Electrical engineer's pocket-book: a hand-book of useful data for electricians and electrical engineers (1901)
Foster, Horatio A. (Horatio Alvah), 1858-1913 · New York, D. Van Nostrand co.; London, E.& F.N. Spon, ltd. · leaf 269
in Fig. 47.Fig. 48 is a diagram of a two-circuit, singly re-entrant, double-wound ring. Drum WiiB4li]i£.«>, In order that the E.M.F.s generated in the coils of a drum armature maybe in the same direction, it is necessary that the two sides of each coil be infields of opposite polarity, and… … Figure 49 shows the Von Hefner-Alteneck drum winding, used principallyin small and smooth core armatures.
Electrical engineering
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