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).
Analysis of an alternative electrical wiring scheme (Scheme 2) and its effects on the dynamo and charge circuits.
| Identifier | ExFiles\Box 163\6\ img031 | |
| Date | 16th April 1930 guessed | |
| -2- to the dynamo side of the field fuse as in present standard. The charge reducing resistance is connected as a shunt across the distribution box terminals to which the wires 1 and R are connected. It will be seen that the effect of Scheme 2. as compared with Scheme 1. will be :- (a) The charge reducing resistance which is cut-out only when the head lamp switch is put on will now be inserted in the armature positive circuit. It will be of a suitable smaller value accordingly. The watts dissipation will be of the same order of magnitude as previously, and the cutting in point of the dynamo will be less affected than in Scheme 1. i.e. it will not be so late in speed. (b) Dynamo output will not be produced in the first or M & B position of the charge switch because the field will not be connected. (c) The extended armature contact is retained. (d) The connection of the position end of the cut-out is such that this connection is subject to and protected by the field fuse in regard to a short circuit to earth, though the likelihood of such is, of course, very small. It is thus considered that the arrangement is an improvement over Scheme 1. In regard to the switchbox it will be seen that this is not altered except as regards the marking, in which the present 1 becomes R, the present R becomes 2, and the present 2 becomes 1. Markings on the distribution box of course being unaffected because we want to keep this to correspond with the dynamo terminal markings. Instructions are being given for modification of the system at present being arranged on 24-EX to bring about this result simply by changing connections in the following manner :- | ||