| 摘要 |
PURPOSE:To adjust a level automatically without minding a fixed loss of a transformer and to implement almost all control digitally. CONSTITUTION:An analog input signal is amplified by a sender side analog amplifier 22, converted into a digital signal by an A/D converter 25, sent to an opposite station, a digital input signal from the opposite station is converted into an analog signal at a D/A converter 28 and it is amplified by a receiver side analog amplifier 27 in the system, which is provided with a digital pattern generator 31, and a peak detector 24 and a gain control section 21 control digitally the gain of the said sender side analog amplifier 23 and the receiver side analog amplifier 27. Thus, no manual work is required for fine-adjustment of the level and the level is accurately adjusted. |
