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).
Instructions and test results for a 20hp Dynamo M with modified armature coils.
| Identifier | ExFiles\Box 68\4\ scan0270 | |
| Date | 10th July 1928 | |
| RR 238 (150 BKS.) (OB 461-8-12-24) MP 306975 X 5663 ROLLS-ROYCE LTD. INSTRUCTIONS. To C.F.C. Order No. A.D. 9. Customer's No. X 5663. 10. July 1928 20hp Dynamo M with 3-turn Armature Coils This machine is standard except that the armature is wound with three-turn coils of 18 SWG wire instead of four-turn coils of 19 SWG. The main brushes are 7° retarded from neutral. The machine was run on peak output at schedule voltage, and after adjusting the control brush to 126° from the positive, the output was 15.5 amperes at 2150 rpm (volts 18.4). The temperatures were 26° ambient, 59° rise, 85° total. The cut-in speed (14.0 volts) was then 945 rpm and at 3000 rpm the output was about 14.0 amperes. (cont-d) Signed This Sheet must be filed on completion of the work. | ||