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).
The performance and voltage drop tests of a Lucas two-way switch for a central lamp scheme.
| Identifier | ExFiles\Box 61b\3\ scan0299 | |
| Date | 20th March 1931 | |
| W/S. X6073 Cx{Major Len W. Cox - Advertising Manager}/Hdy.{William Hardy} from EFC. c. E.{Mr Elliott - Chief Engineer} EFC1/AD20.3.31. X.6072/3. LUCAS AND R.R. DESIGN OF TWO-WAY SWITCH FOR CENTRAL LAMP SCHEME. Answering your CX{Major Len W. Cox - Advertising Manager}/Hdy{William Hardy}2/V17.3.31, a Lucas switch has now run 4,600 miles on experimental chassis 20-EX without trouble. This switch was included in some loss of P.D. tests recently made and reported to Wor.{Arthur Wormald - General Works Manager} in our EFCS/AD6.3.31. The results of these tests in so far as chassis 20-EX with 60 watt head lamps lighted from the battery (generator not running) is concerned, were (a) The loss of P.D. between the battery positive terminal and the main emergency fuse was .3 volt. (b) The loss of P.D. between the main fuse and the head lamp fuse was .4 volt. (c) The loss of P.D. between the head lamp fuse and either head lamp was .7 volt making a total loss of 1.4 volt. Item (c) contains the effect of the Lucas switch the exact amount of which separately, we do not know, but on independent bench test on a Lucas switch in new condition the loss of P.D. at 10 amperes did not quite reach .2 volt and therefore would not appear to be a serious proportion of the total loss including that in the wiring. Messrs. Lucas themselves have maintained that they have done ample testing to prove that this Lucas switch is quite O.K. for the purpose i.e. of carrying 10 amperes in a 12 volt head lamp circuit. We are arranging for a second switch of this type to be put on another experimental car 19-EX which at present is fitted with a Court switch. | ||