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).
Experiments on ignition coils to reduce energy output, considering alternative windings and a patent by the Lucas Company.
| Identifier | ExFiles\Box 54\4\ Scan060 | |
| Date | 20th May 1925 | |
| 14654 To R. {Sir Henry Royce} from EFC. {E. Fowler Clarke - Electrical Engineer} c. c. GJ. EY. EFC {E. Fowler Clarke - Electrical Engineer} 2/T20.5.25. RE IGNITION COILS. X.4079 X.4353/4 X.8710. Reference your R1/M11.5.25, now that our ignition coils are consistently satisfactory from the point of view of material of case and consistent output performance, it may be possible to reduce the energy output. With this end in view, we intend making experiments with (1) Additional ballast resistance. (2) Coils with finer primary windings than at present. We have asked for coils to be instructed experimentally with 24 SWG and 25 SWG. in place of the present standard 22 SWG. As regards coils with nearly closed iron circuits, it is difficult to see any reason in principle why these should be an advantage. The only obvious advantage of a coil with an iron core at all appears to be on the score of size of the coil. We have, however, an expression of opinion from Dr. E.O. Turner of the Lucas Company, who apparently patented a coil of this type in 1922. We are endeavouring to obtain copy of this patent specification. He says that he does not think he would say the same to-day as he said in that specification, but that he does think there must be an advantage in the nearly Contd. | ||