The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 113
Fig. 79 Scale J … through lines of very high resistance, which would requirestrong batteries if worked by battery power. Magneto switch-bells consist of four principal parts : 1. The magneto-generator, with its driving gear, by meansof which the signalling currents are produced. 2. The automatic cut-out, an…
Telephone
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