The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 342
nother half second. 2. Lamp Flashing; to make for 0*6 and break for 0-9 secondso as to complete four interruptions in six seconds. 3. Interrupted Ringing; contact for three and break forthree seconds. Pulsating currents, both positive and negative, are now alsoprovided for party-line ringing. THE… … Fig. 317.—Power Switch-Board motor generator, being arranged to be driven by current fromthe storage battery. The connections of these machines are shown in the left-hand top corner of Fig. 318. Auxiliary Apparatus.—A number of instruments are re-quired in connection with the batteries, generators,…
Telephone
Internet Archive · Northeastern University Library · Public Domain Mark 1.0. Free to use for anything.
