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 analysis of a Rotax dynamo, comparing its output curves, voltage, and current to specifications.
Identifier | WestWitteringFiles\G\October1921\ Scan25 | |
Date | 27th October 1921 | |
Contd. -2- EFC1/T27.10.21. it will be interesting to note the effect of exchanging this Rotax dynamo for the Lucas, which can now be done almost immediately. Regarding the output of this machine with the brush setting altered so that, running on the peak output, our maximum specified temperature is not exceeded, please find attached copy of photostat curves of output of the machine in this condition, together with added specified performance of output, also curves of field current. It will be seen that whereas the starting cold and hot outputs are sensibly lowered, that in the hot condition can still be said to comply with our specification. Although it falls below it at one point, it can be virtually made to comply by altering the drive ratio and thus shifting the curve bodily to the right. We consider, owing to the fact that the area of the current speed curve in the early stages is considerably larger than that of our specified performance, we can say that this curve of output complies. It is no doubt a very satisfactory curve, giving a large volume of current in the quite early stages and a rather smaller charging current at touring speeds. The machine in the cold condition attained a cutting- in voltage of 12.4 at 445 r.p.m. In the hot condition a cutting-in voltage of 13.6 was attained at 525 r.p.m. Thus it will be seen that in this respect the machine is somewhat earlier than the four-connection machine of the standard H'K' S2FV (100 L) (2 H' 188' 10-JS{Mr Johnson's Secretary}-50) C' 5011 | ||