Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems (1921)
Smith, Arthur Bessey, b. 1875, Campbell, Wilson Lee · New York : McGraw-Hill · leaf 315
tch-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… … 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…
Telephone
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