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).
Dynamo output limitations and potential solutions including modified armatures and automatic control systems.
| Identifier | WestWitteringFiles\V\December1930-February1931\ Scan083 | |
| Date | 3rd January 1931 | |
| -3- EFC1/AD3.1.31 contd. We agree with the statement in Sg{Arthur F. Sidgreaves - MD}21/E31.12.30 that with the lower resistance the cutting in point would be at 17 m.p.h. also that the output would be approximately as stated, but as previously explained, the actual number of amperes is a very variable quantity depending greatly upon temperature and battery P.D. conditions. No statement of output at varying speeds is of very great comparative value unless taken in well defined laboratory circumstances. The situation generally may be stated as follows :- We have, at the moment, owing to the limitations of size and weight, no type of dynamo which can be arranged simultaneously to be capable of giving as early a cutting in as is desired, and at the same time has a sufficiently great output at moderate and high speeds to cover the output requirements. The possibilities at present in view in obtaining such an output are as follows :- (1) The lengthened machine as recently suggested by ourselves. (2) The modified 56 coil armature as suggested above (one of which is being put in hand experimentally). (3) Some form of automatic control which enables the present standard 56 coil machine to be set to give a bigger output in view of the fact that under such control it can never be called upon to work at a high voltage with consequent high temperature. An alternative form of automatic control other than voltage operated units with which we have experimented with promising results, is, as variously suggested in our EFC4/AD2.1.30, the use of bimetal thermostat control to take effect in lowering the output of the dynamo, when the dynamo rises to a pre-determined value, in one of a few different ways. EFC. | ||