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 to Mr. Northey discussing abnormal voltage issues with accumulators, meters, and lamp bulbs.
| Identifier | ExFiles\Box 70\3\ scan0160 | |
| Date | 30th March 1926 | |
| COPY Moreton, Holly Place, Hampstead, N.W.3. 30.3.26. Dear Mr. Northey, Thank you so much for your letter of the 28th. As regards the accumulators when fully charged rising to 2.5 volts per cell, of course I entirely agree that this is absolutely normal. I also agree that Derby would naturally design ignition apparatus to cope with such condition, which of course we all know will occur; but the whole point is that in this case it is not 15 volts but 17.5 volts that we are dealing with. I have no reason whatever to think the Weston meter was at fault, especially as the zero correction was perfect. In further proof of this, I may say, that the lamp bulbs either go black or burn out after very short distances, which you go to prove that the voltage is above 15, seeing that they are rated to stand 12. to 14. Should you still doubt that there is still this abnormal voltage why not arrange to have this test made with a Weston meter which you yourself know to be correct and absolutely O.K. The result will convince you as it did myself. Concerning the suggestion of fixing a dynamo which was not capable of running at a voltage sufficiently high to maintain a certain degree of charge when the cells | ||