p> |
