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 curves and heating tests for the Rotax A.T.12 Dynamo.
| Identifier | WestWitteringFiles\F\March1921\ Scan40 | |
| Date | 17th March 1921 | |
| To R.{Sir Henry Royce} & E.{Mr Elliott - Chief Engineer} from EFC. c. to CJ. & PN.{Mr Northey} c. to Ds. & EP.{G. Eric Platford - Chief Quality Engineer} c. to By.{R.W. Bailey - Chief Engineer} & Bn.{W.O. Bentley / Mr Barrington} c. to EWT. for R.R.Inc. ORIGINAL X.1005 - ROTAX A.T.12 DYNAMO. X4030 I have your note HS{Lord Ernest Hives - Chair}/G14.3.21. Regarding the Rotax dynamo, I attach photostat copy of curves of performances of this machine in a normally hot condition with different settings of the control brush, the sheet also showing corresponding field current curves. We have also added the curve of specified performance for comparison. The figures at the high speed end of each curve refer to the span of the field winding on the commutator in electrical degrees, the halves of these quantities referring to actual degrees. The one labelled 140° corresponds to makers' setting, and the steep curve on the left is practically plain shunt. The other curves are for the intermediate suitable positions in stages. We are now carrying out a heating test at constant output (9 amperes at 14.6 volts) with the setting the same as the curve marked 180°, which shows a maximum of 10¼ amperes, and which is fairly similar to, though earlier in cutting-in than, our curve of specified performance. We are finding out if the heating is reasonable. At the tail end of the heating test we must put the current up to its maximum or peak value, and see how much further the temperature rises, but you may Contd. | ||