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).
Test report on the performance of tungsten contacts when run on a lower voltage.
| Identifier | ExFiles\Box 35\6\ scan 078 | |
| Date | 6th October 1921 | |
| 2-1. Wright 1-9-21 G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2000 COPY. EFC. AB.26. 6th Oct. 1921. X.2894 - TUNGSTEN CONTACTS RUN ON A LOWER VOLTAGE. For the above test, a set of points previously used on test cars were faced up and fitted to the distributor. 8 volts were used in the primary circuit with a small resistance, as the normal running current could not quite be obtained on 6 volts. The set ran fairly well for 118 hours when it was seen that they were not performing any better than on a standard 12 volt circuit. On removal, the characteristic discolouration and transfer of metal were found. Firing was fairly regular during the run and there was no appreciable resistance at the contacts. The running current was 1.0 amps. The test does not indicate that operating at a lower voltage will have any beneficial effect on tungsten points. Sgd. F.J.A. | ||