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).
Production difficulties and testing of condenser capacities, leakage, and temperature variation.
| Identifier | WestWitteringFiles\K\October1923\ Scan102 | |
| Date | 29th October 1923 | |
| Contd. -8- EFC3/T29110.23. those for which the temperature is increasing. Then again it must be borne in mind that at the higher temperatures a fair proportion of the current is leakage, though this cannot, from calculation, be the case for some distance immediately above the L points. The difficulty on production at present appears mainly to be to get the condenser capacities within the limits given, which are :- from .275 m.f. to .325 m.f. at 18°C and from .41 to .52 m.f. at 45°C. It is curious that though the U.S.A. Bosch condenser is even worse than our own in this respect of variation, the Liberty condenser is considerably better. In this connection it will be remembered that we reported (see our EFC2/T5.9.21) that we found the Bosch condenser to heat up due to dielectric losses, allowing quite a large current, about 1/3 ampere, to flow before the supply was removed, without taking permanent harm. Also we reported in our EFC2/T27.9.21 that we had removed a Liberty condenser from one of the sets and finding it to be made in two halves had sent one of these halves to R.{Sir Henry Royce} for his examination. Further, that on the 400 A.C. R.M.S. volt test this condenser, unlike the Bosch, kept quite cool and did not develop any leakage conductance. Also that on the Delco Packard ignition condenser which is very similar to the Liberty we found a slight leakage of current. We must now again examine the remaining portion of the Liberty condenser. EFE. | ||