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).
Table of final windings for the green lamp switch and auto charge control switch.
| Identifier | ExFiles\Box 59\1\ Scan311 | |
| Date | 14th April 1928 | |
| X4008 14.4.28. TABLE OF FINAL WINDINGS FOR GREEN LAMP SWITCH AND AUTO CHARGE CONTROL SWITCH. Armature bobbin. | Pivot bobbin. R.R. 12 volt Green lamp Switch. Fill up with 28 S.W.G. D.S.C. Copper wire. Fill up with 24 S.W.G. D.C.C. Eureka wire. R.R. 12 volt Auto Charge Control Switch. As above, with 28 S.W.G. D.S.C. Copper wire. As above, but one layer less of 24 S.W.G. D.C.C. Eureka wire. Field resistance winding 12 feet of 30 S.W.G. D.C.C. Eureka wire. R.R. U.S.A. 6 volt Auto Charge Control Switch. Fill up with 24 S.W.G. D.S.C. copper wire. Fill all but two layer with 24 S.W.G. D.C.C. Eureka wires in parallel. Field resistance winding 6 feet of 26 S.W.G. D.C.C. Eureka wire EFC. Revised 12.6.28. | ||