| 摘要 |
PURPOSE:To ensure safety by stopping the power supply to a maximized circuit block being not in use at loopback in a network system of loop shape so as to reduce the power consumption at a repeater. CONSTITUTION:If a fault takes place at an optical fiber A, an output of the 1st comparator 14 goes to '0' level, and if a fault takes place in the optical fiber B, an output of the 2nd comparator 15 goes to '0' level and they are at '1' level respectively at normal state. The level of output terminal 22, 23 of the discrimination circuit 16 goes to '1' level when the output of comparators 14, 15 goes to '1' level, and the output terminal 2 goes to '0' level and the terminal 23 goes to '1' level when the output of the comparator 14 is at '1' level and the output of the comparator 15 is at '0' level, and when the output of the comparator 14 is at '0' level and the output of the comparator 15 is at '1' level, the output terminal 11 goes to '1' level and the terminal 23 goes to '0' level. When the output terminal 22 is at '1' level, the 1st stop circuit is turned on and then the output terminal 23 is at '1' level, the 2nd stop circuit is turned on to control the power to the supplied circuit block. |
