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).
Experimental spirally wound iron core for an ignition coil.
| Identifier | ExFiles\Box 69\1\ scan0308 | |
| Date | 29th January 1930 | |
| X8710 RHC.{R. H. Coverley - Production Engineer} from EFC. c. Mr.Brock. c. EV.{Ivan Evernden - coachwork} EFC3/AD29.1.30. X.6013. IGNITION COIL WITH EXPERIMENTALLY X.8710. SPIRAL WOUND IRON CORE. A type of core construction which may have certain advantages in manufacture, is that of a flat sheet of iron duly surface insulated and spirally wound up like a blind on a roller, the ends being provided with flat radially split washers to provide for the spreading of the magnetic flux at the end. We have made up such a core, and we find this enables us to obtain about 30% more iron in the same space as that occupied by the present standard longitudinal wires. Will you please arrange to have this core wound as an experimental coil with primary only in the first instance to drawing D.72428. From preliminary measurements of the inductance of the primary winding an appropriate reduction in the number of primary turns will be arrived at. EFC. | ||