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).
Voltage output particulars of the magneto speedometer, also known as a revolution counter.
| Identifier | ExFiles\Box 34\2\ Scan048 | |
| Date | 16th August 1922 | |
| To Rg.{Mr Rowledge} from EFC. X 2238. EFC3/T16.8.22. X.2238 - R.R. MAGNETO SPEEDOMETER. Answering your Rg{Mr Rowledge}9/W14.8.22 I regret I am unable to give you the exact particulars of the R.R. revolution counter, never having made any tests of these instruments myself, but I find from records of tests made by Mr. Hives that the voltage per 1000 R.P.M. is about 2.5, which is only half that mentioned on your note. I do not think we went into the actual quantities quite so precisely, the final setting of the reading of the instrument being provided for by means of varying the series resistances between the generator and the instrument. EFC. | ||