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).
Effect of brush position variation on the output of the Smith Dynamo.
| Identifier | WestWitteringFiles\D\May1920\ Scan68 | |
| Date | 19th February 1920 | |
| R.R. 235A (100 T) (S.G. 643. 19-2-20) G 2618 To R.{Sir Henry Royce} from EFC. c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to Bn.{W.O. Bentley / Mr Barrington} c. to Da{Bernard Day - Chassis Design} c. to PN.{Mr Northey} ORIGINAL EFC2/T1915.20. X.295 - SMITH DYNAMO. We attach photostat copy of some curves showing the effect of variation of brush position on out-put for the Smith type A dynamo, that is, the first dynamo received. The type 2D dynamos now being received do not differ from this in principle but have a rather earlier cutting in speed. The object of the curves is to show what can be done in the way of altering the out-put of the dynamo by shifting the whole brush system forward or backward, the expression forward implying a motion in the direction of rotation and vice versa. It will be noted that the cutting in speed is not affected. In obtaining the curves the machine was first of all allowed to run under normal conditions until fully hot; then the middle curve was taken, after which the lower curve and top curve were taken in order. It is probable that if the machine were allowed to continue running for any time with the out-put according to the top curve, overheating would result. It might, however, be useful in some instances to know that the out-put can be varied in this way. Similar curves will be obtained in due course for the Lucas E.575 dynamo. We have already made use of the principle of moving the control brush on the Lucas A.400 | ||