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).
Technical memorandum discussing potential modifications to a 'Green Light Scheme' unit to adjust its voltage operation.
| Identifier | WestWitteringFiles\T\2July1928-December1928\ Scan257 | |
| Date | 11th December 1928 | |
| EFC. } FROM R.{Sir Henry Royce} ~~HS.{Lord Ernest Hives - Chair}~~ ~~BY.{R.W. Bailey - Chief Engineer}~~ ~~C. to BJ. WCR~~ ORIGINAL re. GREEN LIGHT SCHEME. R 1/M11.12.28. ~~X 9740~~ X 4040 This unit is still to be connected to C. terminal provided we can get it to work,because we cannot find a better scheme than that shewn in E's Lec. diagram . I believe it will work alright if we make the voltage necessary for holding in nearer like the pull on volts. (1) We can do this by shortening the stroke to between .010" and .015" - i.e. tungsten points only break by 10/1000 to 15/1000. (2) We can also get it nearer by a longer air space. Perhaps it would be safer to have some brass pins or rivets on the face of the armature so that the air space must be .015" to .020". Test as made and you will probably find that if 16 is the pull on voltage, it will be necessary for the voltage to fall to below 8 before the armature comes away. Probably it would work quite reliably if it were made so that it broke contact at about 10 or 12 volts. One thinks that directly the switch breaks, the exciting circuit of the dynamo the voltage must fall extremely low for a fraction of a second. The oscillagraph might shew the voltage. We are open to suggestions if you can see anything better. R.{Sir Henry Royce} | ||