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).
Comparison of the reliability of an auto charge control switch versus a green lamp scheme.
| Identifier | WestWitteringFiles\S\March1928-May1928\ Scan064 | |
| Date | 30th March 1928 guessed | |
| -6- Contd. A test on the road will be made to prove the much reduced difference between the operation of the switch cold, as compared with a suitable setting for the hot condition. We Query whether the auto charge control switch throws any more responsibility on the makers than the green lamp scheme. The armature operation is identical through the result is different. The possibility of failure is the same. The inherent reliability of either the auto charge control switch or the green lamp scheme switch (both temperature compensated) is considered to be of a higher order than that of the cutout itself, upon which the correct functioning of the electrical system depends. A failure of either unit is equally less serious in its consequences. An original or developed fault of adjustment is also not serious. In the green lamp scheme in the event of a broken connection in the battery or battery circuit, between the ammeter side of the emergency fuse and the chassis frame, the green lamp would burn out probably without being noticed, and certainly before there was time to put the switch off to prevent such burn out. In this way it does not give the same protection as the auto charge control switch which gives audible, or if the lights are on, audible and visible indications, without doing any harm. Further to this, if the Contd. | ||