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).
Decision to revert to a double pole push button switch and the related timing of its circuits.
| Identifier | WestWitteringFiles\T\November1928\ Scan085 | |
| Date | 14th December 1928 | |
| To R.{Sir Henry Royce} from EFC. u. RJ. E.{Mr Elliott - Chief Engineer} c. Ev.{Ivan Evernden - coachwork} Wor.{Arthur Wormald - General Works Manager} ORIGINAL EFC2/T14.12.28. S.S. STARTER PUSH BUTTON SWITCH. X76552 We are disappointed in your decision to revert to a double pole push button switch together with an overlap of the timing of teazer circuit break and main current make. The next switches (third and onwards) have been instructed and are being made to the gaps contained in your Lec.2620 for use with double pole push button switches. In the meanwhile, however, we have the first two switches operating satisfactorily with single push button switches and with a carbon contact interval gap, i.e. .015" delay between the main carbon make and the breaking of the teazer circuit carbons. A point arises out of the timing given on your Lec.2620 which calls for the main switch carbons to make before the teazer circuit silver contact breaks. When the main circuit is made the voltage across the teazer circuit falls to zero and it would appear that in these circumstances we could dispense, at least experimentally, with the carbon break of the teazer circuit, a point which was referred to some time back in connection with the electrical interlocked switch. No difficulty appears to arise in actual working with a carbon interval gap due to the fact that very momenterily the only current flowing is the current through the main switch operating coil and motor operated contact - the time is too short to have any effect on the motion or position of the armature. EFC | ||