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).
Modifications to a vibrator regulator and auto switch to prevent low-frequency vibration.
| Identifier | ExFiles\Box 59\1\ Scan338 | |
| Date | 11th November 1927 | |
| -6- Contd. running into vibrator regulator action previous to the change of the negative end of the shunt coil, we should have run into the low frequency vibration trouble already referred to. Having [handwritten: moved] modified this connection to the earthed side of the cutout will prevent the occurence of this phenomenon, whatever the magnitude of R, and that was given as an additional reason for the change, appearing fully to justify [handwritten: the] our loss of protection referred to. We stated that we had an idea by which we hoped to be able to do this, and this was to give the additional stimulus to the separation of the points just at the first instant of break while the voltage of the dynamo would be rapidly falling, by winding the whole of the value of R additively to the ordinary shunt coil. We said we could see no reason why this should not work satisfactorily and later, on trying this notion, we found as reported in EFC3/T11.11.27, that it worked satisfactorily. The elimination of the tendency to vibrator regulator action was completely effected. Further consideration was then given to the connections of the positive end of the auto switch shunt coils and cutout. It was pointed out that the low frequency vibration referred to would occur with the Midgley type of auto switch if it was attempted to use a high resistance. Further, the advantages of the auto switch in giving [strikethrough]unmistakeable[/strikethrough] audible and visible signs of an open battery circuit were made clear. At this time we asked Mr.Walker | ||