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).
Conference at the Air Ministry discussing the feasibility of battery ignition on aero engines.
| Identifier | ExFiles\Box 179\2\ img249 | |
| Date | 8th March 1932 | |
| R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Wst. c. Cg. Wor.{Arthur Wormald - General Works Manager} c. RK. R.{Sir Henry Royce} c. DK. ORIGINAL Hs{Lord Ernest Hives - Chair}/Wst.3/A.M.8.3.32. X6131 X6102 BATTERY IGNITION ON AERO ENGINES Rg.{Mr Rowledge} and myself visited the Air Ministry on Tuesday 9th inst. in order to attend a conference convened by Major Bulman for the purpose of discussing the question of battery ignition for aero engines. In addition to ourselves there were present representatives from the Bristol, Armstrong Siddeley, and Napier Cos. On the Air Ministry, in addition to Major Bulman, there was present Mr. Bairsto of the R.A.E. and Mr. Antage. All present unanimously agreed that a battery ignition set would prove satisfactory from an engine ignition point of view up to the highest speeds which are now attained by modern aero engines. Mr. Bairsto outlined the R.A.E's views of the whole matter which were as follows :- (a) Radio Interference. This he considered would be an almost insuperable obstacle for the following reasons. First, linking the ignition coil primary to the battery from which all the aircraft lighting circuit radiate, would mean impressing upon the whole electrical system the peak E.M.F. primary disturbances occurring every time the contact points break. These induced voltage peaks on the coil primary may even reach a value of 1000 volts and as the voltage waves are unidirectional and very highly damped, they are difficult to filter in the usual way by means of chokes and condensers and they can also by "shock excitation" cause disturbance over a wide band of radio wave lengths. He stated that these disturbances could only be screened by either screening the whole of the general electrical circuits which would mean increased weights etc., or by introducing a system of chokes and filters in the general electrical service side of the battery. Secondly, he considered the magneto to be a self contained unit whereas battery ignition introduced extra wiring away from the engine. We consider this to be a very weak argument. | ||