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).
Responding to a query on the performance and heating characteristics of a vibrator regulated dynamo on model 58-GN.
| Identifier | ExFiles\Box 62\3\ scan0310 | |
| Date | 12th December 1932 | |
| X6142 PN.{Mr Northey} From Hs{Lord Ernest Hives - Chair}/Wst. c. to Sg.{Arthur F. Sidgreaves - MD} Hs{Lord Ernest Hives - Chair}/Wst.13/MA.12.12.32. Re. VIBRATOR REGULATED DYNAMO ON 58-GN. Replying to your PN.{Mr Northey}2/WT.9.12.32., regarding the above you will probably find that on switching on the head lamps the out put of the dynamo is not quite balanced by the head lamp load, but as the battery begins to discharge due to the debit the dynamo charge automatically increases, so that it is practically impossible for the battery to become totally discharged with head lamp loads etc. The dynamo for this car gave 13 amperes at 13 volts, this is raised to about 16 amperes at 12 volts. With regard to your second query the heating conditions on the dynamo are now totally different to the 3rd. brush dynamo. i.e. at high battery voltages the dynamo output is at its minimum, whereas at low voltages the dynamo is charging at its maximum so that the heating risk of the dynamo is governed by its output at 13 volts. We are testing these machines therefore for/rise by running them at their maximum rated output at 13 volts. /temperature The reason we take 13 volts as our figure at the dynamo terminals is because a certain amount of volt drop must be allowed between the dynamo and the battery at these high charge rates. Since fitting the dynamo to 58-GN. we have made a further improvement in general performance and heating with this 40/50 size machine, and we are also going into the question of whether it might be possible to so alter the characteristics of the regulator with the higher output obtained from this dynamo, so that the series winding does not cause the regulator to operate too early. Hs{Lord Ernest Hives - Chair}/Wst. | ||