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 Joseph Lucas Ltd. discussing issues with dynamo output curves and a two-way foot-operated switch.
| Identifier | ExFiles\Box 61b\3\ scan0269 | |
| Date | 23th June 1930 | |
| X4620. X6072. EFCl/AD. 23rd June, 1930. Messrs. Joseph Lucas Ltd. Well St.{Capt. P. R. Strong} Birmingham. Dear Sirs, We have to thank you for yours X/LT/5. of the 5th inst. together with enclosure and two-way foot operated switch, and regret we have not acknowledged same previously largely arising out of the fact that the writer has been away. With regard to the curve of Lucas C.5. dynamo output it appears that our standard method of taking such curves has not been appreciated because the operating voltage of the machine is not in accordance with the ampere output as given by the figures at the side, which figures have been ruled through, also a separate curve of operating voltage at much lower figures is given. When in conformity with our standard curve it is not necessary to give a curve of operating voltage because this is definitely related to the ampere output curve in the manner contained in the figures given at the side. Another way in which it is not in accordance with our standard is that all our standard output curves are taken with the dynamo indicating 80°C. on a mercury thermometer whose bulb is placed in a small copper oil bath which forms part of a copper saddle plate which strides the dynamo during test. With regard to the two-way foot operated switch, we find of interesting design but feel we can say with a fair degree of certainty that it would not be of much permanent use for the heavy currents at relatively low voltages taken by present day twin head lamps. | ||