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 curves and specifications of a standard 20 HP dynamo.
Identifier | WestWitteringFiles\U\January1930-April1930\ Scan008 | |
Date | 1st January 1930 | |
EFC4/AD2.1.30 contd. -2- a good deal less than half the major output, it would be necessary to put the two brushes very near together in a twin holder. In this connection we attach to R's, PH's and E's copy of this memo a print of three curves for the standard 20 HP. dynamo, the two extreme curves of which represent the outputs at 80°C. of this dynamo at the extremes of control brush range allowed by the adjustment provided for production setting to our specification. It must however, be stated that the large output curve shown is considerably higher than the maximum permissible curve on the continuous heating basis, and could probably not be used in any circumstances except full automatic charge reducing control operated by dynamo temperature (see below). A chain dotted curve is shown which represents our estimate of the possible safe output curve of this standard 20 HP. dynamo in circumstances in which a manually operated charge reducing control switch interconnected with the head lamps is used. It will be understood that the curves given are for the present standard 20 HP. dynamo and not for the 20 HP./intermediate output type, curves of which were reported with our EFC2/ADL4.12.29. The possible curve in this other case would be about two amperes higher on the peak but with a later cut in. Reverting to the standard 20 HP. case the control brush span on the commutator is 10.9°, the total movement obtainable is 15° and the estimated movement corresponding to the change of output from the lowest curve to the chain | ||