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).
List of materials and specifications for building primary and secondary windings for electrical coils.
| Identifier | ExFiles\Box 164\5\ img375 | |
| Date | 18th July 1938 guessed | |
| -2- 36 SWG. (.0076 dia.) tinned Copper Wire. Sec.Conn. 1¼ yds. 10/40's D.S.C. Tinned Copper Flex. ¾ yd. The two Terminal Screws K.1814A should be drilled .0468 dia. from end to end to accomodate end connections. --- Six sets of the above fittings should be built up into coils having the windings at present on test, i.e. 20,000 secondary turns 42 SWG and 300 primary turns 24 SWG, for which 6 sets of the following material will be required. Copper Wire. Primary - 24 SWG. (.022 dia.) Enamelled S.C.C. High Conductivity Copper Wire (.031 overall dia.). 48 yds. Wt. - 3½ ozs. Secondary - 42 SWG. (.0040 dia.) Enamelled High Conductivity Copper Wire (.0045 overall dia.) 2,000 yds. Wt - 4¾ ozs. Insulation - Secondary. L.P.S. Wax Paper 4.000 wide x .00175 thick. 10 yds. DW.546 - Tube - Primary Winding. 1 off. We hand you herewith DW.758 which shows the position of these parts in the case. Note that we have removed the unsymmetrical projecting end of the core and thus improved the insulation. --- The remaining set of fittings should be built up with the actual windings shown on D.CD.757. The following material will be required :- Copper Wire. Primary 24 SWG. (.022 dia.) Enamelled S.C.C. High Conductivity Copper Wire. (.031 overall dia.) 48 yds. Wt. 3½ ozs Secondary. 40 SWG. (.0048 dia.) Enamelled High Conductivity Copper Wire. (.0053 overall dia.) 2,050 yds. Wt. 7½ ozs. Insulation. L.P.S. Wax Paper 4.000 wide x .00175 thick. 13 yds. (New Piece). DW.755 - Tube - Primary Winding. 1 off. In case it is decided to test the alternative primary winding, 5 ozs. of 23 SWG.(.024 dia) Enamelled S.C.C. Copper Wire should be obtained. BY/RD. | ||