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).
Letter detailing the test results of Tungsten magneto contact breakers on an aero engine.
| Identifier | ExFiles\Box 35\5\ scan 008 | |
| Date | 1st May 1917 | |
| R.R. 235 A (400 T) (S.C. 536 15-2-16) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1546. X.2894 1st. May, 1917. EFC2/T1517. Messrs. The L.P.S. Electrical Co., 14 Howick Place, Westminster, London. S.W. Dear Sirs, Re Tungsten Contacts With reference to our correspondence re Tungsten Contacts and the two Watford magneto contact breakers, to which you fitted these contacts for us to test, we have now run these two contact breakers on magnetos on one of our Aero Engines with the following results :- For the first few hours running they were quite satisfactory, after that the points of one of the contact breakers chipped off in little pieces, and misfiring ensued. The magneto fitted with a second contact breaker also started to misfire; this was cured by replacing the contact breaker by one with platinum points. There did not appear to be anything wrong with this contact breaker, except that a whitish powder had formed on, and round the Tungsten points. We shall be interested to hear from you any remarks you have to make concerning these results; it would appear to us that the points are somewhat too hard. With reference to the sparking plug insulators, which you sent us, we hope to have these on test very shortly now. Yours faithfully, | ||