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 44
originate in office No. 11, and one first selector shows how anynumber of first selectors will act. The first selectors choose the districts.If 1 is the first digit of the call number, the first selector will take thefirst digit of the call number, the first selector will take the first level,which… … Fig. 26.—Large exchange divided into districts. is 2, the first selector will secure a trunk to a second selector in anothergroup, whose bank is trunked to third selectors in district 2. The secondpull of the dial lifts the wipers of this second selector to the level corre-sponding to the office in…
Telephone
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