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).
Proposal for an additional resonance test on Dubilier made condensers to detect weaknesses.
| Identifier | ExFiles\Box 34\1\ Scan229 | |
| Date | 21th March 1921 | |
| Contd. -2- EFC7/T21.3.21. the condenser terminals, and this test would only be of 10minutes duration. This test imposes a voltage about the same as that attained in the 18 volt battery test, but of a more sustained nature and therefore probably equally likely to produce a weakness in the condenser. A test of this kind will not necessarily break a condenser down owing to the fact that the moment a weakness is caused, this disturbs the resonance and the voltage is lowered. We think, however, that if there is a weakness in a condenser, this can be aggravated by the resonance test in such a way that the ordinary standard production test carried out afterwards would enable the condenser to be broken down. If not, then we should say there was no initial weakness. We therefore propose as the required additional test for these Dubilier made condensers 10 minutes of this resonance. In the ordinary way a transformer is not required for this test as 600 volts is obtained by the resonance direct on the 200 volts from the main supply, by applying the mains to a circuit consisting of the secondary winding of a Remy 6 volt 6 cylinder coil in series with the condenser on test, and a small moving iron instrument of the pocket voltmeter type used as a milli-ammeter for this purpose. When in strict resonance the number of milli-amperes obtained is that calculated by Ohm's law from the... Contd. | ||