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).
Comparison of the operating voltages for Lucas and Smith cut-outs under various test conditions.
| Identifier | WestWitteringFiles\D\March1920\ Scan47 | |
| Date | 16th March 1920 | |
| Contd. -3- Ck{Mr Clark}2/T16.3.20. but otherwise steady voltage, that the points at which the cut-outs operate on such a voltage are rather indefinite, particularly in the case of the Lucas cut-out which we have called B. We have since confirmed this point by trying these cut-outs over again on the battery and in a cold condition. We have found Lucas A to go on definitely at a voltage between 12.6 and 12.8 and Smith (1) and (2) to go on indefinitely between voltages of 13.9 and 14.8, and 13.2 and 13.9 respectively, but in the case of Lucas B cut-out there is something peculiar as it is possible to make it operate through quite a wide range of voltage extending all the way from 11.0 to 16.0, in spite of the fact that there does not appear to be anything mechanically wrong with this. These figures for the two Smith cut-outs differ from those previously obtained on account of the fact that, as already explained, we altered the adjustment. (We previously stated in error that there was no adjustment allowed on the Smith cut-out. We have since found that it is possible to make an adjustment). The comparativelyxx voltages to operate the Lucas cut-outs on the battery test and on the dynamo test, exhibited in the form of a table, as follows :- Contd. | ||