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).
Outlining the requirements for two high-tension transformers for insulation testing.
| Identifier | ExFiles\Box 24\2\ Scan033 | |
| Date | 22th September 1920 | |
| To Wd.{Mr Wood/Mr Whitehead} from EFC. c. to Wd{Mr Wood/Mr Whitehead}/Ms. c. to By.{R.W. Bailey - Chief Engineer} X.1109 EFC8/T22.9.20. X.1109 - TRANSFORMER FOR INSULATION TESTING. X.1581 Mr. Royce is anxious that we develop the testing of insulating materials both experimentally and on production. For this purpose we shall require two high tension transformers, one for the Expl. Dept. and one for the Production Testing Dept. We should be glad if you would send out enquiries to suitable firms as to what transformers, designed for insulation testing, they have to offer. It should be stated that our available alternating current supply is at 200 volts and 42 frequency and that it would appear necessary to have a secondary voltage up to a maximum of 20,000. We consider that the regulation of the secondary voltage could be conveniently obtained by having a bank of lamps of variable resistance on the primary circuit with an A.C. voltmeter (and one lamp) connected across this primary circuit for measurement. A convenient ratio of secondary to primary turns would be exactly 100 to 1, so that the secondary voltage would be got for the voltmeter reading by multiplying by 100. Cap. about 1 K.V.A. EFC. | ||