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).
Magneto performance, comparing different models and suggesting design improvements.
| Identifier | WestWitteringFiles\O\2January1926-March1926\ Scan27 | |
| Date | 27th January 1926 | |
| Expl. Report. -2- EFC4/T27.1.26. absorbed in reducing this current to zero before any is available for building up the current in the desired direction. We are asking Wd.{Mr Wood/Mr Whitehead} to take up this point with the Watford Magneto Co. as it appears to us to be wrong in principle. We are further suggesting that long cams might be made in such a way as to give a quick break, but a slow make, on the principle that the relatively quick break is necessary to preserve the timing of the break consequent upon a variation of the platinum point gap, whereas the timing of the make can be varied without serious effect over a wide range in the neighbourhood of the zero of the open circuit volt curve of the magneto. Also, if noisiness is due to hammering of the points at make, this might improve matters. This Lucas magneto and the two Simms magnetos have tested out very satisfactorily on our bench tests. Making a 2° allowance for the difference of the range provided, and our requirement, we can say that in electrical performance all the three machines meet our specification in every respect, particularly on (a) Utility tests and (b) The speed range for satisfactorily sparking a standard leaky test gap, and on high speed sparking the results from these magnetos are somewhat better than those of our standard. On the low speed sparking characteristics they are, in the advanced position, considerably better, though in the retarded, Contd. | ||