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).
Replacing an unsuitable Smith's dimmer switch with a more robust Lucas unit.
| Identifier | ExFiles\Box 168a\2\ img432 | |
| Date | 17th May 1939 | |
| 6139 To By.{R.W. Bailey - Chief Engineer} c. to By/TD. Rm{William Robotham - Chief Engineer}/RC.{R. Childs}7/JH.17.5.39. re Lucas Dimmer switch to DB.{Donald Bastow - Suspensions}2354. This unit is intended to replace the Smith's dimmer switch to DB.{Donald Bastow - Suspensions}2353 which has proved unsuitable. (see Rm{William Robotham - Chief Engineer}/RC.{R. Childs}1/MH.{M. Huckerby}5.4.39). In the Lucas dimmer, the element is embedded in porcelain as in the Heater motor arrangement provides a more robust switch, and eliminates any possibility of the hot element shrinking and charring its former, with a consequent poor contact, a trouble experienced with the Smith's unit. The Lucas unit, received 12.5.39, has completed a bench test, and was found to satisfactorily handle throughout its range, the required load of two 6 watt 12 volt lamps connected in parallel. The total resistance cold is 14.6 ohms which is sufficient when completely in the circuit, to just allow the lamps to glow. We will now fit this type of unit to B.V. cars for final examination. Rm{William Robotham - Chief Engineer}/RC.{R. Childs} | ||