ABONNENTANSLUTNINGSKRETS INNEFATTANDE EN SYMMETRISK EFFEKTFORSTERKARE FOR MATNING AV EN ABONNENTLEDNING

摘要

A subscriber's connecting network comprising a symmetrical power amplifier which is formed by two pairs of complementary transistors. Resistors having the same values are arranged in collector circuits of the transistors of the symmetrical amplifier for limiting the current in the subscriber's line. In addition, means are present for making the base voltage dependent on the collector voltage of this transistor so that a predetermined voltage is present between these two electrodes in the normal direction of operation. Finally a by-pass capacitor for the speech currents in the subscriber's line is arranged between two input terminals of the symmetrical amplifier. The invention is particularly suitable for a network in which binary signals are used for the generation of ringing signals and metering signals in the subscriber's line.