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).
Test results for varnished and waxed insulated paper for ignition coil secondaries.
| Identifier | ExFiles\Box 61\1\ scan0152 | |
| Date | 4th December 1930 | |
| X6110 Ry. from EFC. c. Ry/RD. c. Sft{Mr Swift}/Mr Brock. EFC9/AD4.12.30. X6110 X.1109 VARNISHED & WAXED INSULATED PAPER FOR IGNITION COIL SECONDARIES. As referred to in Ry/RD2/W12.11.30 and Ry/RD4/W28.11.30 we have received for test - firstly a second sample of varnished insulating paper from the same source as that from which Messrs. Lucas are supplied, and secondly, two samples of waxed insulating papers of two different grades namely 242 and 745 from the L.P.S. Electrical Co. The usual tests i.e. leakage conductance and breakdown P.D. per mil have been made on these samples with the following results quoted from my assistant's report WE.62 :- "Varnished paper. The leakage conductance of this paper was negligibly small even at a temperature of 120°C. This is extremely good. The breakdown volts per mil were found to be 2,250, this being approximately the figure obtained on the previous sample tested. Wax impregnated paper grade 242. This paper was found to improve considerably as regards leakage conductance after heating at 100°C. the conductance then being also negligibly small even at 100°C. This result is much better than Symon's wax paper. The breakdown volts per mile were found to be 1770. Wax impregnated paper grade 745. This paper did not give such good results as the grade 242 but still better than the Symon's | ||