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).
Technical explanation of current regulation in a dynamo-battery circuit, detailing the interaction of series and shunt coils.
| Identifier | WestWitteringFiles\K\June1923\ Scan54 | |
| Date | 2nd June 1923 | |
| Contd. -9- load current, which is the battery current, remains constant, though the two (dynamo and load) currents themselves increase progressively, and at the same rate. Actually we find the condition to be more nearly like the second one described. The really desirable condition would lie somewhere between the two. Even though a suitable intermediate condition were thus arrived at, it would seem a poor way of attaining it, viz, by the use of imperfect switch contacts. Since the above remarks refer to current regulations only, they are unaffected by the temperature condition of the machine. In normal conditions of the battery, as previously stated, the auxiliary relay will not operate. We have, however, by increasing the resistance to the battery circuit (keeping the back E.M.F. the same) allowed the voltage to rise so as to operate the relay. This having taken place, the load current, since it circulates in the opposite direction round the two coils of the regulator, is now unaffected as regards regulation, so that virtually the battery is dealt with by the dynamo with combined series and shunt coils, in much the same way as if the load current were non-existent, and the dynamo will give to the battery a supply having a volt-ampere characteristic determined by the proportion of shunt to series ampere turns and resistances. This was demonstrated to be the case. The main current through the main series coil alone which will open out the regulator contacts, is about 8 amperes. Contd. | ||