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).
Trends in automotive electrical equipment observed at the Olympia Motor Show, covering ignition systems, dynamos, and horns.
| Identifier | Morton\M9\ img059 | |
| Date | 30th October 1931 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Wst. ORIGINAL. c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to Hy.{Tom Haldenby - Plant Engineer} Hs{Lord Ernest Hives - Chair}/Wst.1/KT.30.10.31. X3374 ELECTRICAL EQUIPMENT AT OLYMPIA. Ignition. The Lorraine engine had its battery ignition distributor totally enclosed with a large rubber cap, the wires all emerging from the top. All coil makers now, including Bosch, have gone over to the outside primary type of coil. It is a well known fact that there is a difference in the electrical performance of an ignition coil when hot as compared with cold, and one car, the 12 cyl. Cadillac, had the coil let into the thermostatically controlled radiator thus keeping the coil temperature constant. A number of high class cars now fit dual battery ignition a notable example being the new 12 cyl. Hispano which has its four Scintilla coils mounted in a cool place on the dash behind the instrument board. A warning light to indicate when the ignition has been left switched on, is the rule rather than the exception. Bosch substitute this light for an ammeter as the cut-out is arranged to switch off this warning light thus indicating whether the dynamo is charging or not. With dual battery ignition this warning light will be important as a discharged battery would mean a derelict car. Dynamo. The Scintilla and Bosch automatically controlled regulator dynamos are fitted to the large continental cars. American cars still favour the Delco-Remy thermostatically controlled third brush dynamo presumably on the score of cheapness and simplicity. Horns. A new idea with H.F. horns in order to obtain a loud penetrating note is to fit two small H.F. horns tuned so that one is a semitone or so higher than the other. When both horns are sounded together the two notes beat in together or heterodyne producing one very powerful note. The racing Bentleys were so fitted and the Lucas people say that for high speed cars there is nothing to beat this. Instruments, etc. The majority of cars had grouped instrument | ||