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).
Requesting a quote for a suitable resistance to convert a milliampere instrument into an AC voltmeter.
| Identifier | ExFiles\Box 165\3\ img078 | |
| Date | 3rd July 1933 | |
| X1330 Roy{Sir Henry Royce}/MS. From Hs{Lord Ernest Hives - Chair}/Wst. Hs{Lord Ernest Hives - Chair}/Wst.3/MA.3.7.33. VOLTMETER RESISTANCES. Further to our Hs{Lord Ernest Hives - Chair}/Wst.8/MA.28.6.33., we have noted Messrs.Ferrantis reply to your letter and it would appear a better proposition if we asked them to quote us for a suitable resistance for the instrument we have in mind, which is a Ferranti 2½" rectifier pattern instrument having a scale calibration of 0 to 25 milliamperes. Type No.253P No.35131. Will you please ask them to quote us for a suitable resistance in order to convert this instrument into an A.C. Voltmeter having a range of 0 to 250 volts. Hs{Lord Ernest Hives - Chair}/Wst. | ||