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 performance comparison of a re-wound Lucas E.575 dynamo armature against the standard winding.
| Identifier | ExFiles\Box 36\4\ scan 238 | |
| Date | 11th August 1921 | |
| X. 3014G- To Sft.{Mr Swift} from EFC. c. Wor.{Arthur Wormald - General Works Manager} EFC5/T11.8.21. X.3014b - LUCAS E.575 DYNAMOS. With reference to the dynamo recently handed over to us by Mr. Gemble, the armature of which he had re-wound, claiming to have reduced the amount of end connections and thereby to have increased the ampere output of the machine, we do not find this dynamo to be any material advantage over the standard winding. It is quite true that the dynamo as delivered to us had a larger ampere output than the average standard machine, but this might be due to other causes such as control brush position, contact with commutator, or air gap, etc. In any case, comparative measurement of the resistance of this armature against the standard armature shows the resistance to be very approximately the same and it is really on a comparison of the armature resistances, in the case of two armatures with the same scheme of winding, that the relative merit of the two armatures should be judged. Further to this we do not consider that really want more ampere output - the ampere output of the standard machine at moderate and high speeds exceeds considerably that called for in our specification. The respect in which the machine does not meet the specification is that little or no charging current is given in the early stages. Contd. | ||