CIRCUITRY FOR SUPERIMPOSING SMALL, LOW ENERGY SIGNALS AND LARGE, ESSENTIALLY HIGHER ENERGY SIGNALS

摘要

A circuitry is disclosed for superimposing small, low energy (2)and large substantially higher energy (3) signals, in particular for trans-mitting speech signals with a remote supply direct signal for a receivingcircuitry or with a high energy alternating Signal, for example a call al-ternating voltage for signalling. In Ihis circuitry is provided an opera-tion amplifier (I). One pole of the source that supplies the small signalis connected to one input of said operation amplifier whose operation-al voltage inputs arc connected to a voltage supply source. In order to allowlow energy, weak signal, such as speech signals, andhigh energy signals and direct voltages to be transmitted by such circuitryover a subscriber line by means of simple components,the second pole of the small signal source (2) is linked to the second inputof the operation amplifier (I) and one pole of a higherenergy signal supply source (3) is linked to one pole of the voltage supplysource (V).