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 transmitting speech signals with a remote supply direct signal for a receiving circuit or with a high energy alternating signal, for example a call alternating voltage for signaling. The circuitry includes an operational amplifier (1), having one input connected to a pole of a source supplying the small signal and operational voltage inputs being connected to a voltage supply source. In order to allow low energy, weak signals, such as speech signals, and high energy signals and direct voltages to be transmitted by such a circuitry over a subscriber line by means of simple components, the second pole of the small signal source (2) is connected to the second input of the operational amplifier (1) and one pole of a higher energy signal supply source (3) is connected to one pole of the voltage supply source (V).