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).
Potential manufacturing defects in coils and proposing two tests to improve them.
| Identifier | ExFiles\Box 52\3\ Scan336 | |
| Date | 18th October 1919 guessed | |
| Contd. -3- B. There may not be an adequate margin of safety as regards insulation stress, in order to allow for slight imperfections in construction and material; almost bound to occur on production manufacture or C. Slight defects in material and construction may have occurred during manufacture on "production". In this connection the following tests suggest themselves:- 1. Endurance test on a production coil (one which passes production coil test) on an engine running at slow speeds on load on the bench with spark gaps wider than normal. If the coil breaks down dismantle and carefully unwind to see if fault can be located. 2. Construct and test a coil with smaller (i.e. fewer turns) high tension winding, filling up the coil with more insulation in the regions marked "a" and with more effecient internal insulation. HT Core It may be possible to get sufficient No. of turns, if silk covered copper is used on H.T.). Contd. | ||