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).
Experiments comparing Lucas and Smith standard cut-outs.
| Identifier | WestWitteringFiles\D\March1920\ Scan35 | |
| Date | 5th March 1920 | |
| To R.{Sir Henry Royce} from Ck.{Mr Clark} c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to Bn{W.O. Bentley / Mr Barrington} c. to Wor.{Arthur Wormald - General Works Manager} c. to PN.{Mr Northey} c. to By.{R.W. Bailey - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to Hs.{Lord Ernest Hives - Chair} c. to EP.{G. Eric Platford - Chief Quality Engineer} ORIGINAL X.3770 - LUCAS CUT-OUT. X.1815. X.3771. - SMITH CUT-OUT. We have made experiments on two present standard Lucas cut-outs, also on the two Smith cut-outs, one of which was received with each of the two Smith dynamos, as follows :- Taking the setting of the cut-out just as received from the makers (there is no adjustment allowed on the Smith cut-out, and the adjustment on the Lucas cut-out has recently been deleted by them so that no adjustment is possible) the cut-outs were first of all tested cold and the volts and amperes necessary to pull the cut-out into action and to allow the cut-out to drop out of contact carefully noted, with the following result :- Just operated at Allowed to drop away at Cut-out. volts. amps. ohms. volts. amps. Lucas present standard A, 13.1 .345 38.0 8.2 .21 Lucas present standard. B. 15.5 .42 37.0 8.4 .215 Smith cut-out (1) 12.2 .100 122 8.4 .063 " " (2) 13.5 .069 196 10.1 .0475 Contd. | ||