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).
The polarity of magneto and battery ignition systems and the potential for static induction.
| Identifier | ExFiles\Box 61b\4\ scan0206 | |
| Date | 25th February 1925 | |
| Contd. -4- EFC1/T25.2.25. possible to run both ignition generators at the same time (which has not been done in the tests described), and while so doing, this spark gap would be observed for any sparks of length appreciably larger than we have so far observed. The arrangement by which we drive the two generators gives no exact relation between the speeds and it is considered to be just as likely, as in the case of the chassis system itself, for the electrical synchronisation of a magneto and battery impulse of the same polarity to occur at rare intervals. We say of the "same polarity" because whereas all the battery sparks are of the same polarity, the magneto sparks are of alternate polarities, and the effect described would not be additive unless the magneto and battery ignition impulses occurring at the same instant were of the same polarity. If we were using two battery ignition systems, it might possibly be an advantage in this respect to run the two ignitions with opposite spark polarities (this could be done by reversing the primary coil connections) as a means of obviating this static induction. EFC. | ||