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 increased static induction effects on H.T. wires from synchronized battery and magneto ignition sparks.
| Identifier | ExFiles\Box 61b\4\ scan0213 | |
| Date | 26th February 1925 | |
| EFC. WA.{Mr Wallis}112. 26.2.25. INVESTIGATION OF THE POSSIBILITIES OF INCREASED STATIC INDUCTION EFFECT ON H.T. WIRES, DUE TO OCCASIONAL SYNCHRONISM OF THE BATTERY AND MAGNETO IGNITION SPARKS. The present standard black fibre tube was used in conducting this experiment, which consisted of observing the effect induced on a spare (13th) wire threading the whole length of the tube and connected to earth at one end, viz. a variable spark gap. A.{Mr Adams} (1) Firstly with the magneto wires sparking and the battery wires switched off, the maximum length of gap was obtained, which for an observed period of 5 minutes, would avoid the passage to earth of induced sparks from the terminal of the spare (13th) wire. This was found to be .119". (2) With the battery ignition wires sparking and the magneto switched off this gap, for the same conditions, was .114". (3) Both ignitions were then switched on together and the induced sparking observed on the gap (this being set to the previous max. value, i.e. .119") It was observed that sparks would jump this gap approx. once every 20 secs; the maximum gap to avoid, during 5 mins. a spark over, being increased to .129". B. The last test was carried out with battery ignition polarity normal, and so secondly the effect was observed with the polarity of the coil reversed. The max. gap now necessary to avoid induced sparks jumping (battery ignition wires sparking only) was observed to be .184". On switching both ignitions on together (B.I. polarity still reversed) sparks were observed to jump approx. every min., the initial spark over being followed Contd. | ||