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 results of main brush position tests on a Goshawk dynamo.
| Identifier | WestWitteringFiles\J\May1923\ Scan32 | |
| Date | 19th October 1933 | |
| I OPERATING VOLTAGE Amps | Volts 0 | 13.8 1 | 13.9 2 | 14.0 4 | 14.1 5 | 14.2 6 | 14.3 7 | 14.4 8 | 14.5 9 | 14.6 10 | 14.7 11 | 14.8 12 | 14.9 12.5 | 15.0 | 15.25 AMPERE OUTPUT DYNAMO R.P.M. MAIN BRUSH POSITION TESTS OF R GOSHAWK DYNAMO Control brush adjusted in each case to give a final temperature of 75°C at maximum load. Final ambient temperature 20°C. CURVE 4 Brushes 4° retarded 78.5°C CURVE 3 Brushes 3° retarded 72°C CURVE 2 Brushes 2° retarded 75°C CURVE 1 Brushes 1° advanced 73.5°C CURVE N Brushes in neutral position 72°C Positions measured circumferentially on carcase from neutral position. Top Right: H.Ch. 19.X.33 E.7- | ||