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).
Technical report on testing paper and mica condensers, and tungsten contacts for ignition systems.
| Identifier | ExFiles\Box 35\6\ scan 076 | |
| Date | 10th November 1921 | |
| Contd. -2- EFC1/T10.11.21. In the latter half of the report, there is some indication that a paper condenser of similar capacity may be an improvement over a mica condenser, owing to the suggested increased damping effect due to the presence of more di-electric hysteresis. The idea is that this may more effectively damp, not the primary oscillatory current between the primary and the condenser, so much as the tendency for the later and much higher frequency oscillation in the local circuit of the condenser and the primary spark at break. Increased circuit resistance would not increase this particular damping. As mentioned in the last paragraph it is suggested trying a mica condenser on an American ignition set, or alternatively it would suggest a run on our standard ignition with a paper condenser of similar capacity to the standard mica condenser. This will be instructive to try. The tungsten contacts fitted to blades and screws by the Tungsten Manufacturing Co. which we reported as fitted to 1 EX and running with the Bosch condenser are still in very good condition, though they have only run for a period at first with the Bosch condenser. They are still running on 1 EX with the standard condenser and are reported to be giving results which are considered as good as any tungsten contact results which we have had on the car. In fact results which can be said are almost equal to those of platinum, as although the points have pitted a little bit, nevertheless they are not being burnt away to the same extent as platinum might be. EFC. | ||