Preliminary tests on the new type J.3 and Peregrine ignition coil.
| Identifier | ExFiles\Box 164\5\ img156 | |
| Date | 1st September 1932 | |
| X6017 To R. {Sir Henry Royce} from Hs {Lord Ernest Hives - Chair} /Wst. c. Sg. {Arthur F. Sidgreaves - MD} Hór. {Sir Henry Royce} c. S. Ds. c. Hy. {Tom Haldenby - Plant Engineer} Hdy. {William Hardy} NEW TYPE J.3 AND PEREGRINEExperimental Bentley car never produced / Aero Engine IGNITION COIL We have now conducted some preliminary tests on the above coil which is the design with outside primary running without a ballast resistance. The results, considering this is the first coil made up, were very satisfactory, the heating losses being very reasonable and the efficiency nearly as good as the Delco Remy and Lucas, this efficiency being based on the average primary current and the output secondary voltage. The tests we have carried out were first made with the magnetic circuit completed on the outside of the coil by means of laminated slate. We do not consider this to be very satisfactory in view of the inadequate path for the lines of force and we have tried the more logical method of placing a straightforward laminated iron sheath round the coil itself. This allows a much simpler construction and is uniform practice with other coils of repute of this type. An additional advantage was gained by using the iron sheath in the performance of the coil in that approx. 8% increase in secondary voltage was noted with an additional increase in the primary inductance resulting in less current consumption. We therefore recommend that we adopt this method of completing the magnetic circuit round the outside of the coil. Hedge-hogging the ends of the coil, while an admirable way of completing the magnetic circuit, introduces difficulties due to the fact that the iron core is at a high potential and by hedge-hogging, the insulation difficulties would be considerable owing to the fact that the low tension primary is on the outside of the coil. In view of the satisfactory result of these tests we are proceeding with two further coils made up complete in their cases for further test on the bench and in conjunction with the new double breaker PeregrineExperimental Bentley car never produced / Aero Engine distributor designed to run with this coil. Hs {Lord Ernest Hives - Chair} /Wst. | ||
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).