Elementary telegraphy : a manual for students; written specially to meet the requirements of the ordinary grade of the subject as published in the syllabus of the city and guilds of London Institute (1910)
Pendry, H. W. (Henry Walter) · London ; New York : Whittaker & Co. · leaf 205
Ilij. 108.—Uuivcrsal battery : .s.C. inteniieliati; station. … Vu.. 16J.—Uiiiver.sal batleiy : D.C. iijj station. For down station reversebattery {U) aiil D of relay anrl galvanometer terminals. set requires positive, while the down set uses negative,consequently two separate batteries must be provided. An TELEGRAPH SYSTEMS 195 iuterjuediatc station IS.C.…
Telegraph
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