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 298
L-9 and L-10 lighted, the B operator will pull down theconnection, which will allow the cut-off relay .R-48 and the trunk relayjK-45 to fall back. If desired, the number of the called subscriber in the manual office canbe transmitted by impulses and set up before the B operator, who thenneeds only… … SECTION x-xFig. 239.—Side view of 2-motion switch. one key set, having three digits (rows of keys) and an additional row offive keys for party lines. A rotary switch, such as used for the distributor switches and the fre-quency selector, is shown in Fig. 235 and 236. The magnet has a knife-edge…
Telephone
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