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).
The two methods for operating the red lamp ignition warning light.
| Identifier | ExFiles\Box 61b\4\ scan0192 | |
| Date | 15th April 1932 | |
| Hs{Lord Ernest Hives - Chair}/Wst. C - E.{Mr Elliott - Chief Engineer} X6114. BY/RD5/W.15-4-32 Re :- Red Lamp Ignition Warning Light. With reference to Hs{Lord Ernest Hives - Chair}/Wst.8/MA.23-3-32, suggesting the warning light might be lit via the dynamo windings, we agree that it could be operated in this way but it needs a special high voltage bulb. This is a disadvantage when the battery voltage is low, which is just the time we want to be sure that the bulb lights. Further, the filament is always "live", whereas, if operated by a separate pair of contacts, an ordinary standard bulb can be used and this becomes completely "dead" when the cutout operates. Either method can be used, it is just a matter of personal preference. BY/RD. | ||