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).
Possibility and initial testing of an electrical speedometer using an alternator and milliammeter.
| Identifier | WestWitteringFiles\U\May1930-July1930\ Scan038 | |
| Date | 20th May 1930 | |
| To R.{Sir Henry Royce} from AFC. c. Sg.{Arthur F. Sidgreaves - MD} c. E.{Mr Elliott - Chief Engineer} Ry. c. FN. Wor.{Arthur Wormald - General Works Manager} c. RE. Hs.{Lord Ernest Hives - Chair} ORIGINAL EFC2/AD20.5.30. X.6025. ELECTRICAL SPEEDOMETER. Probably Mr.Elliott will by now have mentioned to you the possibility for electrical speedometer purposes described in our EFC5/AD25.4.30 addressed to E.{Mr Elliott - Chief Engineer} of utilising a combination of small alternator with fixed windings, and alternating current milliammeter rendered possible by the combination of a small bridge type metal rectifier unit incorporated in the case of a moving coil D.C. instrument of otherwise orthodox design. As a result of our EFC5/AD25.4.30, we received a note from FN. favouring this idea and offering us for trial a small hand operated alternator removed from a hand operated flash lamp. This has since been received and in fact, the functioning of this alternator in combination with an A.C. milliammeter of the type described has been demonstrated to FN. in this laboratory. Further tests will probably be made using an inductor type magneto (stationary windings) as an alternator to prove the proportionality, in the right electrical circumstances, of instrument deflection to alternator speed. | ||