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).
Modifying series windings to improve electrical output performance for headlamps and different driving conditions.
| Identifier | WestWitteringFiles\W\September1931-November1931\ Scan004 | |
| Date | 2nd September 1931 | |
| Hs{Lord Ernest Hives - Chair}/Pstl/AD2.9.31 contd. -2- By increasing the number of turns of the series winding we can probably raise the output above that shown in curve 3. although there appears to be a limit to this in that we may appreciably affect the brilliancy of the head lamps if much resistance is introduced in this winding. On the other hand, every increase in the size of the series winding means a reduction in main winding space. From what we have done we think that, as regards night running with head lamps on, the output performance with the series winding could be made at least equal to what we are at present getting in respect of cutting in and peak output, and possibly better on the peak by raising it to 14 amperes. The shape of the curve would, however, be much the same as at present. For day running the output would be the same as at present with the difference that it could not be altered as it can at present by merely altering the value of the resistance unit. We consider this last point is important as we feel that an output that is sufficient for conditions of long distance day running, is not sufficient for conditions of slow speed town work, and that greater flexibility in day running output than even a two-rate charge scheme permits, is necessary to bridge the difference in driving conditions. To do this it would be necessary to give the customer two day time charging rates to use at will. Our next step would normally be to try the series winding increased by one or two turns per pole, but we should be glad to have your criticisms and definite instructions on the matter. We also attach a print of curves which show similar tests carried out on a machine fitted with the present standard armature. Hs{Lord Ernest Hives - Chair}/Pgt. | ||