. The practical telephone handbook and guide to the telephonic exchange . Fig. 54.—Scale \ 6S PRACTICAL TELEPHONE HANDBOOK. Fig. 55.—Scale & vibration. Consequently, the amplitude of the vibrationswhich reach the ear is appreciablylessened. These disadvantages have ledto its gradual displacement by otherforms of receivers. UArsonval Receiver.—In most formsof the double-pole receiver each pole ofthe magnet is fitted with a coil. In theDArsonval both poles are utilised, butonly one coil is used. As shown in Fig. 55,one pole is furnished with a round coil,b, and the other is attached to a soft-ir
. The practical telephone handbook and guide to the telephonic exchange . Fig. 54.—Scale \ 6S PRACTICAL TELEPHONE HANDBOOK. Fig. 55.—Scale & vibration. Consequently, the amplitude of the vibrationswhich reach the ear is appreciablylessened. These disadvantages have ledto its gradual displacement by otherforms of receivers. UArsonval Receiver.—In most formsof the double-pole receiver each pole ofthe magnet is fitted with a coil. In theDArsonval both poles are utilised, butonly one coil is used. As shown in Fig. 55,one pole is furnished with a round coil,b, and the other is attached to a soft-iron cylinder, t, which fits over it, thusforming a box electro-magnet, which concentrates the linesof force due to the operating currents and the magnet inthe centre of the diaphragm. The Collier Receiver.—This is alsoa double-pole receiver in which onlyone coil is used. This coil, withits core, is altogether detached fromthe magnet, the latter being used j\jto polarise the core. The construc-tion is shown in section in Fig. coil is fixed in a central blockof ebonite, and side cheeks ofebonite screwed
Size: 1415px × 1766px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjecttelephone, bookyear19
