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).
Tests carried out on a dynamo auxiliary field winding.
| Identifier | WestWitteringFiles\W\September1931-November1931\ Scan003 | |
| Date | 2nd September 1931 | |
| ORIGINAL To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Pgt. c. Sg.{Arthur F. Sidgreaves - MD} c. Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} c. Da.{Bernard Day - Chassis Design} Ev.{Ivan Evernden - coachwork} Hs{Lord Ernest Hives - Chair}/Pgt1/AD2.9.31. X6099 X6126 DYNAMO AUXILIARY FIELD WINDING. We have now carried out some tests with the series field winding excited by the head lamp current. In these tests we started by using the series winding, of 4 turns per pole of 15 S.W.G. wire, which was used in the previous series winding experiments. In taking the place of the two-rate charge scheme, the series winding dispenses with the field resistance unit. As, however, the output of the present standard armature normally is too high - rising to 16 or 17 amperes when running on the battery alone, and reduced for day running to about 12 amperes by the field resistance of the two-rate charge scheme - the results given are those obtained using another type of armature. An earlier type of armature was obtained which was found to naturally give a suitable output when running on the battery alone. Tests were made supplying the winding from the battery through first 36 watt lamps and then 60 watt lamps. Details of the output curves obtained, and shown on the attached sheet, are as follows :- 1. Output of the machine without the series winding connected. 2. Output obtained with series winding supplied through 36 watt lamps. 3. Output obtained with series winding supplied through 60 watt lamps. The dotted curve shows the output of the present standard machine as used in conjunction with the two-rate charge scheme under conditions corresponding to those of curve 3. Generally speaking, the effect of the series winding used in this manner, is to give an increase in output over the whole curve, with rather more on the peak than at the tail end, so that the shape of the curve is not advantageously altered. | ||