The telephone system of the British post office. A practical handbook (1901)
Herbert, Thomas Ernest · London, New York, Whittaker and Co. · leaf 63
erator in series, since we should have to waste a goodly proportion ofthe energy of our distant generator in overcoming its resistance. A switchis therefore placed on the armature of the generator, by means of whichthe generator is short-circuited when not in use, but immediately thehandle is… … Figure 38. which the wheel driving the armature is fixed, that when rotated it movesover slightly to the right, thus breaking a contact. The spindle has a pinput through it, and this pin rests in two triangular grooves. It is held tothe narrow end by means of a spiral steel spring. When the handle…
Telephone · Postal service
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