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 comparison graph of Rotax, Lucas, and Smith dynamos showing Ampere output versus speed.
| Identifier | WestWitteringFiles\E\November1920\ Scan58 | |
| Date | 11th November 1920 | |
| AMPERE OUTPUT DYNAMO SPEED (R.P.M.) LUCAS E.575. (HOT) AVERAGE OF THREE SMITH 2D (HOT) (AVERAGE OF THREE) SPECIFIED PERFORMANCE (HOT) ROTAX COLD ROTAX FULLY HOT ROTAX FIELD CURRENTS COLD HOT 14.6 14.0 14.2 13.6 13.4 13.2 ROTAX AT12 dynamo cold and fully hot output curves with curve of specified hot performance of dynamo for RR car, also average performance curves (hot) of LUCAS E.575. and Smith 2D. dynamos. 340 R.P.M 12.4 VOLTS 440 R.P.M 13.6 VOLTS 540 R.P.M 13.6 VOLTS 710 R.P.M 13.6 VOLTS EA.C 11.11.20 | ||