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).
Specifications for armature and field winding.
| Identifier | ExFiles\Box 39\2\ Scan029 | |
| Date | 4th December 1920 | |
| Contd. -2- EFC1/T4.12.20. No. of conductors. 432. No. of sections 27 8 turns per section, arranged in the slots as ordinary four-pole wave winding with a step of 1 to 7. The armature to be wound with No.20 S.W.G. D.S.C. wire. The air gap is preferably not to exceed .015" if this can be arranged. We estimate that for the field winding there is only one size of wire which is right, this being No.19 S.W.G. D.C.C. and it is desired to get as many turns as possible of this wire in the space available. The number of turns we estimate will be in the neighbourhood of 195. The coils for the four poles are to be joined in series constituting with the armature a simple shunt winding arrangement; the control will be by means of a vibrator regulator operated principally by main voltage, but to some extent by main current. The pole flux upon which we have worked is 135,000 lines, giving a flux density in the air gap of approximately 9,000 lines per sq. cm. The armature slots are to be milled skewed to the extent of one tooth pitch. EFC. | ||