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).
Bench tests of production type ignition coils with different secondary insulations.
| Identifier | ExFiles\Box 69\1\ scan0310 | |
| Date | 11th February 1930 | |
| E.7.C. X, 8710 Date 11-2-30 Ref NO. WE4. X.NO. 8710 Present production type ignition coils wound to drg D72428. We have now completed a series of bench tests on two of these coils NOS. L.I.1 with varnished paper secondary insulation and L.I.2. with paraffin waxed paper insulation. Both of these coils were tested to our new general schedule of per-formance and the results, entered on the requisite form are attached to this report. In the case of L.I.1 this coil - functioned OK throughout the test but broke down on the final breakdown test comparatively early we consider. L.I.2. broke down very quickly on the preliminary intensive test. In both cases the breakdown was due to a short circuit on the lower secondary layers in the case of L.I.2 most definitely so. The electric-al performance was comparatively good but not much improvement over the old standard D71650 coil. It will be seen that in spite of the flat foundation afforded | ||