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).
Test of a 40/50 dynamo fitted with a series winding.
| Identifier | WestWitteringFiles\W\May1931-August1931\ Scan043 | |
| Date | 6th March 1931 | |
| 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. De. EY. Hs{Lord Ernest Hives - Chair}/Pgtl/AD2.6.31. 40/50 DYNAMO WITH SERIES WINDING. X6099 We have now completed a test on a dynamo fitted with a series winding, as suggested in your Rl/M9.3.31. The series winding consisted of four turns per pole of 15 S.W.G. wire and was so wound as to permit of each coil being taped up in one with the corresponding main field coil. The characteristics of the dynamo as a normal machine, were first obtained. Afterwards, the series winding was connected between the main positive brush and the positive terminal on the case, the current flowing through it in such a direction as to assist the main winding. As will be seen from the attached curves, the nett result is a very little alteration to the shape of the curve. The reason for this is because the series winding is excited as soon as current is taken from the armature, so that it assists the main winding over the whole curve i.e. it assists on the peak as well as at the tail end. The peak output is consequently increased, and to prevent overheating of the machine the control brush has to be moved so as to reduce the peak to its previous value. This causes the tail end of the curve to drop and so neutralises the tendency of the series winding to keep it up. A further test will be made with the series winding acting in opposition to the main winding. Hs{Lord Ernest Hives - Chair}/C. A.{Mr Adams} Pignatt. Print attached. | ||