. The practical telephone handbook and guide to the telephonic exchange . Fig. 472Front View- Automatic Selector. calling line should now be connected to No. 5679 line; but thisline may be engaged, in which case a busy buzz will be heardon the line. If the line is not engaged the caller presses aringing button, seen under the dial, which again earths the vertical line, energises a ringing relay at the exchange,which sends an alternating current to the ringer of the calledline. Clearing.—When finished speaking, the receivers are hung 5T2 PRACTICAL TELEPHONE HANDBOOK on the prong lever, which, i
. The practical telephone handbook and guide to the telephonic exchange . Fig. 472Front View- Automatic Selector. calling line should now be connected to No. 5679 line; but thisline may be engaged, in which case a busy buzz will be heardon the line. If the line is not engaged the caller presses aringing button, seen under the dial, which again earths the vertical line, energises a ringing relay at the exchange,which sends an alternating current to the ringer of the calledline. Clearing.—When finished speaking, the receivers are hung 5T2 PRACTICAL TELEPHONE HANDBOOK on the prong lever, which, in falling to its lower position, causesa simultaneous earth contact on both wires of the loop. Thishas the effect of restoring all the mechanism involved in theconnection at the exchange, to its normal condition. Connecting Switches.—In addition to his station telephone set,each subscriber has a separate switch mechanism providedat the exchange, by means of which the connections requiredby him are completed. A front view of such a switch isshown in Fig. 472, and a side view in Fig. 473. Each is about13J
Size: 976px × 2560px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjecttelephone, bookyear19
