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).
Analysis of electrical current consumption in an ignition system, comparing observed and calculated values.
| Identifier | WestWitteringFiles\L\2April1924-June1924\ Scan144 | |
| Date | 29th April 1924 | |
| EFC3/T29.4.24. -3- Contd. The manner in which this consumption varies at different distributor and road speeds is shown on the accompanying curves, there being a curve for the observed current and also a curve for the calculated current, these curves being coincident in the neighbourhood of the normal speed. At lower speeds than normal, the calculated consumption, which is based on an unaltered effective value of the ballast resistance, is more than the observed, and is also more than the observed at the high speeds, in this case the effect being due to the imperfect mechanical action. A curve of observed consumption with a 12 volt supply is also given, and also a curve of the calculated primary current at the instant of break on the same scale. The calculated R.M.S. value of the normal running current is 1.34, as against an average value of .87. At normal speed and 8 volts the current at break is 2.68 amperes and the efficiency of magnetic field production .35. Now referring to your R2/M3424., the 1-1/4 amps. at 6 volts, stated as the consumption of the American battery ignitions is rather ambiguous. There are three reasons why our consumption appears bigger than this, viz., Contd. | ||