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).
Improving the temperature compensation of the main shunt coil for an auto switch.
| Identifier | ExFiles\Box 59\1\ Scan272 | |
| Date | 18th February 1928 guessed | |
| -4- Contd. Therefore, as the auto switch stands at present, the principal requirement in the direction of greater perfection would appear to be the temperature compensation of the main shunt coil. We know that this can be partly effected by the use of an external series resistance of zero temperature coefficient wire but every step taken in this direction means we have got to use more amperes and more watts for excitation, and we do not want to come back to that condition where the resistance must be put on as a separate unit. The only maxm possibility would appear to be, and this would appear to be a good possibility, to put this series resistance inside the normal field resistance on the back bobbin, i.e. nearer to the core. On consideration of the matter this arrangement for the mdofication of partial compensation appears rather hopeful, and further consideration is being given to this. At least we shall be utilising winding space which is not at present used and introducing the resistance coil in a space where the watt loading is at present well under what it might be. EFC. | ||