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).
Issues with a vibrator control system, battery charging, and sulphation.
| Identifier | ExFiles\Box 60\3\ Scan203 | |
| Date | 13th March 1933 | |
| 86092 To FN. from E.{Mr Elliott - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} for. Hx. By.{R.W. Bailey - Chief Engineer} Hx/Wst. E.1/HP.13.3.33. re Vibrator Control. With regard to the point raised by By.{R.W. Bailey - Chief Engineer} at the conference of Thursday, March 9th, I think the trouble experienced can be largely explained by the fact that By's battery was not being charged in conjunction with a vibrator controlled unit at all, but by a voltage measuring device which earthed the magneto and stopped the engine and dynamo as soon as the P.D. was enough to operate the trip controlled switch. Any sulphation of the battery causes the trip to operate earlier by reason of higher voltage, and thus the condition is aggravated. I have a very similar lighting set at West WitteringHenry Royce's home town and in the handbook supplied by the makers they do not recommend running on the automatic charging control if it can be avoided, but plainly state they prefer the charging to be shut off manually when the battery gasses. The controlling unit in my case consists of a coil of thin wire wound round a bimetal strip, and the end of the strip engages a notch on a spring controlled switch. The device is not likely to be very accurate. In the case of vibrator control, as is well known, the charge is not cut off but only diminished gradually as the voltage rises giving a tapering off of the value of the charging current. A vibrator control system would tend to break down a state of sulphation rather than encourage it. We are putting in hand an experiment to show the value of the charging current and voltage for any given state of charge of the battery with vibrator control. In the case of 58-GN Ha/Wst states the dynamo fitted is rated to develop 14 amp at 13 volts and if the maximum current shown at any time on the ammeter does not exceed 7.5 amps then | ||