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).
Variability and failure issues in single field winding, third brush controlled dynamos.
| Identifier | WestWitteringFiles\G\June1921\ Scan113 | |
| Date | 23th June 1921 | |
| R.R. 235A (100 T) (S.H. 798. 10-12-20) G 2947 ORIGINAL To R.{Sir Henry Royce} from EFC. c. to CJ. c. to Da.{Bernard Day - Chassis Design} EFC8/T23.6.21. X.294 - DYNAMOS - SINGLE FIELD WINDING THIRD BRUSH CONTROL. In addition to the point already mentioned of the variability in the output of a single field winding third brush controlled machine due to varying [handwritten: bearing] of the control brush, it has also been mentioned to me that cases have been known in which dynamos controlled in this manner have failed to excite themselves, owing to the low resistance field winding and the relatively poor contact of the brushes, preventing the initial building up of the excitation. EFC. | ||