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).
Preliminary report on the Bosch regulated dynamo, comparing its performance to the existing third brush controlled type.
| Identifier | WestWitteringFiles\W\September1931-November1931\ Scan096 | |
| Date | 21th November 1931 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Pgt. c. Sg.{Arthur F. Sidgreaves - MD} c. Wor.{Arthur Wormald - General Works Manager} R.{Sir Henry Royce} c. Da.{Bernard Day - Chassis Design} EV.{Ivan Evernden - coachwork} PRELIMINARY REPORT ON BOSCH REGULATED DYNAMO. This dynamo is a shunt wound machine suitable for our 40/50 chassis, and the output of which is prevented from rising above a certain value, with increase in speed, by means of a vibrator regulator. From a performance point of view, the regulated shunt-wound type of dynamo is undoubtedly better than the third brush controlled type, like our own. The reasons for this are : (1) With a regulated dynamo the highest output is obtained when it is most required i.e. when the battery is down, or when there is a big lamp load on. With our type of machine we get the highest output when the battery is fully charged, and there is no load on the battery. (2) The output does not fall off at high speeds as it does with our type of machine, but remains more or less constant at all speeds. (3) The output rises much more sharply with the regulated machine so that full output is obtained at low speeds. The points on which we are doubtful of the regulated type of dynamo lie entirely in the regulator itself. They are : (a) The mechanism of the regulator is not of such a robust nature as the mechanism of our two-rate charge control and must therefore be of good design and well made, to be as reliable. (b) What life the regulator contact points will have in view of the fact that a certain amount of sparking must take place at these points. | ||