Communications system for transmitting and receiving data and voice signals simultaneously through 2-wire signal lines

摘要

A communications system for transmitting and receiving data and voice signals simultaneously on 2-wire signal lines, which superposes and extracts high frequency modulated data signals using a high frequency transformer which is coupled to the 2-wire signal line. The transformer has two windings which are short-circuited with respect to high frequency components, but which pass low frequency voice signals between the 2-wire signal line and a low frequency hybrid circuit.