. Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems . ng her ringing key, which shethen restores to normal. When the pay-station party responds, current 19 290 AI TOM A TIC TELElIION Y flows from earth through one winding of the polarized relay and thesubscribers loop, back through the other winding of the polarized relayto negative battery. The polarized relay swings its armature awayfrom normal and in doing so breaks the circuit through the supervisorylamp of the cord. When the subscriber finishes conversation and places his receiver onthe switch-hook, the
. Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems . ng her ringing key, which shethen restores to normal. When the pay-station party responds, current 19 290 AI TOM A TIC TELElIION Y flows from earth through one winding of the polarized relay and thesubscribers loop, back through the other winding of the polarized relayto negative battery. The polarized relay swings its armature awayfrom normal and in doing so breaks the circuit through the supervisorylamp of the cord. When the subscriber finishes conversation and places his receiver onthe switch-hook, the armature of the polarized relay returns to normalposition and the supervisory lamp lights, giving the operator the requireddisconnect signal. Toll Service Trunk Circuits.—In modern automatic service it iscustomary to divide the connectors which serve a certain group of sub-scribers into two classes, regular connectors and combination toll andregular connectors. The regular connectors are seizeable only by sub-scribers in the ordinary course of their call. The combination connectors. Fig. 246.—A pay-station line equipment at its toll-board end. are also seizeable by subscribers, but the trunking arrangement is suchthat no combination connector of a group will be seized by a subscriberuntil after all of the regular connectors in the group are in use. Whenthus seized, the combination connectors give a service identical with thatof a regular connector. The trunks to the combination connectors, in addition to appearingin the bank of the regular third selectors, are also multipled to the banksof the toll third selectors. When a toll operator dials a certain numberthe toll third selector will route the call to one of the combination con-nectors serving the group of which that particular number forms a combination connector will now function as a toll connector, theprincipal difference being that the starting of the automatic ringing willnow be under the control of the to
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttelephone, bookyear19
