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).
Letter regarding the high voltage output of the New Phantom's generator and its incompatibility with standard 12-volt light bulbs.
| Identifier | ExFiles\Box 71\2\ scan0013 | |
| Date | 11th December 1925 | |
| OY4/E/121125. COPY. December 11.1925. Mr. Claude Johnson, Rolls-Royce Ltd., London, England. Copy for attention of Works Committee. Dear Sir, re. 12 volt Generator. We find that the New PhantomCodename for PHANTOM I car will not successfully use the standard American 12 volt light-bulb. These bulbs are marked 12 - 16, and actually will not stand more than 16 volts. We find the generator on the Phantom gives 17 volts, (13 amps) at the peak, 20 m.p.h. charging a standard Exide 12 volt battery 6XX-13-1. This is higher than we have hitherto used on any 12 volt system. So far, we have found it necessary to run without charging at night, to avoid burning out the lamps. We have not yet found any 12 volt lamps which will stand the higher voltage. We suggest that it would be advisable, at least for this country, to rudeuce the maximum charging rate of the Phantom generator to correspond to a maximum voltage not exceeding say 15.5. Yours very truly, (Sgd). Maurice Olley. MO/E | ||