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).
Comparative test results and conclusions for an experimental dynamo versus a standard model, page 2.
| Identifier | ExFiles\Box 168a\3\ img167 | |
| Date | 14th March 1935 | |
| -2- Ha/Wat.50/M.A.14.3.35. Cont'd.{John DeLooze - Company Secretary} Sparking Test. at 13.0V, 14.0 amperes, 5250 R.P.M. Experimental. Standard. Positive - normal to bad sparking. Positive - very bad sparking some flashing. Negative - normal to bad sparking. Negative - very bad sparking, very bad flashing. Cutting-in speed 13.0V at 80°C. Experimental. Standard. 740 R.P.M. 790 R.P.M. High speed heating test. Experimental. Standard. 12.75 amperes at 13.0V, 5250RPM. 11.75 amps. at 13.0V, 5250RPM. Conclusions. It will be seen from these test results that a considerable improvement was observed in the performance of the dynamo. The improvements briefly are :- (1) Considerable reduction in sparking, and in particular, a reduction in sparking at the negative brush so that the degree of sparking is similar at both brushes. (2) An appreciable increase in low and high speed outputs. We consider that these improvements warrant the redesign of the brush gear on both the 20/25 and the 40/50 & Bentley dynamo as soon as possible. It may be possible to effect a still further improvement by the use of larger brushes and experiments in this direction are in hand. Ha/Wat. | ||