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).
Alternatives to achieve the desired field winding resistance for a PH.III Dynamo.
| Identifier | ExFiles\Box 168a\3\ img490 | |
| Date | 20th April 1938 | |
| 6142 To Rm{William Robotham - Chief Engineer}/RC.{R. Childs} BY/RD.3/B.20.4.38. RESISTANCE OF FIELD WINDING - PH.III DYNAMO. In order to obtain a field resistance of 6.5 ohms, we have had field coils made up with fine covered wire. With the thinnest covering we can obtain in either D.C.C. or Enamelled S.C.C. it is not possible to accomodate sufficient turns in the space available. The alternatives are :- (1) To provide some external field resistance. (2) To use a smaller gauge of wire (20 SWG). We propose to instruct a field winding of 20 SWG. wire, unless you can tell us that this has already been tried. BY/RD. | ||