Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems (1921)
Smith, Arthur Bessey, b. 1875, Campbell, Wilson Lee · New York : McGraw-Hill · leaf 220
eld. Free calls do not affectthe clock and conversation must be held through the electromagnetand its shunt. Coin Collectors for Subscribers Stations.—Figure 180 is a photo-graphic reproduction of two views of a coin collector—one with the coveron and one with the cover removed—of a type that is… … Fig. ISO.—-Interior and exterior views of automatic coin collector. of the collector is a polarized relay P.R. which through its armature armand a trigger controls three contact springs which are so connected upthat when they are closed together they short-circuit the telephonetransmitter and place…
Telephone
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