Spon, Ernest, Haldane, Robert, Lock, Charles G. Warnford (Charles George Warnford), 1853-1909 · London ; New York : E. & F.N. Spon · leaf 120
necting Bells and Telephones by one Wire. — Use a relay, as shown in this enables you to adjust the arma- ture to a very great nicety. Linos Fig. 46 at a. The switch 6 has 3 knobs, show the connection of wires from binding-screws to electro-magnet. Of course, these wires go underneath the board.… … have the bell single stroke (the connec- consists of an electro-magnet a, with a tions make thedirterence), and the relay' vibrating armature b ; c is a brass
Workshop recipes · Technology · Industrial arts
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
