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).
Comparative analysis of various dynamos and outlining desired performance characteristics.
| Identifier | ExFiles\Box 60\4\ Scan026 | |
| Date | 11th February 1931 | |
| EFC. FROM E.{Mr Elliott - Chief Engineer} X6099 EL/M11.2.31. C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} C. to FW. EB. SY. X.6100 re. DYNAMO OUTPUT. X 6099. In reply to your memo. EFC1/AD9231., I still think it would be useful to obtain one of the simpler Lucas machines for analysis. The dynamo on the Vauxhall has but two terminals. It is a smaller machine than our 25HP. dynamo but it may weigh more owing to the use of cast iron instead of aluminium for the end covers. We should like to know how the output compares with the improved RR. machine in course of construction on the 14 V.{VIENNA} basis. We consider it is misleading to assess the weight of a machine purely on its peak output. Our recent experience demonstrates the relative importance of other features such as that of early cutting in and maintenance of charge with speed. Also the size of machine is of rather greater importance than its weight owing to the restricted room available under the bonnet. We feel that no effort should be spared to improve our dynamo output until we reach the point where 60 watt lamps can be standardised. We believe these will be required eventually on the 25HP. chassis as well as P. 2. We suggest that in parallel with the other experiments going forward that dynamos for both RR. chassis should be in preparation wound in the same way as the machine mentioned at the beginning of this memo. We consider that even with automatic control it will still be found necessary for the ideal characteristic performance curve plotted on a speed basis to maintain a level output at all times shewing a positive charge of 2 to 4 amps. above maximum load - i.e. for road speeds of 20 MPH. and over. E.{Mr Elliott - Chief Engineer} | ||