Specifications for the multiplex printing telegraph system : theory and operation (1920)
Western Union Telegraph Company · [New York?] : The Company · leaf 269
Fig. 2 LLLLU III III … 8. When the auto control is in its normal position as shown, the circuit from the positive battery on the solid local ring on the distributor runs through the local brush,the local operating segment, binding post DT on the auto control, to both end terminalson the differential relay in the auto…
Telegraph
Internet Archive · Northeastern University Library · Public Domain Mark 1.0. Free to use for anything.
