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).
On the practice of replacing ammeters with control warning lamps on chassis electrical systems by Continental manufacturers.
| Identifier | ExFiles\Box 168\5\ img221 | |
| Date | 1st November 1931 | |
| X6132 To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Wst. c. E.{Mr Elliott - Chief Engineer} c. SG.{Arthur F. Sidgreaves - MD} Hs{Lord Ernest Hives - Chair}/Wst. 2/AMO.11.31. AMMETERS ON CHASSIS. Y6132 Both the Bosch and Scintilla concerns, which are the two largest Continental manufacturers of electrical equipment, have discarded the ammeter as a means of indicating charge and discharge on chassis electrical systems. Instead of the ammeter a control lamp is used mounted on the switchbox. This lamp is arranged to light when the engine stops if the ignition has been left on and to switch off when the dynamo is charging. The lamp alight when the engine is running will indicate therefore that the dynamo is not charging. This warning light is also a common fixture on several English cars supplied with Lucas equipment, but the ammeter is still used. Hs{Lord Ernest Hives - Chair}/Wst. | ||