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).
Letter to Joseph Lucas Research Laboratories regarding issues with the damping on their ammeter.
| Identifier | ExFiles\Box 168\5\ img300 | |
| Date | 7th August 1934 | |
| e.Roup/M.S. Y 6172 Expl. Dept. HS{Lord Ernest Hives - Chair}/Wst.5/WJ. 7th. August, 1934. The Joseph Lucas Research Laboratories, Great King Street, Birmingham.19. For the attention of Mr. L.C.Toulmin. Dear Sir, Replying to your letter of the 1st. inst., reference X/1679., we are not entirely satisfied with the method of damping in the Lucas ammeter. Under the action of a low frequency current oscillation as is normally experienced with a voltage regulator the needle is certainly much steadier than with the Standard Lucas Ammeter. The instrument needle however swings right over the scale when a heavy current discharge of 10 amperes is switched on due to the inertia of the damping mass, and in some instances the needle stuck over on the stop. We consider this to be an undesirable feature on ".a." cars. In the interim we have fitted to our cars with voltage regulators the Weston moving iron instrument which has a very efficient air damper. We are quite willing to continue testing Lucas ammeters but before going any further we should like to eliminate the objectionable feature outlined above. Yours faithfully, For Rolls-Royce Ltd. | ||