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 performance curves of a non-trembler battery ignition standard coil, comparing different polarities.
| Identifier | WestWitteringFiles\D\May1920\ Scan21 | |
| Date | 8th May 1920 | |
| R.R. 225A (100 T) (S.G. 643, 19-2-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2618 To R.{Sir Henry Royce} from EFC. c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to EP.{G. Eric Platford - Chief Quality Engineer} c. to Bn.{W.O. Bentley / Mr Barrington} c. to Da.{Bernard Day - Chassis Design} c. to Hs.{Lord Ernest Hives - Chair} EFC1/T8.5.20. X.3129 - BATTERY IGNITION. STANDARD COIL. X 3445. We attach maximum gap - speed curves of the R.R. non-trembler battery ignition, using a recent production coil, for comparison with those sent to you under cover of our EFC2/T13.4.20. The two curves given are for the two different polarities. Curve A is for the polarity which hitherto has been the better sparking polarity on the bench but the worse on the car. It will be remembered that we had found a considerable difference in the earlier coils between the two polarities, the better sparking polarity on the bench occurring when the high tension terminal was negative, and the better on the car when the discharge at the insulated points of the sparking plugs was positive. There was much better regularity of sparking on the bench in the former direction, but those sparks which did occur over the same gap on the bench in the latter direction could possibly be a little longer and were always more noisy. There is very little difference now between the two polarities on the bench. Further, it will be noticed that the curve is very much flatter than before. Contd. | ||