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).
Methods for improving and testing coils, with reflections on past failures due to moisture absorption.
| Identifier | ExFiles\Box 164\5\ img018 | |
| Date | 5th January 1931 | |
| R1/M5.1.31 contd. -3- by putting it on an alternating current circuit - i.e. test it to destruction and then make it still better insulated. And, also provide on the coil some limit to the voltage such as a 10 mm. spark gap with reliable points to limit the voltage to say 8,000 or 10,000. After learning all we can from Ferranti and the American coil, or any other source, I shall look out for a further report from EFC. One might expect that something could be done by impregnating firstly by a vacuum then a pressure of say 100 lbs. per sq. in. Also the coil case might be arranged to be filled with insulating oil as is used on transformers for power lines. My experience with Remy coils was that American coils failed in England because they absorbed damp and were made in a dry climate for a dry climate. The same as 30/40 years ago we suffered in England by moisture getting into our dynamo and electro motor work. At WW we generally have trouble with magneto fibre absorbing moisture and the contact makers failing. The troubles were never so bad on the European continent and in U.S.A. R.{Sir Henry Royce} | ||