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).
Guide on how to cure noise from Lucas dynamos by adjusting the control brush.
Identifier | ExFiles\Box 36\4\ scan 166 | |
Date | 20th August 1920 | |
X30146 20th August, 1920 No. 105 X.30146 X 4211 RE. NOISY LUCAS DYNAMOS One of the chief complaints we have had against the above dynamo is that of noise. The noise referred to is that which is most pronounced when the dynamo is generating and at its cutting-in speed. We now find that this can generally be cured by shifting the control brush. In doing so, however, it may be found that the output of the dynamo is reduced slightly and at the same time it has the advantage of cutting in at a little lower speed. When curing the noise, should the dynamo suffer from this weakness, the following should be the procedure:- 1) Slack off the 3 fixing screws on the control brush carrier ( a bent screw-driver may be necessary for the bottom screw). 2) Start up engine and get the speed of dynamo, where the sing is most pronounced with charging switch in (as explained above), then with strip of wood move the control brush a little advance, or retard until the sing disappears. 3) The movement should not be more than 1 of the commutator segments from its original position. Great care should be taken in this operation as one may move it so as to completely short the dynamo. One may also trap the main leads so as to cut nearly through their insulation, and may develop a short after running some time on the road. In so altering the position of the control brush, you tend to lower the amperes you now get at high speeds, i.e. 12, but an earlier cutting-in speed is obtained, which we think is an advantage for town driving, and medium speeds, but this cutting-in or balancing speed depends so much on the condition of battery. 4) Carefully lock up fixing screws, and in replacing dynamo end cover, do not trap the brush pigtails, which may easily lead to trouble. | ||