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).
Proposed modifications to the switchbox and dynamo charging system.
| Identifier | ExFiles\Box 163\6\ img193 | |
| Date | 9th July 1932 | |
| - 2 - E.1/HP.9.7.32. charge to be on all the time in which both resistances would be in series with the field. Head, Side & Tail. Ignition & Winter charge. Side & Tail. Ignition & Summer charge. OFF OFF The present charge position of the ignition switch would be replaced by a winter daylight running charge in which one of the resistances would be cut out. The side and tail position of the lighting switch retains the last mentioned resistance in the field, and as now this resistance is cut out when the headlamps are switched on. The modification to the switchbox is comparatively simple and can be carried out using the standard moulding and brush pieces, the only extra non-standard brush being the one with extra set in it carried from below. This is shown on print of D.Sch.554 attached. Since the above work was completed a new development has arisen in the form of a substantial improvement to the 20/25 dynamo. This is something we have been trying to get for a long time, and has the advantage of being immediately available. There is, however, a factor not yet mentioned which enters into the utilization of any increased dynamo output, and it is the danger of burning out side lamp bulbs due to the voltage building up in the S & T. position when the battery is full up. This occurs in some cases now on our 20/25 where the full charge is on in the S & T. position. We, therefore, anticipate it will be necessary to have some resistance in the field with improved output for S & T. only, but the cutting in point must not be debited too much. This amount of resistance is not enough for general Summer daylight running, and this accounts for the proposal to introduce a third rate of charge which is low enough to be left on all the time, and is just enough | ||