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 20 HP dynamo, showing various output curves against R.P.M. and chassis speed.
| Identifier | ExFiles\Box 62\3\ scan0013 | |
| Date | 3rd January 1930 guessed | |
| 20 H.P. AMPERE OUTPUT APPROX. OPERATING VOLTAGE DYNAMO R.P.M. CHASSIS M.P.H. 11/50 AXLE. 31.4 DIA. TYRES. OUTPUT OF STANDARD DYNAMO AT FULL CONTROL BRUSH RETARD. D.8.A. 8° 119° 80°C. ESTIMATED PERMISSIBLE OUTPUT OF DYNAMO, SUBJECT TO MANUALLY CONTROLLED CHARGE REDUCER, INTER CONNECTED WITH HEADLAMP SWITCH. 8° 120° 80°C. REPRESENTATIVE OUTPUT CURVE OF STANDARD 20 H.P. DYNAMO AT 80°C. SPECIFIED CURVE OF OUTPUT REQUIREMENTS --- FOR -- 20 H.P. DYNAMO --- OUTPUT OF STANDARD DYNAMO AT FULL CONTROL BRUSH RETARD. D.8.A. 8° 134° 80°C. | ||