The telephone system of the British post office. A practical handbook (1901)
Herbert, Thomas Ernest · London, New York, Whittaker and Co. · leaf 62
direction to that produced when threading in. On moving for-ward to the second position, lines have again been threaded through, butin the opposite direction, as the faces of the armature have been reversed ;this produces an E.M.F. in the same direction as the decaying Unes. Atthis point the E.M.F.… … Figure 37. one revolution of the armature fresh currents in opposite directions areinduced. A very small movement of the armature from the first position causesa much larger alteration in the number of lines passing through the arma-ture than an equal movement from the second position. A…
Telephone · Postal service
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