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).
Methods of controlling field resistance, comparing the Remy method with a voltage method and a ballast resistance unit.
| Identifier | ExFiles\Box 35\3\ scan 094 | |
| Date | 30th August 1926 | |
| X 4088 -2- Contd. Extract from REC 2/T. to PVR 30/8/26 X8780. Referring to the Remy method of inserting the field resistance by rise of temperature, this is an alternative method, and without going into the matter very deeply I should imagine that the results would be approximately similar to the voltage method, and either equally advantageous as compared with no control at all. It is true that we have made experiments on the Midgeley unit, but we did not make these with our own machine and I do not think the report which we have made on this would be of much interest to you in the present connection. We have, however, prepared an RR. unit on similar lines, utilising a-n RR. cutout with a specially arranged back contact. This we shall be fitting on a car very shortly utilising a standard ballast resistance for the necessary resistance to be inserted in the field, as we consider that a resistance of that type (gets higher when hotter) is more suitable for that purpose than a constant resistance. We shall be glad to let you know more about the working of this at a later date. Yours faithfully, | ||