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).
The test results of various ignition coil insulating papers.
| Identifier | ExFiles\Box 69\2\ scan0022 | |
| Date | 10th October 1930 | |
| X8712. By from EFC. c. Sft{Mr Swift}/Mr.Brock. EFC4/ADL.10.10.30. X.1109. IGNITION COIL INSULATING PAPERS X.8712. FOR SECONDARY WINDING INSULATION. As requested in Ry/RD2/W24.9.30 we have tested the various samples of paper therein referred to together with a further sample of plain untreated white paper which Mr.Brock dried and impregnated with paraffin wax. The tests consisted of :- (a) Electrical breakdown test on the H.T. transformer. (b) Leakage conductance tests at various temperatures. The thickness of the various papers vary from .0005" to .0015" so for comparative tests in the (a) case a number of thicknesses of each paper was put together to make up .0045" for the test. In the (b) case the test thicknesses were similarly made up to .017". With reference to the actual tests, my assistant's report WE.50 reads as follows :- "With reference to (a) the following figures were obtained at atmospheric temperature :- Paper tested. Peak breakdown Ditto per mil. volts for .0045" Std. wax/papered 8440 1874 Plain white paper impregnated by EJB. 7700 1710 with paraffin wax. Plain paper unwound from coil after the 6450 1433 coil had been wax impregnated. Delco-Remy wax paper 6680 1484 taken off condenser. As regards the conductance test (b) the following results were obtained :- | ||