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).
Query comparing the specified characteristics of a generator for an aircraft engine revolution indicator with the Rolls-Royce equivalent.
| Identifier | ExFiles\Box 33\5\ Scan031 | |
| Date | 14th August 1922 | |
| X. 1807. EFC. Rg{Mr Rowledge}9/W14. 8. 22 GENERATOR FOR REVOLUTION INDICATOR. I understand that the Generators used in connection with Revolution Indicators for Aircraft Engines are specified to have the following characteristics:- Voltage at 1,000 RPM in either direction of rotation: 5.02 ± 0.02 volts at 15°C. Voltage at 2,000 RPM. in either direction of rotation: 10.00 ± 0.02 volts at 15°C. Armature Resistance 18.75 ± 0.75 ohms over brushes, and temperature coefficient substantially that of copper. Substitutional Resistance 2,000 ± 10. ohms at 15°C. and temperature coefficient negligible. Will you please let me know how these figures compare with the Rolls-Royce Generator. Rg.{Mr Rowledge} Rg.{Mr Rowledge} Hs{Lord Ernest Hives - Chair} RECEIVED AUG 14 1922 | ||