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).
Performance of a dynamo-battery system and a two-rate charge switching scheme.
| Identifier | ExFiles\Box 163\6\ img085 | |
| Date | 9th December 1930 | |
| X6016 To R.{Sir Henry Royce} from EFC. c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} By.{R.W. Bailey - Chief Engineer} c. PN.{Mr Northey} Hd.{Mr Hayward/Mr Huddy} c. MX.{John H Maddocks - Chief Proving Officer} EP.{G. Eric Platford - Chief Quality Engineer} EFC2/AD9.12.30. X.8780 X.5780 PERFORMANCE OF DYNAMO-BATTERY SYSTEM AND TWO-RATE CHARGE SWITCHING SCHEME. X.6016. When the two-rate charge switching scheme was under consideration in conference with E.{Mr Elliott - Chief Engineer} at Derby, the possibility of what we then called a "one way interconnection" was considered. The two-rate charge switching scheme standardised has complete interconnection in that full dynamo output definitely goes with head lamps "on" and reduced dynamo output with head lamps "off". In many cases it would no doubt be an advantage to have only a one way interconnection, which though permitting full dynamo output with the head lamps off, does not permit reduced dynamo output with the head lamps on. The system with complete interconnection which we have standardised, means that the battery cannot normally be charged at a higher rate than the output of the dynamo as limited by the field resistance. With a high value of this resistance this is in many cases a distinct disadvantage e.g. in a case where a client normally uses his car for daytime work but occasionally makes a bigger demand on the battery during night town work. A fast rate of charge given to a low battery does very little or no harm and the prevention of this merely by the presence of a rather high field resistance will be agreed to be, in the case we have cited, a distinct disadvantage. The two-rate charge scheme really arose out of a demand for more current for head lamp lighting during fast night runs, necessitating a high output machine. The 48 coil modified pole piece machines were developed for this purpose, at the expense, as it has been realised, of somewhat later cutting in. A field resistance was provided to prevent excessive charge of the battery in daylight running or touring. In the first instance one value of this resistance, representing a compromise between the two extremes, was arrived at. From the results experienced by Sg.{Arthur F. Sidgreaves - MD} on 58-GN it is now realised | ||