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).
Particulars of construction for a standard ignition coil to D.72503.
| Identifier | ExFiles\Box 164\5\ img035 | |
| Date | 30th January 1931 | |
| X 6058 30.1.31. X.6058. PARTICULARS OF CONSTRUCTION OF STANDARD IGNITION COIL TO D.72503. Core built up of Swedish iron wires 24 S.W.G. approx. 5 ozs weight. Core insulated by paxolin tube D.72455. Primary wound direct on this tube 298-10 turns of 22 S.W.G. S.C.C. enamelled wire. Primary baked and vacuum impregnated with sterling 81.E varnish. Primary insulated with paxolin tube D.72454 which forms the base for the secondary winding. Secondary winding 18,000 turns 42 S.W.G. enamelled wire. Joined to primary by 10/40 flex. No. of layers 60. Each layer of secondary insulated with 3 turns of .00075" paraffin waxed paper. Secondary winding covered when completed with .005" oil silk 1/2 lap. Finished coil impregnated with paraffin wax. | ||