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).
Failure of an ignition coil and suggesting the use of an insulating varnish instead of asbestos.
| Identifier | ExFiles\Box 46\3\ Scan181 | |
| Date | 13th March 1920 | |
| X.3445 To Mr. Bailey. c. to Sft.{Mr Swift} c. to Ck.{Mr Clark} c. to E.P. EJB2/MP13.3.20. 13th March, 1920. X.3445. Ignition Coil X.3716 I have received a copy of memo. from E.P. to you re the failure of coil on 3-P.P. Chassis. I think I made it quite clear in my report on this coil that I thought the failure was due to the Ballast Resistance being earthed, and that the reason of this being earthed was that it had been tampered with. I note Mr. Wyer suggests that the Resistance Case should be lined with asbestos, so as to prevent broken ends and short circuiting of the case. I would like to point out that we have some very good insulating varnish, viz: Ohmaline. We use this for insulating the Main Switch Cover. Personally, I think if we insulate the inside Ballast Casing with this varnish, it will get us out of our present trouble, as far as earthing of the Resistance is concerned. I should be glad to hear from you as to what you think of my suggestion. At present there is very little room in the Case for an asbestos insulation. E.J.B. E J Brock | ||