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 type of thermionic rectifying valve used for ball gap voltage measurement from ignition coils and magnetos.
| Identifier | ExFiles\Box 60\2\ Scan066 | |
| Date | 9th January 1931 | |
| X.6094. EFCl/AD. 9th January, 1931. Mr. E.A. Watson, The M.L. Magneto Synd. Ltd. Victoria Works, Coventry. Dear Sir, We greatly appreciated the receipt of your letter ref. EAW/EE. of the 6th inst. in answer to our EFC {E. Fowler Clarke - Electrical Engineer} 2/AD. of the 30th December. We should be very much obliged if you would be good enough to answer a further query for us and that is as to the type of thermionic rectifying valve you employ for the rectification, for ball gap voltage measurement, of the high potentials available from ignition coils and magnetos. We have sent out a number of enquiries to various firms but have so far not been able to come across a valve for this order of voltage which was not also made for a much bigger current capacity than that with which we need to deal in the case of ignition coils. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||