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).
Report comparing the capacity, volume, and performance of various ignition condensers.
| Identifier | WestWitteringFiles\G\September1921\ Scan88 | |
| Date | 27th September 1921 | |
| R.R. 235A (100 T) (S.H. 798. 10-12-20) C 2947 Contd. -2- EFC2/T27.9.21. is .15 mf. this being half the total. The useful volume is estimated to be .56 cu.in. so that the capacity per cu.inch is .27 mf. i.e. rather higher than we get on our mica condensers. The portion we are sending to Mr. Royce has been subjected to the same routine tests as our mic-a condensers on production, satisfactorily, the test including 10 minutes on 400 A.C. R.M.S. volts, during which test the condenser kept quite cool and did not develop any leakage conductance. It will be remembered that we reported in our EFC2/T16.6.21 on the Delco Packard ignition condenser which was very similar to the present, having approximately the same capacity, that we found a slight leakage conductance. X4275 The U.S.A. Bosch battery ignition condenser already reported in our EFC2/T5.9.21 which had a capacity of .5 mf. seems to have a remarkably high capacity per cu.in. We have not got one of these condensers out of its box, but we estimate the effective volume to be 1 cu.in. so that the capacity per unit volume is .5 mf. or equal to our ideal value for the mica condenser. It is very doubtful if we should be able to obtain ourselves anything like this space efficiency without considerable experience in making paper condensers. X3485 With regard to the condenser for the Goshawk battery ignition, we estimate the allowed useful volume of this to be 1.27 cu.ins. If, therefore, we estimate the same space efficiency as we obtain on the 40/50 chassis condenser. Contd. | ||