| 摘要 |
PURPOSE:To omit the control line and make the diameter of the cable small to reduce electric power supply, by performing the open loop control of an electric power transmission means by the incoming intensity of the photosignal. CONSTITUTION:Electric power is supplied to stabilizing voltage equipment 203 and light modulator bias current control equipment 204 from variable output power control unit 217 through power source lines 228 and 229. Stabilizing voltage equipment 203 gives a fixed voltage to signal generator 202. The signal from signal generator 202 and the signal from light modulator bias current control equipment 204 are given to electric signal-photosignal converter 205 and are converted to a photosignal and are transmitted to photosignal-electric signal converter 213 through optical fiber cable 226. The electric signal obtained by photosignal-electric signal converter 213 is transmitted to receiving signal processing unit 214 and bias light quantity detector 215. The voltage obtained by bias light quantity detector 215 is compared with the reference voltage to control the output of variable output power control unit 217. |
