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).
Output characteristics of a dynamo, particularly when connected to a battery.
| Identifier | ExFiles\Box 62\3\ scan0120 | |
| Date | 21th January 1931 | |
| EFC. Works. X6076 PN.{Mr Northey}1/PH.21.1.31. X.6076 DYNAMO OUTPUT. X.3374 Referring to your EFC3/AD19.1.31., it will certainly be a very desirable achievement if you find that 20% increase of output will be available with the 56 coil armature after the size of the slots has been increased. The idea, also, of using a smooth cored armature for these small machines is interesting, although I fear the driving pegs would relatively take up a lot of room. You will remember that in your EFC5/AD.23.12.30. to me you did not agree with my contention in respect of the automatic rise of output of a dynamo when coupled to a battery, when running at constant speed, but, surely, the following paragraph of your memo first referred to - "The simultaneous rise or fall of voltage and amperage of a chassis dynamo arranged for output speed control by being connected to a battery, is not limited to those of the simple third brush type but is a universal characteristic of any type of machine, the armature reaction control of output of which with speed is dependent upon being connected to a battery. The phenomenon exists only, of course, when the speed is high enough for such control to take effect. At the speeds below the peak output the law is similar to that of a constant speed shunt wound machine in which the voltage falls as the load increases." is hardly consistent with the remark made in your previous memo as follows:- "It is the case that the output of such a generator does increase "merely as a result of being coupled to a number of cells across which the P.D. is capable of rising" even though the speed does not increase." PN.{Mr Northey} RECEIVED 31 JAN 1931 | ||