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).
Graph of dynamo output in amps versus speed in MPH under different electrical load conditions.
| Identifier | ExFiles\Box 62\3\ scan0208 | |
| Date | 23th February 1931 | |
| 18 GIV DYNAMO OUTPUT HIGH OUTPUT For HALF CHARGE STANDARD DYNAMO WITH TRAILED POLES 23/2/31 AMPS -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 M.P.H. 0, 10, 20, 30, 40, 50, 60 7 discharge HALF CHARGE SIDE & TAIL S/DE & TAIL HEAD SIDE & TAIL HEAD SIDE TAIL FACIA LIGHTS WIND SCREEN WIPER 25-12-30 | ||