EINRICHTUNG UND VERFAHREN ZUR DURCHFUEHRUNG VON TELEFONGESPRAECHEN ZWISCHEN DREI UND MEHR TEILNEHMERSTELLEN.

摘要

The hybrids (G1-Gn) are connected on the sides remote from the subscriber lines (a/b) with balancing circuits (NBl-n) and with go and return paths including variable amplifiers (V1p-n) and (V2p-n) connected to low frequency connections (Pl-n). Circuits (A,st) and switches (S1,S2 etc.) inject a test signal through the hybrids for measurement of the signal levels. The central control (St) adjusts each respective hybrid balancing circuit in dependence on the impedance shown to the test signal and simultaneously to adjust the amplifiers in dependence on the impedance as well as to control speech direction and speech signal level.