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 and specifications of a Delco ignition coil taken from a Packard car.
| Identifier | ExFiles\Box 127\1\ scan0045 | |
| Date | 1st November 1917 | |
| R.R. 235A (500 T) (S.D. 408. 26-4-17.) Bm. 2/156/13. X.435 1.11.17. PARTICULARS OF DELCO COIL FROM PACKARD CAR Secondary winding consists of 44 1/2 layers of .005" enamelled wire. 325 turns per layer. Total 14300 turns 2 5/32" overall dia: Primary winding consists of 4 layers of .032" D.S.C. wire, 63 turns per layer. Total 252 turns. (step up ratio 56.75) Between every layer of the first 20 layers of secondary a piece of oiled paper .0035" thick, after every fourth layer has two pieces of paper and the last two layers have three. Each layer of secondary is within .375" of the end of the insulation. Insulation between Primary and core consists of a Manilla paper tube .025" thick .685" outside diameter. Insulation between primary and secondary, two layers of .0075" Manilla paper. Length of coil, core and insulation 2.650" (inside flanges). Core 110 lengths of .050" x 2.650" iron. Top of coil insulated with three layers of Empire Cloth .010 thick. Overall dia: 2 5/32" The inside end of Sec: taken through flange to earth for connection. | ||