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).
Investigation into a green lamp switch that has a mysteriously reduced operating voltage.
| Identifier | WestWitteringFiles\T\November1928\ Scan111 | |
| Date | 29th December 1928 | |
| To R.{Sir Henry Royce} from EFC. c. BJ. Wor.{Arthur Wormald - General Works Manager} c. E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. By.{R.W. Bailey - Chief Engineer} EFCl/T29.12.28 GREEN LAMP SWITCH. X.4040. Referring to the third para. of Hs{Lord Ernest Hives - Chair}3/LG27.12.28, of the "two occasions" referred to, only one of these appears to be of any account. One case probably occurred in the very early stages before we had the temperature compensation. We have no record of that case. The case which is of amoment is that of one of our green lamp switches made up from cutout parts and fitted to chassis 12-G4. We have investigated the matter and it transpires that the operating voltage of this switch has mysteriously become reduced. It was originally set to operate at 17.5 volts on the bench when hot, which would mean approximately 17.0 volts on the car when running. When the battery was recently reported to have run down we made another test in position on the car and found that the switch now operated at 15.7 volts warm. We have not previously experienced a change of this nature or magnitude in other temperature compensated green lamp switches, the results of which from the point of view of keeping the battery charged have been, so far as our observation has gone, quite O.K. This matter is being investigated. EFC. | ||