File:Electrical instruments and telephones of the U.S. Signal corps (1911) (14569885478).jpg

Identifier: electricalinstru00unitrich (find matches)
Title: Electrical instruments and telephones of the U.S. Signal corps
Year: 1911 (1910s)
Authors: United States. Army. Signal Corps
Subjects: Military telegraph -- United States Military telephone -- United States
Publisher: Washington, Govt. print. off.
Contributing Library: University of California Libraries
Digitizing Sponsor: MSN

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^, as in practice it would be, is not magnetized. If a battery be placed in the circuit at the distant end of wire 1it will cause the potential, or pressure, to yary so that a difference ofpotentials is brought about at the terminals of the bridge wire and a
Text Appearing After Image:
Fig. 40. current Ayill flow from the terminal of higher to the teiMiiinal oflower pressure. If then (as in the case of the differential method) each end of aduplex circuit be equipped with the bridge arrangement, etc.. it isclear that the yariation of pressure at the terminals of the bridgewire, due to the operation of the distant keys, will effect an analogousresult to that of the excess of current in <me of the coils in the differ-ential arrangement of the coils of the relays, namely, a current willflow in the coil and the core will be magnetized. In the single Morse system, as stated, when any one key is open itopens the entire circuit; consequently, during that time, no other keycan operate the circuit. It is clear that such a result followingo))ening of one of the keys in a duplex telegraph system would befatal to success. This result is avoided in duplex teiegra))liy by theuse of keys, or transmitters, of peculiar construction, which will bedescribed later on. ELECTRICAL INST

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