File:American telephone practice (1905) (14569859547).jpg

Identifier: americantelepho00mill (find matches)
Title: American telephone practice
Year: 1905 (1900s)
Authors: Miller, Kempster B. (from old catalog)
Subjects:
Publisher:
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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Text Appearing Before Image:
the normal contact, 7, of which is con-nected with one winding, 8, of the relay R, and thence to the signallamp, S, of the line, located in the B division of the switch-board.The other terminal of the lamp is connected through the winding ofthe pilot relay P, to the battery B2. The relay R is provided with asecond movable contact, 9, the normal contact, 10, of which isgrounded, and the forward contact, 11, of which is connected toone terminal of the coil, 8, on this relay. This movable contact isjoined to a similar movable contact, 12, of the relay, T. the normalcontact, 13, of which is likewise grounded, and the forward contact.14, of which is similarly connected to one terminal of the coil, 5. onthe relay, T. The front contact, 15, of the spring, 3, of relay R, ofline wire, 1, is connected to the tip springs of the answering jacks,/ and /, in the A and B divisions, respectively, and the multiplejacks, J2, in the B division, while the front contact, 16, of the pr- lime. \y—«s ^y.
Text Appearing After Image:
0) (*3 c >3i rooc# firi 5 lie o^R FIG. 301.—TWO-DIVISION COMMON-BATTERY SYSTEM.390 THE DIVIDED MULTIPLE SYSTEM. 391 spring, 6, of the relay, T, is similarly connected with the sleeve con-tacts of all the same jacks. The multiple jacks, J2, for this line arelocated upon the B division of the switch-board, this, therefore, be-ing a B line. The similar contacts of all the jacks belonging to anyline are connected in multiple. The sleeve conductor leading to thejacks is also connected with one terminal of the winding, 17, of therelay, T, which winding is connected with a similar winding, 18, ofrelay, R, the other terminal of which latter winding is grounded.The second windings of these relays are, • therefore, connected inseries between the sleeve contacts, all of the jacks, and ground. The pilot relay, P, located in the A division of the switch-board.,controls, through its normally open contacts, the circuit of the pilolamp S2, this lamp being common to all lines of one position; s

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