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).
Auto lighting plants, specifically a permanent magnet instrument and an alternative scheme.
| Identifier | ExFiles\Box 59\1\ Scan275 | |
| Date | 21th February 1928 guessed | |
| -2- Contd. On the auto lighting plaints (Austin and others) a permanent magnet type of instrument is used to make contact at an exact voltage, practically independent of the temperature. This moving coil contact maker has a resistance in series with it made of one of the alloys which has a small negative temperature coefficient. We much thank Mr. Clark for his care, skill and perseverance with this apparatus, but I fear it is not quite in the right direction, and I cannot help asking him to turn his attention to the alternative scheme mentioned in this memo. R.{Sir Henry Royce} | ||