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 377
mall auxiliary power-boardat the top of the lineswitch upright. This pair of bus bars is strappedto a similar pair of bus bars on the next line switchboard of the group;the strapping is continued until all the boards in the .group have beenreached. 352 AUTOMATIC TELEPHONY From each pair of bus bars…
Telephone
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