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).
The merits of a twelve-volt electrical system versus a six-volt system.
| Identifier | ExFiles\Box 168b\2\ img042 | |
| Date | 26th August 1920 | |
| Contd. -2- R17/G26.8.20. by the weight of connections for the double current. I agree with you that the connections and cables should be four times as heavy for equal percentage of loss. The action of the apparatus would, to my mind, be in favour of twelve volts, as the resistance of the brush contacts and all other parts would affect a six volt installa- tion more than a twelve volt one. So far as we have experi- enced there is no corresponding disadvantage of the twelve volts. We should think that what is gained in the smaller quantity of insulation on the coarser wires of the dynamo and motor be balanced in the increased percentage of voltage losses in the carbon brushes etc. One would concluded from Mr. Bijur's conversa- tion that they are not yet in a position to supply a satisfac- tory twelve volt installation for the R.R. cars at present being constructed in America. As regards learning something of his apparatus, we shall be extremely pleased to get hold of a "Marmon" car, and after it has been to the works and been tested, it could be brought here and exchanged with the "Buick" car, our experience and examination of which has proved extremely useful to us. R.{Sir Henry Royce} | ||