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).
The examination of a dynamo from chassis 89-HC with excessive output.
| Identifier | ExFiles\Box 70\3\ scan0321 | |
| Date | 27th October 1927 | |
| X8783dc To BY.{R.W. Bailey - Chief Engineer} from EFC. c. Mr. Brock. EFC5/T27.10.27. DYNAMO NO.AT.55 EX CHASSIS 89-HC. Concerning this machine I have received the following report from my assistant :- "The Complaint concerning this machine was that the output was too high; 13 to 14 amperes. From an examination of the machine, there is little doubt about the position of the control brush being the cause of excessive output. This position corresponds to the early setting of 120° from the main positive brush. The solder at the commutator connections appeared to have just melted, some of it having been thrown. The positive and control brushes were blackened and pitted, but the negative brushes were well bedded and fairly well polished. Carbon dust was found to have bridged the insulation on the positive brush holder causing a breakdown when tested on the A.C. mains. The outer control brush was sluggish in its holder, but in other respects the machine appeared to be O.K." The dynamo is handed to BY.{R.W. Bailey - Chief Engineer} herewith. EFC. | ||