The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 297
will be noticed thattwo of the magneto-instrument bells are connected to the a wire of the loop and to earth. The other two bells are connectedto the b wire, and to condensers (of about 2 microfaradscapacity), the other terminals of the condensers being earthed.These condensers are used in order to… … Fig. 276 raising the resistance of the bell branches to a very highfigure, such as 20,000 ohms, or more, so that the currentpassing through the line relay is insufficient to actuate it. The stations having their bells connected to the awire are designated by having X and 1, 2, 3, 4, or 5 addedto…
Telephone
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