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 101
ight, when filled, carries four shelves, each having a capacity of 50lineswitches. These lineswitches may be divided into four sections SI A UTOMA TIC TELEPHONY each employing a master switch, or they may be divided into eight sec-tions, each having a master switch. In the latter event, one… … Fig. 76.—Secondary lineswiteh, Keith. As stated in the chapter on Trunking, when the secondary line-switches are inserted between the primary lineswitches and the firstselectors, they are used to reduce the number of first selectors required,by placing the first selector switches in groups of 100…
Telephone
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