From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The mathematical principles of armature wave windings.
| Identifier | ExFiles\Box 68\4\ scan0166 | |
| Date | 9th October 1918 | |
| E7.C EFC/L.9.10.18. X.1640. ARMATURE WINDINGS. (1) Wave Windings. Let number of conductors = n (virtual). " " poles = p Then both n and p must be even. In n ± 2 conductors there must be p steps { (+ means progressive) { (- " retrogressive) Hence pitch z = (n ± 2) / p The pitch must be odd. Hence (n ± 2) / P = 2k + 1 where k is an integer representing step of winding. n ± 2 = (2k + 1) p { n = (2k + 1) p ∓ 2 { z = 2k + 1 (Handwritten note pointing to the '∓' symbol: {- means progressive, + means retrogressive}) | ||