National Telegraphic Union · New York : N.T.U. · leaf 300
instant, thus sending acurrent over the line, but producing no action upon therelay, as its magnetic effect upon the cores is neutralized by the influence of the current simultaneously sent fromthe equating battery. The double key, a, b, c, and a, V, c, fig. 1, consists oftwo separate levers,… … The equating battery, E, is connected through onewire of the relay coils, and the front and middle connec-tions, a and 6, of the left side of the key. The front con-tact a of the right side of the key is connected to one poleof the main battery, B, the other pole being to the ground.The back…
Telegraph
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