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 output speed performance curves for a 20/25 Dynamo under various conditions.
| Identifier | ExFiles\Box 163\6\ img093 | |
| Date | 4th December 1930 | |
| 20/25 OUTPUT SPEED PERFORMANCE CURVES OF 48 COIL. 20/25 DYNAMO AT 80°C. (12° 123-5°) BRUSH SETTING TEMPERATURE RISE 65°C I. AT SCHEDULE TERMINAL VOLTAGES. II AT A CONSTANT TERMINAL VOLTAGE OF 14.0 III As I. BUT WITH A FIELD RESISTANCE OF 25" OF 26 S.W.G. EUREKA WIRE. (1.8 OHMS.) I II III DYNAMO R.P.M. 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 4000 11/50 AXLE. 31.4" DIA. TYRES. 25 30 35 40 45 50 55 55 F.J.A. 4-12-30 | ||