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).
Dynamo output of 56 coil 20/25 dynamos with unmodified and modified poles.
Identifier | ExFiles\Box 62\3\ scan0134 | |
Date | 26th January 1931 | |
X5661 Ey. from EFC. c. Sft{Mr Swift}/Mr.Brock. EFC4/AD26.1.31. X.5661/3. DYNAMO OUTPUT OF 56 COIL 20/25 DYNAMOS WITH POLES UNMODIFIED AND MODIFIED. Further to our EFC2/AD20.1.31 we now attach blue print copy of curves 1. for the 20/25 which in the present connection are with particular reference to the modification of a number of 56 coil 20/25 dynamos on U.S.A. cars. In connection with sending instructions for the modification to U.S.A. we have requested you in our EFC2/AD20.1.31 to have the necessary instruction and drawing sent to U.S.A. We have taken the necessary curves which are exhibited as I and III on the attached blue print. I. Being the 14 volt curve for the present standard 56 coil machine III. The curve for this machine as recently pole piece modified by Mr.Brock. It will be noticed that the two curves are for the same temperature rise setting and incidentally also for the same control brush angle though the main brush angle has been altered 6° by the change, as the two curves can be compared on a strictly comparative basis and shew up in a suitable manner the later cutting in and better keeping up qualities of the modified machine. EFC. P.S. We have in the meanwhile received your Ey/RN{Mr Robinson}17/N26.1.31 and two blue prints to D.52129 detached. We will therefore ourselves undertake the sending of the necessary complete instructions to U.S.A. | ||