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).
The green lamp scheme and improvements to the auto charge control switch for various models.
| Identifier | WestWitteringFiles\S\March1928-May1928\ Scan004 | |
| Date | 2nd March 1928 | |
| To R.{Sir Henry Royce} from EFC. c. BJ. E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. By.{R.W. Bailey - Chief Engineer} Rg.{Mr Rowledge} Wor.{Arthur Wormald - General Works Manager} c. C. CWB. SG.{Arthur F. Sidgreaves - MD} c. PN.{Mr Northey} ORIGINAL EFCl/T2.3.28. GREEN LAMP SCHEME AND AUTO CHARGE CONTROL SWITCH. We have in hand a unit applicable to the green lamp scheme. The auto charge control switch on 14-EX was the first of its type and suffered from hasty adjustment. In addition, several subsequent improvements are now available, the principal one of which is the reduction of the temperature effect by over 50% by the utilisation of a series Eureka resistance in the space on the other bobbin previously occupied by packing. This temperature improvement is equally applicable and equally necessary to the green lamp scheme and will be applied thereto. The green lamp scheme requires for its proper fulfilment the provision also of a hand switch in the dynamo field circuit, otherwise it means running on battery ignition only when charge is not required, which is not the case with the auto switch which itself virtually breaks the field circuit. In passing, a point which we think we have previously reported is that in whatever circumstances the dynamo is switched off charge it is always better for de-excitation of the machine to be brought about by breaking the field (i.e. not breaking the armature circuit first where both are broken). We have now two switchboxes (Phantom and 20 H.P.) made up each with a slight modification ensuring such first breakage of the field, and in view of the fact that one or two switchboxes | ||