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).
Performance graph of a dynamo for the 20 HP model, showing output against RPM at various temperatures.
| Identifier | ExFiles\Box 165\6\ img033 | |
| Date | 28th April 1937 | |
| 20 h.p. AMPERE OUTPUT APPROX. OPERATING VOLTAGE OUTPUT OF 20 H.P. R.R. DYNAMO 685 (OLD) STANDARD SHAPED SOLID POLES 12 Ampere Fuse with Set Cold 10.0 " " " Hot Temp. 54° - 75° C. Temp. 80° - 93° - 68° C. Dynamo R.P.M. Chassis M.P.H. 11/50 Axle 31/4" DIA Tyres. ADG/37 28.4.37 | ||