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).
Dynamo output and voltage performance graph for a 20 HP model.
| Identifier | ExFiles\Box 165\6\ img158 | |
| Date | 11th February 1925 | |
| 20 h.p. Handwritten notes: R.4.K / 11.2.25 Test No 119 CUT IN 7.5 M.P.H. Vertical Axis (upside down text): AMPERE OUTPUT APPROX. OPERATING VOLTAGE Horizontal Axis: DYNAMO R.P.M. CHASSIS M.P.H. WITH 33"x5" DIA TYRES | ||