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 effect of brush position variation on the output of a Smith Type A Dynamo.
| Identifier | WestWitteringFiles\D\May1920\ Scan70 | |
| Date | 18th May 1921 | |
| OUTPUT (AMPERES) 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 580 R.P.M 13.6 VOLTS DYNAMO SPEED (R.P.M.) 0 500 1000 1500 2000 2500 3000 EFFECT OF VARIATION OF BRUSH POSITION ON OUTPUT OF SMITH TYPE A DYNAMO BRUSHES FULLY FORWARD BRUSHES NORMAL BRUSHES FULLY BACK 14.0 14.5 15.0 15.40 15.40 VOLTS E7C 18/5/21 | ||