Miller, Kempster Blanchard, 1870-1933 · New York : McGraw publishing company · leaf 430
reduce to some extent the noise which might be thrown onany connected lines by the operation of the buzzer. In Fig. 309 is shown the cord circuit adapted to use with the linecircuit shown in Fig. 308. In the left-hand portion of this figureis shown a key, K, which, when in its normal position,… … FIG. 309.—PRIVATE-BRANCH EXCHANGE CORD CIRCUIT OF CHICAGOTELEPHONE COMPANY. thrown the battery is entirely cut off from the cord circuit. Atthe right of the figure in connection with the calling plug is placedan ordinary combined ringing and listening key, which needs noexplanation. This cord…
Telephone
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