. The telephone system of the British post office. A practical handbook . Junctions to Post OJtce Local Switch. 105 Where there are more than three sections the tags 47 and 48 should betaken to the test board and there joined to the battery by means of Ulinks. If this is not done very great difficulty will be experienced intracing faults, owin|[ to the multiplicity of teed connections. It shouldbe noted that only one battery must be used for the whole exchange. Ifa single set of cells proves inadequate, other single sets joined in parallelmust be added. The disposition of the apparatus is indi
. The telephone system of the British post office. A practical handbook . Junctions to Post OJtce Local Switch. 105 Where there are more than three sections the tags 47 and 48 should betaken to the test board and there joined to the battery by means of Ulinks. If this is not done very great difficulty will be experienced intracing faults, owin|[ to the multiplicity of teed connections. It shouldbe noted that only one battery must be used for the whole exchange. Ifa single set of cells proves inadequate, other single sets joined in parallelmust be added. The disposition of the apparatus is indicated in Figure 91. It will beseen that the space for Post Office subscribers is reduced from 10 to 5, asoperators cannot attend to Post Office renters in addition to trunks ; and,indeed, at all the larger offices a separate switch is provided for transfer circuits have^lready received suitable notice. In the case of C sections, record tables are always provided, and hencewe notice the disappearance of the three service self-restoring indicators. Lon^L St^irc-. ?ir,UFE 92 A strip of five-point switch-springs is provided for junctions to the PostOffice local switch. Where the renters are all accommodated upon slacksections, these junctions are, of course, not required ; the switch-springsare, however, always fitted. Two junctions are provided from each section to the local switch, wherethey terminate in switch-springs with two springs only. These latter arefitted in strips containing twenty switch-springs. No. i switch sectionsjunctions are numbert d i and 2 ; No. 3s, 5 and 6; No. 20s, 39 and 40,and so on. A call wire is provided to the local switch and this passesround all the sections, being connected to each call wire key. The localoperator listens continuously, and receives all instructions upon it. Thus,if Section 3 wants subscriber No. 20, she depresses the Post Office callwire key and says 20 on junction 5, or, if junction 5 is in use, on call wire arrangem
Size: 1911px × 1307px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjecttelepho, bookyear1901
