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).
Test results on machine performance, comparing amperage, RPM, and sparking at different positions.
| Identifier | ExFiles\Box 68\4\ scan0300 | |
| Date | 8th December 1924 | |
| RR 238 (150 BKS.) (OB 461-8-12-24) MP 306975 ROLLS-ROYCE LTD. INSTRUCTIONS. To __________ 19__ Order No. __________ Customer's No. __________ and the latter 15.7 amperes peak The 17° position gave a cutting-in speed of 955 rpm and peak output of 15.7 amperes. All three curves fell to between 12 and 13 amperes at 4000 rpm. The curves obtained are very similar to that obtained with the 5C coil high output machine having three turns per coil on the armature which embodies a standard carcase. The best of the three appears to be that with the 14° position which involves no alteration to the commutator position. The commutation in the more retarded positions was good whilst in the 11° position there was a greater tendency to sparking. No appreciable magnetic hum was noticeable in any of the positions tested. Signed H/A This Sheet must be filed on completion of the work. | ||