Coil design, discussing primary winding temperature, resistance, and suggestions for improvement.
| Identifier | ExFiles\Box 164\5\ img171 | |
| Date | 4th April 1933 | |
| -2- Hs {Lord Ernest Hives - Chair} /Wst.9/KT.4.4.33. cont'd. {John DeLooze - Company Secretary} whole coil so that the distance between the core and the coil case is at least 1/8". It might be preferable to manufacture this pedestal moulding in some other insulating material having less leakage losses at high temperature than Bakelite. We are carrying out lab. tests in this respect. (4) The primary winding has a large temperature rise and we consider it would be an advantage from the point of heat dissipation if the primary layers, other than the first, were increased in length, the step between layer to layer being reduced. This should result in one layer less for the same number of turns, and the whole winding would have a bigger area of contact with the case for the purposes of heat dissipation. The primary resistance as measured is rather low being 3.2 ohms. as against our original estimation of 3.6 ohms. We consider that the primary resistance should be increased to at least 3.6 ohms. preferably 4.00 ohms. If advantage was taken of the reduction in layers due to a smaller step between the layers, it should be possible to accomodate another 40 or 50 turns. In any case we should endeavour to get in the extra turns, as the standstill primary current is high. We do feel that it would help the design considerably in many directions if the length of the whole coil was increased. We should be glad if you would kindly examine our suggestions and arrange for further experimental coils to be instructed. 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).