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).
Comparative test report on two different types of ignition coil impregnating wax.
| Identifier | ExFiles\Box 165\5\ img100 | |
| Date | 31th May 1933 | |
| 86113. E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Wst. c. to By.{R.W. Bailey - Chief Engineer} c. to Sft{Mr Swift}/Mr.Brock. Hs{Lord Ernest Hives - Chair}/Wst.8/MA.31.5.33. Ignition Coil Impregnating Wax. We have recently received from the Telegraph Condenser Co.Ltd., a sample of wax which they have developed for impregnating their condensers. Special features of this wax are high melting point and high resistances. We have carried out comparative tests in the laboratory between this T.C.C. wax and standard R.R. white paraffin wax now used on production for impregnating ignition coils, and the following results were obtained:- T.C.C. Wax. Insulation resistance at - 60°C. 4,200 megohms. 80°C. 3,980 " 100°C. 1,088 " This wax has a melting point of 86°C. approximately. R.R. White Paraffin Wax. Insulation resistance at - 60°C. 222 megohms. 80°C. 140 " 100°C. 106 " The melting point of this wax is 56°C. It will be seen therefore that the T.C.C.wax is considerably superior in its insulation characteristics and melting point for our ignition coil work, than the ordinary plain white paraffin wax. We are arranging to obtain a few standard coils impregnated with this wax for tests. Hs{Lord Ernest Hives - Chair}/Wst. | ||