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).
Comparative performance report on dynamo machines and a cut-out, comparing them to models from Lucas and C.A.V.
| Identifier | ExFiles\Box 3\5\ 05-page057 | |
| Date | 12th May 1919 | |
| Contd. -2- EFC4/T12.5.19. moment is to give the comparative performance under normal conditions of one of these machines with the other machines we have tested. This will be found expressed as curves on sheet attached. It appears that with this typeof regulation, making due allowance for the extra weight, we can obtain an earlier cutting in point, and a rather quicker rise of current after that point, and for this reason it seems that electrically this, or the constant current systems tried, is the best system of control. Further particulars will be given when we have completed the full test of this machine. It will be noted that the curves are only given for one machine namely, type A.{Mr Adams} This is the larger of the two machines; the cutting in speed (cold) of the other machine is 640 R.P.M. for 12.4 volts, and there is no reason to suppose the characteristic curve to be sensibly different. The construction and insulation of the dynamos seem good with one exception, namely, that the commutators look a very poor job. We ought, however, in justice to Messrs. Smith, to state that they particularly informed us that these two machines are only hand-made, made up for us as samples, and therefore do not quite represent the production product. The finish of the whole machine of course, does not compare with that of the Lucas although it compares with that of the C.A.V. At high speeds, sparking is rather bad, especially on the control brushes, but this is a failing which is common to all three types of machine. CUT-OUT. There is a cut-out supplied as a sample which is somewhat bulkier than either the Lucas or C.A.V. This cut-out weighs 23ozs: it seems, however, a very good piece of apparatus and has Contd. | ||