Smooth line protection device of single -ended power supply

The utility model relates to a smooth line protection device of single -ended power supply, including near -end station, remote station, the near -end station is including two photoswitches, photoswitch respectively with center computer room's receiving terminal and activestandby line connection, another photoswitch is connected with center computer room's transmitting terminal and activestandby route respectively, the remote station includes two couplers, coupler respectively with the receiving terminal and the activestandby line connection of point of presence, another coupler respectively with the transmitting terminal and the activestandby line connection of point of presence, still including the monitoring light source, monitoring light source loopback between near -end station, remote station and transmission line. Compared with the prior art, the utility model discloses place all passive component in the point of presence side, realized single -ended power supply. Except that accomplishing conventional route switches, still increased LD type monitoring light source, this light source the distal end through the loopback, get into center computer room's receiving terminal, can real -time supervision route operating condition.