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 with an improved Goshawk ignition coil, detailing its construction and materials.
| Identifier | WestWitteringFiles\J\January1923\ Scan37 | |
| Date | 23th January 1923 | |
| To R.{Sir Henry Royce} from EFU. c. to CJ. c. to Ry. c. to EP.{G. Eric Platford - Chief Quality Engineer} ORIGINAL EFC1/T23.1.23. X.4079 - RE GOSHAWK IGNITION COIL. On 4-G.II which is to be brought to you tomorrow. we are putting one of the standard coils with longer core, and one which has had done upon it a good deal of experiment in position on the engine and under the worst conditions. This coil, inspite of its bakelite casing has shown itself to be so nearly equal to the stabalite cased coil that, used in the wheelcase position, there would be no doubt of its insulation being so little affected by temperature conditions as not to upset the working of the coil. We are, however, awaiting complete results of experiments with coils with longer and larger cores before proposing the standardisation of such a coil as the present. All the moulded parts of this coil are made of mouldensite which has been proved to be both stronger mechanically and a better insulator under bad temperature conditions than either Elo or American bakelite. Both the coil case and the core are .500" longer than the original Goshawk coil and the primary winding is of 300 turns of .032" S.S.C. wire, in four layers in place of 6, and .002" insulation between each layers of primary winding. Owing to the reduced depth of primary winding and the fact that the secondary winding is also of reduced depth owing to being more spread out and consisting of 45 layers instead of 60, there is an air space Contd. | ||