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).
Confirming alterations to a 20 HP dynamo armature winding.
| Identifier | ExFiles\Box 57\2\ Scan114 | |
| Date | 24th February 1928 | |
| To BY/RD. from EFC. X5783do EFC6/T24.2.28. This is to confirm that as arranged in conversation you will instruct a standard 20 HP. dynamo armature with the winding altered in the manner suggested, i.e. each coil to be parallelled into two circuits of two turns each instead of as at present one circuit of four turns. This will give only half the number of virtual conductors and the cutting in speed will be put up accordingly, but owing to the fact that the armature resistance will be quartered, the dynamo will be capable of a much bigger output when it does cut in at a later speed, and we think it will be found that the control will be of a similar nature, but the machine will give its peak output (rather bigger than at present) probably at the high speed at which the customer desires it. We hope and think it may be the case that no alteration will be required to the field winding. EFC. | ||