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 investigation and repair of an S.E.V. magneto from a Delage car.
| Identifier | WestWitteringFiles\I\August1922\ Scan37 | |
| Date | 10th August 1922 | |
| To R.{Sir Henry Royce} from EFC. c. CJ. c. Da.{Bernard Day - Chassis Design} ORIGINAL EPCL/T10.8.22. X.4334 - S.E.V. MAGNETO OFF DELAGE CAR. We have now completed the investigation of the above magneto as requested in Dal/M7.7.22. It appears that the high tension collector ring at the driving end must have been wrong in the first instance though it is difficult to understand how this could have come about. When the machine was repaired at the Derby works with the slip ring from another magneto, this was put on in a position exactly similar to the one taken off. Examination of the magneto showed that it had a broken secondary winding, and that the collector ring was in such a position that the sparks in the normally advanced position occurred just after the conductor had left the brush, so that the insulation at these two points was burnt. In the retarded position matters would be worse. We have had this matter rectified by advancing the H.T. collector ring through 80° so that in the advanced position the segment has just come under the brush. A break in the secondary winding at its connection to the ring has been repaired, but there appears still to be a break in somewhere else in the secondary winding, which is entirely insulated, as we cannot send any current through this with quite a high potential difference. We have now tested the magneto on our spark gaps and it gives reasonably regular sparking on twin 3mm. gaps. Contd. | ||