Design specification for an experimental coil, detailing the primary and secondary windings, iron circuit, and casing.
| Identifier | ExFiles\Box 164\5\ img065 | |
| Date | 4th April 1931 | |
| Hs {Lord Ernest Hives - Chair} /HEW2/AM.4.4.31. contd. -2- R. {Sir Henry Royce} is keen to delete the ballast if at all practicable as is done on Delco Remy and we consider we ought to try an outside primary coil designed accordingly. We submit below a design of coil which we consider could be tried experimentally without a ballast resistance. Primary 400 turns of 23 S.W.G. S.C.C. enamelled wire Length of mean turn 6.00" Approx. resistance cold 3.60 ohms. Watts dissipation 40.2 Secondary. 20,000 turns 42 S.W.G. wire Iron circuit. by winding up a long strip of Core dia. .500" made spiral construction of "Lohys" iron .012" thick. Over the outside of the primary 10 turns of "Lohys" also spirally wound. A 3 B.A. iron bolt through centre could be securing bolt and winding mandril for winding up the core. Case. Thin gauge iron with a joint or seam. The case could be ventilated with advantage at the top. Only one paxolin tube would be used - that over the core. Two or three turns of oil silk over the primary would insulate it from the outside iron sheath. Hs {Lord Ernest Hives - Chair} /HEW. | ||
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).