| 摘要 |
PURPOSE:To attain accurate input power monitoring independently of the temperature change in an optical reproduction repeater by using a temperature characteristic of a terminal voltage of a Zener diode of a power supply circuit to apply temperature compensation for an input power monitor voltage. CONSTITUTION:When an ambient temperature of an optical reproduction repeater rises by DELTAT, a terminal voltage of a Zener diode 12 of a POW 6 changes. The change in the terminal voltage and a photodetector control voltage V1+DELTAV are inputted to a CPS 7, where they are calculated and a temperature compensation voltage DELTAV is outputted. The temperature compensation voltage DELTAV inputted to other input terminal of an OP 8 is subtracted from the photodetector control voltage V1+DELTAV inputted to one input terminal at the OP 8 to restore the input power monitor voltage outputted from the OP 8 is restored to the voltage V1. When the photodetection power is P1, the input power monitor voltage is V1 independently of the temperature. |
