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).
Instruction sheet detailing the construction and resistance of a Lucas Headlight Dimmer.
| Identifier | ExFiles\Box 61a\1\ scan0122 | |
| Date | 14th October 1921 | |
| RR 238 (500 Bks.) (SF 152. 6-11-18.) MP 197880 ROLLS-ROYCE LIMITED. INSTRUCTIONS. To: EFE Order No: AD 28 Customer's No: 1 X 4291. X 4291. Lucas Headlight Dimmer. This is made with two coils of resistance wire, arranged with sliding contacts, operated by a plunger on the dash. The resistance is 2.9 ohms cold, and rises to just over 3.0 ohms when warm. This seems to be a very suitable amount for the purpose. The effect of the dimmer on ordinary metal - filament + half-watt lamps is shown in the table attached. Circuit voltage 12.6. Signed This Sheet must be filed on completion of the work. | ||