PURPOSE: To detect a fault of a light signal output including an electrooptic converter, by branching and converting part of a light signal into an electric signal, and then integrating and comparing it with a prescribed value.
CONSTITUTION: An optical branching filter 2 extracts and inputs part of a light signal 102, obtained through the conversion of an electrooptic converter 1, to a photoelectric converter 3. An electric signal 105 obtained by the photoelectric converter 3 is integrated by an integrator 4 and then compared with a prescribed value 109 by a comparator 5. The comparator 5 sends out an error signal by setting a flip-flop 6 when a integral output 106 exceeds the prescribed value 109, namely, when the light signal has an error, and when an error occurs to the electrooptic converter 1.
WATANABE AKIRA
TAKIZAWA MINORU
SASAKI TAKAYOSHI
NIPPON ELECTRIC CO
| JPS5769228A | 1982-04-27 | |||
| JPS55110086A | 1980-08-25 | |||
| JPS55152434A | 1980-11-27 | |||
| JPS56119547A | 1981-09-19 |