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).
Recommendation to remove carbon contacts from the Phantom II starter system push button switch.
| Identifier | WestWitteringFiles\U\May1930-July1930\ Scan067 | |
| Date | 30th May 1930 | |
| To R.{Sir Henry Royce} from EFC. c. Sg.{Arthur F. Sidgreaves - MD} c. By.{R.W. Bailey - Chief Engineer} E.{Mr Elliott - Chief Engineer} c. Da.{Bernard Day - Chassis Design} Wor.{Arthur Wormald - General Works Manager} ORIGINAL EFC/AD30.5.30. X.6015. PUSH BUTTON SWITCH WITHOUT CARBON CONTACTS. We recommend that the present push button switch on the Phantom II starter system would be definitely better in the absence of carbon contacts. In normal operation only the small current of the hold off coil has to be broken by the push button switch. In operation when the engine does not start the main switch exciting current has to be broken by the push button switch, but the inductive effect is minimised by the presence of the non-inductive resistance in parallel with the main switch winding. The worst case is when either as a result of spasmodic application of pressure to the button, or as a result of pinion engaging to wheel not taking place, the main actuating current is broken at this switch. The switch as at present, permits of partial but ineffective operation of the starter should the push button not be pressed decisively. Quite an appreciable portion of the total applied pressure is absorbed as pressure operating on the carbon contacts. It appears to us | ||