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).
Page describing dynamo performance under various conditions, analysing performance curves and comparing it to other systems.
| Identifier | WestWitteringFiles\C\May1919\ Scan49 | |
| Date | 7th May 1919 | |
| R.R. 235A (500 T.) (S.D. 408. 26-4-17.) Bm. 2/156/13. Contd. -6- EFC1/T7.5.19. when it opposes the main field current in its action on the pole), is rapidly reduced to zero and then rapidly increases positively. A point is arrived at in each case where the control current is equal to the sum of the main and field currents and at this point, as already described, the main negative brush is inoperative. Beyond that point the negative brush is acting positively and helping to feed the control winding with current. Curves E show the out-out speed curves for six cells when the machine is connected up in various conditions (a) (b) (c) (d) and (e) as indicated on sheet F.{Mr Friese} Curve (a) gives the out-put as a plain shunt wound machine. The curves (b) (main, full, and control dotted) give the performance when the control brush. is directly connected to the negative brush and the control winding rendered inoperative. The object of this curve is because the dynamo arranged in this manner is practically the same scheme as the Trier & Martin arrangement which we shall be testing out in the near future, on a dynamo supplied to us by Messrs. Smith & Sons. They argue that their armature heating is much less than in any other system because the main current only has to traverse half the windings of the armature (at a certain speed). It will be seen by consideration of the table attached, that this applies to quite a comparable extent in the case of this Lucas dynamo. Curve (c) is a reproduction of the curve for normal conditions already given on sheet D.{John DeLooze - Company Secretary} The curve (d) gives the performance of the machine when the negative brush is ee disconnected. This represents the condition, when, for any reason, the fuse Contd. | ||