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).
Bench testing of a sample Lucas head light dimmer switch.
| Identifier | ExFiles\Box 61a\1\ scan0124 | |
| Date | 14th October 1921 | |
| X.4291. W/Z. EFC4/T14.10.21. To C. from EFC. X+4291 - LUCAS HEAD LIGHT DIMMER . We thank you for the sample Lucas head light dimmer. We have tested this and so far as we can judge on the bench we think that the range of resistance is about suitable either for lamps of the O.M.F. type of 12 volts, 24 watts, or for lamps of the half watt type of 14 volts, 24 watts, such as those we have recently recommended to you. In either case it reduces the current of the two head lamps in parallel to a little less than if the lamps were put in series for reduction. This we think is about correct. We are also of the opinion that the design of the switch is thoroughly good. We shall, therefore, be most interested to hear from you as to the exact way in which you find that the switch is not satisfactory. We can only assume that it must be in the amount of resistance, so that if you have made a test on this on actual head lamps, we should like you to tell us the rating of the lamps which you employed. EFC. | ||