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).
Examination of two sample dimming switches and a recommendation for an alternative 'Rex Head Lamp Controller' type.
| Identifier | ExFiles\Box 61a\1\ scan0111 | |
| Date | 7th August 1921 | |
| R.R. 235A (100 T) (S.H. 708, 10-12-20) G 2947 X. 4291. To BY from DA{Bernard Day - Chassis Design}/THR. c. to EFC. DA{Bernard Day - Chassis Design}/THR1/CB7-8-21. X.4291. Re Dimming Switch for 49.N.E. - Captain Orred. With reference to ASY{Len Astley - Orders}3/DP2-6-21 on above, and two sample switches handed to us for examination. We examined these and found them fairly well made, one being a "series-parallel" switch , and the other a "resistance" switch. We favour the "resistance" pattern as the range of dimming can be better controlled, but suspected on examination, the resistance in sample being too small, so handed same to EFC for testing purposes. The result of this test confirms our suspicion, (the resistance being .33 ohms, where it should be about 3.4 ohms), otherwise this switch should be a reasonable proposition. At the same time we suggest that you put forward a switch of the "Rex Head Lamp Controller" type, which is very much nicer in use, this pattern having the advantage of never putting out the light at anytime, but merely lowering or turning down same; a very considerable benefit from a driving point of view, eliminating any "blind" periods. Sample switches returned herewith. DA{Bernard Day - Chassis Design}/THR. | ||