The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 140
Fig. 120 SUB-STATION INSTRUMENT CONNECTIONS 117 or central energy system of working, which has now becomethe standard method for exchanges, the sub-station instru-ments are of a somewhat simpler character, as the generator … Fig. 121 Fig. 122 and the transmitter battery are both dispensed with, andsometimes also the induction coil. This reduction is, however,partly counterbalanced by the addition of a condenser.
Telephone
Internet Archive · Northeastern University Library · Public Domain Mark 1.0. Free to use for anything.
