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 showing the ampere output of a 20 HP dynamo at various RPMs and resistances.
| Identifier | ExFiles\Box 165\6\ img022 | |
| Date | 26th May 1926 | |
| AMPERE OUTPUT OPERATING VOLTAGES 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 14.0 14.8 15.55 16.2 16.8 17.3 17.7 DYNAMO R.P.M. 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 4000 OUTPUT OF 20 HP R DYNAMO AS STANDARD AND WITH VARIOUS RESISTANCES IN THE FIELD CIRCUIT AS LABELLED. ALL CURVES FOR OPERATION WITH RESISTANCES TAKEN AT APPROXIMATELY 65°C. CURVE LABELS: STANDARD 20 HP IGNITION BALLAST 1.725 ω O.M.F. HEAD LAMP 40/50 H.P. IGNITION BALLAST REMY IGNITION BALLAST BOTTOM RIGHT: 20 H.P. HANDWRITTEN NOTE: FH / 26.5.26 E3C | ||