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).
Graph showing the volt-ampere characteristic of a standard ballast resistance made from nickel wire.
| Identifier | ExFiles\Box 168a\5\ img013 | |
| Date | 13th May 1926 | |
| AMPERES VOLTS VOLT-AMPERE CHARACTERISTIC OF R STANDARD BALLAST RESISTANCE. (25" OF 31 S.W.G. NICKEL WIRE) K.C.W. 13-5-26 | ||