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).
Investigation into dynamo failure and output variations on the Phantom II model.
| Identifier | ExFiles\Box 62\3\ scan0104 | |
| Date | 15th January 1931 | |
| X7660. Ha/GWH.{George W. Hancock - Head Chateauroux}1/KT.15.1.31. X.6066 Re PHANTOM II. DYNAMO FAILURE. X.7660 We have observed during the run of Phantom II cars the maximum dynamo output has varied. This variation has come about when the car has been travelling over rough roads, the output being greater and less by 2 amperes. We have also had the dynamo output decreased by as much as 3 amps. after an engine has back-fired. This trouble seems to be apparent on customer's cars, as during my investigation work at Cricklewood there were several instances brought to my notice of the irregularities of the dynamo output after being fitted. We have found these variations in the output are caused by the movement of the control brush in its holder. The trouble is amplified when the control brush becomes tight at the top of the holder and remains free at the bottom. This causes it to rock forward and backwards making the contact of bedding of the brush on one side and then the other. This alters the output of the dynamo considerably. It is always noticeable when the control brush is taken out for examination there are two distinct bedding shown. Ha/C.W.Hancock. | ||