Circuitry for superimposing small, low energy signals and large, essentially higher energy signals

Abstract From the Canadian patent

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 receiving circuitry or with a high energy alternating Signal for example a call al-, ternating voltage for signalling. In Ihis circuitry is provided an operation amplifier (I). One pole of the source that supplies the small signal is connected to one input of said operation amplifier whose operational voltage inputs arc connected to a voltage supply source. In order to allow low energy, weak signal, such as speech signals and, high energy signals and direct voltages to be transmitted by …