Patent ID: 7366410

Claim:
A signal relay apparatus in an optical communication system in which a plurality of electronic equipments are connected to the signal relay apparatus and to one another in a ring-like form, and each of the electronic equipment relays an optical signal using an optical transmission line, comprising: a plurality of photoelectric converting units which are provided in correspondence with the electronic equipments, each of which detects optical signals, converts an optical signal received from the corresponding electronic equipment into an electric signal, outputs the electric signal to another photoelectric converting unit, converts an electric signal input from other photoelectric converting unit into an optical signal and outputs the optical signal to the corresponding electronic equipment; a plurality of switch circuits which are provided in electric signal input and output ends of each of the photoelectric converting unit, and which are opened and closed to bypass an electric signal from adjacent photoelectric converting unit; and power source supply control apparatuses which are provided in correspondence with the photoelectric converting units, and which supply power sources to the electronic equipments which are connected to the photoelectric converting units, wherein when the electronic equipment connected to each of the photoelectric converting unit is not used, each of the switch circuit bypasses the electric signal from the adjacent photoelectric converting unit, and each of the power source supply control apparatus stops the supply of the power source to the electronic equipment.