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 semi-earthed electrical system for Goshawk units.
| Identifier | WestWitteringFiles\K\October1923\ Scan93 | |
| Date | 29th October 1923 | |
| To R A E.{Mr Elliott - Chief Engineer} from EPC. c. CJ. c. EX. MP. ORIGINAL EFC1/T29.10.23. X.9860 - SEMI-EARTHED ELECTRICAL SYSTEM WITH GOSHAWK UNITS SUGGESTED FOR E.A.C. Herewith please find small photostat diagram which has been adapted from the original diagram of the standard Goshawk system to show a semi-earthed electrical system, mainly as described in EFC4/T24.10.23. (1) The wire colours and sizes have been left on, but these need not be noticed. (2) The dynamo diagram is the Goshawk (the E.A.C. goes the other way) but it does not affect matters to leave this unaltered. (3) What was the main positive emergency fuse has now become the negative earthing fuse and needs only to be of slightly greater capacity than the ordinary fuses. It might even be the same gauge, without much disadvantage, making all the fuses the same size and their holders the same. (4). The dynamo armature and field fuse though shown might be cut out, being as previously explained not now required. (5) If a fine field fuse is desired against the condition of the battery being removed, this one could be retained, but the fuse would not then be of uniform size with the others. (6) There would be no harm in retaining the dynamo and field fuses as they are at present, if desired. (7) A further alteration to the distribution box would be that the end of the series wire now earthed would have to be taken round to one terminal of the negative earthing fuse, as shown. (8) It would also be intended, though not shown on the diagram, that the negative pole of the instrument lamp plug socket should also be brought back to the same point, instead of being earthed. This actual scheme is not suggested seriously but merely as a basis for consideration. EPC. | ||