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).
High output dynamos and the two-rate charge scheme.
| Identifier | ExFiles\Box 163\6\ img101 | |
| Date | 18th December 1930 | |
| X6016 Wor.{Arthur Wormald - General Works Manager} from EFC. c. Ev.{Ivan Evernden - coachwork} EFC1/AD18.12.30. X.6005. HIGH OUTPUT DYNAMOS AND THE X.6016. X.6006. TWO-RATE CHARGE SCHEME. Ey5/N16.12.30. We agree with Ev.{Ivan Evernden - coachwork} in general that the new 48 coil high output dynamos working in conjunction with the new switchbox and distribution box adapted to the two-rate charge scheme, comprise the best general equipment that has so far been seriously proposed for standard. We do not, however, agree with the sole use of a 6" resistance but that this 6" resistance is definitely suitable for one extreme group of cases. For the great majority of cases we consider that a 16" resistance would be suitable and in a few cases of the other extreme where the car is little used in Town conditions but mainly in summer touring conditions, we consider the 25" resistance might be found, as on the 10,000 mile test in France, to provide the necessary current requirements. FL/M13.12.30. We agree that the following are simultaneously desirable :- (a) To cut in at 15 miles per hour. (b) To have enough current available to maintain all the running demands at speeds above 25 miles per hour. (c) To have a non-falling output characteristic as the major output on the two-rate charge scheme. The output at present provided by the 48 coil high output machine is nearly the best balanced compromise between these requirements that it is possible in the present limited circumstances to produce. We say "nearly" because we hope to produce some further slight improvement and are continuously working to that end. | ||