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).
Specifications and fitting of a green lamp switch unit to experimental chassis.
| Identifier | WestWitteringFiles\S\March1928-May1928\ Scan145 | |
| Date | 1st May 1928 | |
| R.{Sir Henry Royce} from EFC. g.{Mr Griffiths - Chief Accountant / Mr Gnapp} to BJ. E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} By.{R.W. Bailey - Chief Engineer} c. Wor.{Arthur Wormald - General Works Manager} PN.{Mr Northey} ORIGINAL. EFC2/T1.5.28. GREEN LAMP SWITCH UNIT. X.4040. Herewith we send you a diagram of the green lamp switch unit. The winding on the pivot bobbin is now manganin in series with the copper winding on the armature bobbin. The resistance ratio is 5 manganin to 1 copper, and the ampere turn is 4 manganin to 13 copper. In addition to the green lamp switch unit which we have reported to you as having been fitted to 12-EX, a second switch unit and lamp have now been made and tested, and are being fitted to experimental chassis 9-G3. Some data concerning this are given in my assistant's report AD.6. of which we attach a copy. EFC. | ||