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 endurance testing of a new type Lucas cutout with a duplex magnetic circuit.
| Identifier | WestWitteringFiles\G\June1921\ Scan114 | |
| Date | 24th June 1921 | |
| To R & E from EFC c. to CJ. & FN. c. to Bn.{W.O. Bentley / Mr Barrington} & By.{R.W. Bailey - Chief Engineer} c. to Ds. & EP.{G. Eric Platford - Chief Quality Engineer} c. to EWT. for R.R.Inc. X.4349 - NEW TYPE LUCAS CUTOUT WITH DUPLEX MAGNETIC CIRCUIT. We yesterday tested this cutout. By means of a revolving contact, we caused the field circuit of the dynamo with which the cutout was operating to be made and broken periodically so that the battery was connected and disconnected from the dynamo by the cutout. We ran in this way for 5¾ hours at a rate of 100 breaks per minute, so that the cutout contact was made and broken altogether about 34,500 times. The number of amperes broken by the cutout would be rather more than the two or three amperes under normal working conditions, because the main current at the time the main field circuit was broken would reverse quickly, before the shunt coil magnetism had time to die away. Therefore, though we do not know this definitely, we think a current of 8 or 9 amps. was broken by the cutout at each break. Certainly the flash was greater than in normal working. The cutout showed no signs whatever of failing to function. The only thing that happened was that the large contact point became a little hollow. It was not actually pitted, so that the electrical contact, although being made later in the travel than at first, was still quite good. Contd. (upside down text at bottom) R.R. 285A (100 T) (S.H. 798 10-12-20) C 2947 | ||