Exchange coupling circuit for teleprinters - has RC coupling stage to minimise distortion of transmitted pulse wave forms

摘要

A switching circuit for coupling teleprinters in a subscriber installation to a central exchange uses an RC element between the lines of the subscriber station to minimise the transmission distortion. The subscriber station (Tn) has electromagnets (GM, EM) and a transmitter contact (sk) coupled to a subscriber line (TL). The subscriber switching station (Ts) connects to a known converter stage (US) with a fixed balancing network resistor (Rn). The two wires of the subscriber station are coupled to the switching station (TS) that has a fixed resistance and capacitor with a series variable resistor. The capacitor is most effective with short lines and minimises the smoothing of the flanks of transmitted pulses.