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).
Primary winding and ballast resistance for ignition coils.
| Identifier | ExFiles\Box 69\1\ scan0084 | |
| Date | 16th May 1928 | |
| Hs{Lord Ernest Hives - Chair} V8710 To EFC. BY/RD1/MLJ16.5.28. RECEIVED MAY 16 1928 IGNITION COILS. In reverting to 300 turns of 22 S.W.G. enamelled and S.C.C. for the primary winding the question of Ballast Resistance naturally arises, I should suggest using the same ballast resistance that we previously used with this primary as we know how this combination will behave, but you may prefer to retain the double valve ballast. Will you please let me have your recommendation as soon as possible. BY/RD. | ||