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 345
e last is omitted ifthe exchange is isolated or if it has less than 100 lines and the connectorsdo the trunking. This is the case in the illustration. All but the trunkboard have been fairly well standardized. Because of the many variableconditions found in different places, the trunk board with… … Fig. 272.—Community automatic exchange 100-line (front). switch for starting the charging machine. Above it is the ringing ma-chine which runs by battery current, next the counter-cell switch, andabove it the self-closing reverse-current circuit breaker. At the rightof the power board are the…
Telephone
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