| 摘要 |
PURPOSE:To adjust a luminous quantity from an optical transmission unit automatically in the optical communication. CONSTITUTION:An optical signal 11 outputted from a voltage-to-optical transducer circuit 1 is dispersed by an optical prism 2 to produce a light 13 for luminous quantity measurement in addition to a communication light 12 and the light 13 for luminous quantity measurement is transduced to a voltage by an optical- to-voltage transducer solar cell 3. A transduced voltage V11 is compared with a reference voltage V1, V2 generated by a reference voltage circuit 14 at a comparator 5, 6 and a switch 7 is thrown depending on outputs VO1, VO2 of the comparators 5, 6 to select automatically a current limit resistor 8 thereby adjusting the luminous quantity of the voltage-to-optical transducer circuit 1 automatically. |
