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).
Continued discussion on dynamo systems and battery charging characteristics.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan041 | |
| Date | 8th October 1926 | |
| Contd. -2- EFCL/T8.10.26. extent we desire by the use of a suitable proportion of series coil. An objection to carrying it too far is that the system becomes less suitable for operation with the battery disconnected. Once, however, it is decided that the system is not to work without the battery, then any desired approximately straight volt-ampere output characteristic can be achived, and the voltage for no ampere output can be arranged to be so high that there is no question but that the battery would be brought up to its full state of charge. We have experiments in progress on the effect of charging a battery to the law V + .25 A = 17, where V is the operating voltage and A the ampere output. It may prove to be necessary that the output characteristic should be more like V + 1/3 A = 18, giving a higher open circuit voltage, 18 in place of 17, but the same amperes, viz. 12, at 14 volts. In the present state of affairs it would appear that we are mostly agreed that what is required is an effective compromise between the two extremes of on the one hand an inherently regulated dynamo with hand control of the charging switch, and on the other hand, a completely externally regulated shunt wound dynamo which in principle would automatically supply current precisely in accordance with the demand. The most promising compromise would appear to be the second one described under the side title "Compromises between the two extreme types of dynamo system" in our note | ||