GB337102A - Improvements in telegraphic systems - Google Patents

Abstract

337,102. Lorenz Akt.-Ges., C. Feb. 28, 1929, [Convention date]. Repeating systems using contact-making apparatus; controlling direction of simpler traffic.-At a terminal station or relay station the outgoing line is automatically disconnected from the earthed receiver or input relay and connected to the transmitting or sending-on circuit when signal-transmission begins, and the connection is reversed when signalling ceases. In an exchange switchboard and transmitter, impulses received by the input relay ER from the incoming line L1 are relayed through the armature er, jack Kl, plug and cord so as to set, up a potential-drop in the resistance Wi and thus affect the sending-on relay SR whose armature sr sends on the signals through the armature ur to the outgoing line L2. The armature ur is kept closed, during transmission from L1 to L2, by the reversing relay UR which, like sending-on relay SR and auxiliary relay HR, is polarized and is connected in a circuit comprising the condenser C. To hold on the connection ur the slow releases relay VR is provided; this relay is cut in by the armature hr at the first excitation of the relay HR, and the hold-on winding II of relay UR is thus energized through armature vr1. At the end of the message the armature vr, is released first and returns to the position shown, whereupon a reversed current from the batterv E flows in the coil II, so as to confirm the release of the line contact ur. The contact vr2 is only subsequently released. The connections are symmetrical so that signals may be passed from line L2, to line L1, in a similar manner. At a termnial station (Fig. 1, not shown) the winding ER operates, a receiving instrument for incoming messages, and a similar winding in series with the transmitter contact sr<1> operates the same receiver so as to record outgoing messages.