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).
Experimental record sheet for a 20/25 Dynamo detailing a 10,000-mile test.
| Identifier | ExFiles\Box 62\3\ scan0261 | |
| Date | 24th November 1931 | |
| X.No. 6005 Item No. I.24S.HC ELECTRICAL EXPERIMENTAL RECORD SHEET. Description of item :- 20/25 Dynamo. Type 48 coil, 4-4, 18 S.W.G, TP(.015"-.055") Date on. | Location. | REMARKS. | Miles reading start. | Miles covered. | Total miles. --- | --- | --- | --- | --- | --- 23 - 6 - 31 | Lab. | First of new type for second half of T series. Received from Prod^n. | — | — | — 18 - 7 - 31 | 19 G.IV. | Fitted on car for 10,000 miles test. | 1,190 | — | — 24 - 11 - 31 | " | Dynamo examined on the bench at the end of above mileage. Insulation O.K. Brush surfaces all polished and wear normal. Commutator surface brown & polished. Some blackening along edges of segments. All brushes sluggish in holders. Positive brush flexible nearly broken through, so that flexible overheated sufficiently to burn off insulating covering. Bearings O.K. CAP. 24-11-31 | 20,204 | 19,014 | 19,014 | ||