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).
Reduced charge switching and its interconnection with the headlamp switch.
| Identifier | ExFiles\Box 163\6\ img007 | |
| Date | 8th January 1930 | |
| X6016. To E.{Mr Elliott - Chief Engineer} from EFC. EFCL/ADL8.1.30. X.7730. REDUCED CHARGE SWITCHING X.6016. We have not yet received from you a copy of your memo to R.{Sir Henry Royce} in which it was your intention to summarise the joint recommendation of yourself and ourselves regarding a reduced charge switching scheme, namely to the effect that this reduced charge switching should be interconnected with the head lamp switch. You will remember that we also suggested the possibility of a one-way interconnection only so that it would be possible to have full charge with head lamps off, but it would not be possible to have the head lamps on without full charge. It was however, considered advisable to recommend a full interconnection and you were going to look into this matter on your return to W.W. In the meanwhile we have ourselves looked into the possibility of this and find that it is readily possible as follows :- The floating plunger of the side and head lamp switch in the first 'on' position connects the positive supply (6) from the battery to the side lamp positive (5), and in the second 'on' position connects the positive battery supply to the head lamp positive (4). Actually it will be seen that two positive contacts (6) from the battery are in contact with the floating conductor in the second position whereas only one is necessary. If therefore, we separate the further portion of the battery positive conductor (6) from the battery positive, extend it a short way along the bakelite support, pass a connecting bolt through the bakelite base of the switch, and provide a new contact (2) on the back, we have an additional contact available on the head lamp switch side which is only in contact with the battery positive when the switch is in the head lamp position. To this new contact would be attached the dynamo field wire. It would, however, be connected to the old contact (2) via the necessary field resistance so that the ordinary charging switch would only give the reduced charge until the head lamp switch was put in the 'on' position. This is precisely as required. Another point which has arisen in connection with switchboxes since the inception of Phantom II should, we consider, now be taken into consideration in the new design of switchbox which may be produced. | ||