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).
Test report on a higher output armature, detailing its performance, balancing speed, and control brush settings.
| Identifier | WestWitteringFiles\S\June1928-August1928\ Scan151 | |
| Date | 31th August 1928 guessed | |
| -2- Contd. the output falls to 11.0 amperes (at 17.5 volts). A curve of output of the machine, in comparison with the representative standard output, is attached. In the cold condition (17°C) the balancing speed of the standard dynamo with higher output armature is 645 r.p.m. for 12.4 volts. The control brush setting we have given to the machine allows a good margin within the maximum permissible output, by which output we mean that output at which the machine, while running continually on the peak of that output, (at schedule voltage corresponding to ampere output) will just fall short of melting its commutator solder. We found that with the setting given, the commutation was satisfactory, the brushes being smooth and the segments clean after several hours' running. As in the case of the 20 H.P., it should be noted that this armature is of the 28 slot type to correspond with normal output 28 slot armatures about to be standardised. The machine in question has not yet been put on a car because the armature has been inserted in one of our expl. carcasses which is somewhat cut about, though of course not in regard to features which affect the output. Having found a suitable position for the control brush it is now proposed to put this armature in an otherwise standard carcass, but with the control brush position altered accordingly and to make another short test before putting the machine on one of the experimental cars. EFC. | ||