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).
Performance comparison of a standard machine against a Lucas machine, detailing potential improvements.
| Identifier | WestWitteringFiles\V\2January1931-April1931\ Scan078 | |
| Date | 3rd March 1931 | |
| EFC/ADSO.3.31 contd. -5- B. is the curve to be directly compared with I. of our standard machine and shows a somewhat superior performance. It has a slightly higher and rather later peak and about 1 1/2 amperes more current at all speeds above about 2,000 R.P.M. The slope, however, of the curve, representative of the falling away of current with speed is the same as in our own machine. The comparison of the two machines is certainly very instructive. We know from various tests made from time to time that we can comparatively easily improve the position of our curve above say 1800 R.P.M. in the way shown by the Lucas B. curve, by utilising a larger air gap ( or trailing poles) with a corresponding readjustment of the brush positions, the final result being, of course, for the same temperature rise. In doing this, however, we put up the cutting in point approximately 100 revs. later. The fact that the Lucas cutting in point is, in spite of the greater output at speed, equally as good as our own, is due to the superior arrangement of the armature, permitting of the hand winding by which virtually both more iron and more copper are effective. E.F.C. EFC. | ||