ARRANGEMENT FOR APPLYING SIGNALS TO A TELEPHONE LINE

摘要

25.1.1980 1 PHN 9466 " ". Arrangement for applying signals to a telephone line. Arrangement for applying signals to a twowire telephone line, comprising two line control circuits each comprising a fed-back amplifier circuit. According to the invention the amplifier circuits are constructed from an input stage constituted by an operational amplifier, a transistor arranged as a voltage amplifier (intermediate stage), and a power output stage which is in the form of a push pull amplifier. The line control circuits can either receive the control signals with an opposite polarity or they can both receive the same control signal, one line control circuit being used as an inverting and the other as a non-inverting amplifier.