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).
Improvements to the R.R. Goshawk Condenser, including capacity and material considerations.
| Identifier | ExFiles\Box 52\3\ Scan042 | |
| Date | 9th December 1921 | |
| To EFC. {E. Fowler Clarke - Electrical Engineer} from R. {Sir Henry Royce} c. to CJ. c. to PN. {Mr Northey} c. to Hs. {Lord Ernest Hives - Chair} c. to Wor. {Arthur Wormald - General Works Manager} c. to Wd. {Mr Wood / Mr Whitehead} X4430 RS {Sir Henry Royce's Secretary} /M9.12.21. X.4430 - R.R. Goshawk Condenser. X.2512. In reply to your EFC {E. Fowler Clarke - Electrical Engineer} 2/T6.12.21., this trouble should never have existed but it has forced us into scheming an improved arrangement so that ample capacity will be fairly easily obtained. I have written elsewhere that the capacity should be from .3 to .4 micro-farad, i.e. slightly more than is required for the maximum length of steady sparking so as to be very certain about protecting the contacts. It is certain that the flat folded condenser is the least expensive. Probably aluminium foil would be superior mechanically, and also for electric conductivity; it will not solder, and whether it will make good contact by simple pressure should be tested. You will notice in all cases that we have allowed room for 3 inserts to make contact with the tin foil or aluminium foil; these inserts can be made of copper or any metal found advantageous. American Bosch condenser should fail in use because both earth and the connection to contact arm are very unreliable, and from your own tests quite a good contact is needed. They stuff in a crumpled up piece of foil as packing. Mica was suggested by me as the only suitable | ||