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 102
2000) access to a group of 100first selectors. The drawing in Fig. 77 shows the number of primary lineswitches, thenumber of primary lineswiteh groups, the number of trunks from primary AUTOMATIC ELECTRIC COMPANYS APPARATUS 85 lineswitches to secondary lineswitches, the number of secondary… … Sometimes secondary lineswitches are used to reduce trunks betweenmain offices, and they are then generally placed between the first selectorswitches and the repeaters on the outgoing trunks. When the secondaryswitches are inserted between the lineswitches and the first selectors, thecircuit is…
Telephone
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