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).
Questioning the purchase of Dubiliers condensers and suggesting design modifications for in-house production.
| Identifier | ExFiles\Box 52\3\ Scan013 | |
| Date | 21th November 1921 | |
| To Enc. from R. {Sir Henry Royce} Copy to Mr. BY HS. {Lord Ernest Hives - Chair} X4430 R9/G21/11/21. X4430 RE CONDENSERS - EFC {E. Fowler Clarke - Electrical Engineer} 1/T16/11/21. X2572 I do not understand why we are buying Dubiliers conden-sers for our 40/50 H.P. Are they cheaper than what we can make? As we understand these are mica condensers and made to our design we cannot understand how it is that they can be made by Dubiliers for less money than we can make them. Perhaps this can be explained in some way. I think there is some misprint in your memo which says .011 mica. I read this to mean .0011, and assume this to be the average with a plus and minus limit of .005". If this is so one would expect that you could select it so as not to exceed an aver-age of .00125", i.e. the combined thickness of double paper used in the Bosch condenser. Now supposing that the Bosch condenser being made of paper, which material has a factor of two, a mica condenser ought to have considerably more capacity. We agree to any modifi-cations being made that will utilise the space to greater advan-tage, such as the omission of studs, and the whole pile being active material and insulation, perhaps using a central stud right through the mass, and a plain piece of thin sheet bakelite at the top and the bottom. The connections could also be made right at the end, and not pushed over the condenser. By taking full advantage of this perhaps nearly twice the capacity could be arranged, possibly slightly taper shape could be obtained, and by increasing the angular length and forming square radial ends with small rounded corners. RECEIVED NOV 22 1921 R. {Sir Henry Royce} | ||