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 a revised wiring scheme for the ignition indicator lamp.
| Identifier | ExFiles\Box 61b\4\ scan0189 | |
| Date | 2nd February 1931 | |
| To Sg.{Arthur F. Sidgreaves - MD} from EFC. c. E.{Mr Elliott - Chief Engineer} c. Ry. Wor.{Arthur Wormald - General Works Manager} X 6114 EFC6/ADL 2.2.31. X. 6109. JAPAN 3. ELECTRICAL SYSTEM. X 6114. Referring to El/M6.2.31 but with particular reference to item (4) "red lamp now to be used to indicate when ignition switch is left on", we assume that E.{Mr Elliott - Chief Engineer} has not in mind that the red lamp indicator be connected in parallel with the ignition circuit so as to remain on all the time the ignition switch is on, but that the idea is that it shall be connected in such a manner as to indicate by showing a light (1) That when the car is stationary the ignition switch is on. and (2) That when the car is running current is being generated by the dynamo. It is possible to achieve this by arranging a "back" contact on the cutout - then one end of the lamp circuit is connected to No.3 terminal on the distribution box feeding the ignition circuit and the other end to the back contact on the cutout. It will thus be seen that when the ignition switch is put on the lamp lights, the current passing to earth via the cutout frame and cutout series coil and that when the dynamo runs up to speed so as to operate the cutout the red lamp is put out by the back contact of the cutout being broken. This scheme would appear to have the additional advantage that the red lamp will come on when the car is running if dynamo output fails for any reason, either by accident or design. We therefore commend this arrangement for consideration. EFC. | ||