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).
The receipt and testing of two different Smith cutouts for experimental cars.
| Identifier | WestWitteringFiles\F\April1921\ Scan88 | |
| Date | 18th April 1921 | |
| To R.{Sir Henry Royce} & E.{Mr Elliott - Chief Engineer} from EFC c. CJ. & PM. c. Ds/ & EP.{G. Eric Platford - Chief Quality Engineer} c. Ey. & Bn.{W.O. Bentley / Mr Barrington} c. EWI. for R.R.Inc. ORIGINAL X.3771 - SMITH CUTOUTS. - We have recently received from Messrs. Smith, in accordance with an order placed with them some time ago for Smith dynamos and cutouts to be run on experimental cars, two of their cutouts made up with the R.R. type of fuse holder and clips for the field fuse. Further, one of these cutouts is made up with a shunt winding all of copper, and the other with a shunt winding whose resistance is composed half of copper wire and half of Eureka wire. This was in accordance with our contention that a cutout would be better if the temperature range between cold and hot operation were not quite as great, but in any case, owing to the bulkiness of the Smith cutout, this does not apply so strongly to this instrument, and Messrs. Smith were of the opinion that it was not necessary. It is for this reason that they have submitted to us two cutouts, one of which has this modification and one of which has not. We have now made tests of these two cutouts on the bench in order to ascertain how nearly these come within our specification of cutout operation and how consistent they are in their operation from time to time, as we have often found, though not always been able to explain why, that the point of operation of a cutout appears to vary from time to time quite apart from understood causes, such as temperature Contd. | ||