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).
Introduction of paper insulation between the primary winding layers of an ignition coil to improve reliability.
| Identifier | ExFiles\Box 45\4\ Scan183 | |
| Date | 25th July 1923 | |
| EFC. C. "H" Dept. (Struck through) C. Mr. Gamble. (Struck through) C. Mr. Hayes (Struck through) X4079 BY5-P25.7.23. X.4079 (Struck through) IGNITION COIL. X3445 (Struck through) Re the question of absence of the paper insulation between the different layers of the primary winding which I mentioned to you today, as I find that we are winding the outside of the coil when it is completed, with silk, I am of the opinion that we should at once at least experimentally introduce an insulation paper between each layer of the primary, allowing for same by retesting the amount of silk covering on the outside of the coil. I have instructed "D" Dept, to order up three coils treated in this way. Apparently the new coil will not have any paper insulation between the layers of the primary. It appears to me that since so many of our failures have taken place in the primary winding it is very essential that we should, as soon as possible, introduce a paper insulation on the proposed new coil as well as the old type. If you consider this requires testing out to any marked extent I think such tests should be put in hand without delay. If you see no objection to the introduction of a paper or oil silk insulation between the layers of the primary, I think we should attempt to do it at once, as apparently the introduction of this layer of insulation should materially increase the reliability of the coil. BY.{R.W. Bailey - Chief Engineer} EFC | ||