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).
Technical analysis of the interaction between battery and dynamo voltages within an electrical charging system.
| Identifier | ExFiles\Box 70\3\ scan0165 | |
| Date | 1st June 1926 | |
| EFC/T1.6.26. -4- Contd. the superior separation, has slightly increased, but this is a relatively small proportion of the whole, and does not lead to so much difference in the terminal P.D. of the battery on charge as might be supposed. I have stated that there is no reason to doubt the observations of Mr. Sidney's son, but his deduction therefrom is in error. The voltage of the electrical system is a joint function of the battery and dynamo, but the battery itself exerts the main control, and no other dynamo feeding the same current to the same battery through the same leads can possibly put up a different available P.D. at the distribution board. I suppose we are so used to thinking of lighting mains at fixed voltages that people think of these particular dynamos working at certain voltages and that they have only to have another dynamo operating at another voltage to keep the voltage of the system down. Of course, it would be possible to readjust the machine to give a smaller current (say half rate), but the E.M.F. of the battery at such half rate of charge would still rise very nearly to 16.8 volts (not quite, because there is not so much gas to get rid of), and the P.D. of the system to, say, 17 to 17 1/2 volts. A supply of current at a voltage not capable of exceeding 15.5 would never completely charge the battery, because to do so the battery E.M.F. must rise finally to Contd. | ||