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).
Policy proposal for standardizing dynamos and regulators, including implementation details for Wraith and Bentley models.
| Identifier | ExFiles\Box 168a\4\ img064 | |
| Date | 9th March 1938 | |
| - 2 - EY.5/G.9.3.38. (e). For future policy we propose to standardise a dynamo with a modified armature, having 36 commutator bars and two turns less per coil in the winding. This dynamo to be used in conjunction with a new regulator having 2 1/2 series turns instead of 3 in the regulator itself. The effect of this will be to give an output of 19 amps, plus or minus 2 under full load conditions. The modification to the dynamo would enable us to run the machine in question at regular car speeds of 70 to 75 miles per hour with full lamp load on without running the risk of burning out the armature. Sufficient work has been done with the new armature and regulator to justify a standardisation sheet being issued at once, so that we can bring in the improved armature and regulator at 101 in 'D' or sooner if possible, the deciding factor being the point to which we have actually built armatures, as we cannot, of course, afford to scrap complete machines, but we must not hesitate to scrap material. With regard to the fact that we are introducing at 101 in 'D' a new regulator, and that we have ordered to the end of 'D' the present type of regulator, we propose to accept this 100 and hold them against the incidental replacements necessary on the 600 or 700 cars in service. These regulators can and will be re-set by the makers to the higher setting before delivery, and as such will be good stock as pointed out above. (2). WRAITH AND BENTLEY. Wraith will go into production with the present armature, which was standard on Bentley and 25/30, but will be used in conjunction with the 'higher setting' regulator, that is the one having three series turns for current control, but it is essential in my opinion that we should introduce at the earliest possible moment the experimental armature now on test having a larger number of commutator bars and less turns per coil, similar to P.III, in conjunction with which we would use the regulator having 2 1/2 series turns for current control, thus ensuring a higher output with sparking prevented, to a much higher engine speed. This modification is, in my opinion, as important on Wraith and Bentley as the improved dynamo is for Phantom III. | ||