Hybrid circuit with active components - has comparator to which two and four wire input voltages are applied, and has output voltage equivalent to that of four wire output

摘要

The circuit is provided at the junction between a two-wire and a four-wire line at the interface between transmission and switching systems. The circuit has a transformer isolating the two-wire terminals, and four-wire inputs and outputs. Input voltage (Ue) at the circuit (1) four-wire input (10) is connected through an amplifier (11) to the two-wire line (2) terminal (21), and to the input (31) of a comparator (3). This input voltage (Ue) is also applied through a balancing network (12) and an amplifier (13) to the comparator (3) other input (32). The comparator output (33) voltage (Ua) is the four-wire line output voltage.