American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 222
ed by the arrow. When the key, k, is opened, the extension of l is caused to descend. As itdoes so the strip /follows p until it is stopped by the contact point p. p then severs con-nection with / and, descending still further, makes contact with /, which it pushes awayfrom p, the whole assuming… … In Fig. 752 a relay, pr, corresponding to R in Figs. 149 and 150, is shown as ata distant end of the line. Its armature controls a sounder s. It is plain that asoften as the battery is reversed by the pole-changer the direction of the currentin the coil of r will also be reversed and, consequently,…
Telegraph
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