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).
Challenges of car battery charging, comparing the Lucas system with a vibrator control system used by Fiat.
| Identifier | WestWitteringFiles\T\March1929-December1929\ Scan311 | |
| Date | 21th December 1929 | |
| EFC. FROM E.{Mr Elliott - Chief Engineer} Copy to SG{Arthur F. Sidgreaves - MD} Copy to PN.{Mr Northey} [Struck through] Copy to HS.{Lord Ernest Hives - Chair} ORIGINAL BATTERY CHARGING. Our local experience of car batteries is that during the summer months they are generally "boiled" away, and in the winter they are in a state of chronic discharge. This applies to the owner driver type of car in general use in the district, and not to the chauffeur driven car, which latter no doubt receives better treatment, but it goes to shew that the seasonal difference in requirements is so great that no one dynamo output curve can satisfy one end of the scale without being in trouble at the other end. In the Lucas system having a "full charge" and "half charge" switch, it is a point worthy of remark that the full charge output from the dynamo is no more than the normal output in general use, and Messrs Lucas' chief anxiety as expressed in the handbook seems to be that the batteries shall not be overcharged. As arranged the Lucas system does not help the man who runs his car mostly in the dark, although it could be so adapted. We merely point out Messrs Lucas' practice in this matter as emphasising further how wide is the range of charging called for. While bearing in mind R's disapproval of any avoidable complication of the electrical installation, it is interesting to recall the system used by Fiats some years ago on their famous 10-15HP. model. This consisted of a vibrator control used in conjunction with a third brush dynamo, and it is inferred that the use of the third brush on the dynamo relieved the vibrator control of the heavy duty of restricting the natural dynamo output, but left it free to vary the charge within certain limits to suit battery requirements. This system also possessed additional advantages insofar that if the main fuse blew or the battery became otherwise detached while the car was being driven, the vibrator automatically took control of the lighting. Furthermore the car could be driven with the lights on for an indefinite period in an emergency without a battery. [Handwritten text in top right corner] X294 X8780 X1589 [Signature] E.{Mr Elliott - Chief Engineer} | ||