. The practical telephone handbook and guide to the telephonic exchange . tem in If an earth return is used instead of a second-line wire, n6 PRACTICAL TELEPHONE HANDBOOK the terminals L 2 are connected to earth as indicated in different type of battery wall instrument is shown in Fig. 123, this beingfitted with a cradleswitch and hand-micro - telephone,also with a 4-point instrumentplug and jack, bymeans of whichthe can bereadily discon-nected. Fig. 124 showsa table set for bat-tery working asmade by MessrsEricsson & connectionsare shown in , in whi
. The practical telephone handbook and guide to the telephonic exchange . tem in If an earth return is used instead of a second-line wire, n6 PRACTICAL TELEPHONE HANDBOOK the terminals L 2 are connected to earth as indicated in different type of battery wall instrument is shown in Fig. 123, this beingfitted with a cradleswitch and hand-micro - telephone,also with a 4-point instrumentplug and jack, bymeans of whichthe can bereadily discon-nected. Fig. 124 showsa table set for bat-tery working asmade by MessrsEricsson & connectionsare shown in , in which theloop line, or line-and - earth ter-minals, are shownon the extremeright. The instru-ment is connectedup on the shuntsystem, the cradlespring short - cir-cuiting the speaking circuit when the cradle is pressed down,and short-circuiting the bell when the is transmitter is worked by the two cells on the earthedend of the battery. The connections of the wall set Fig. 128are similar to Fig 125. Central Energy Instruments.—For the common battery. 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
Size: 1226px × 2037px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjecttelephone, bookyear19
