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 Ltd. concerning battery ignition system contact points and the 'make' vs 'break' period.
| Identifier | ExFiles\Box 37\1\ scan 157 | |
| Date | 6th July 1927 | |
| X3199 EFC1/T. 6th July, 1927. Dr. E.O. Turner, Messrs. Joseph Lucas Ltd., Great King Street, Birmingham. Dear Dr. Turner, We thank you for yours of the 1st. inst. ref. EOT/6. We were interested to know if satisfactory results generally were being obtained with battery ignition contact points on battery ignition systems of British manufacture. Presumably you yourselves will be using tungsten, as you have now gone to this on the magnetos. The satisfactory running of contact points on battery ignition systems appears to be a bigger problem owing to the use of uni-directional current. We are not quite clear as to the meaning of the last clause of your third sentence in your last but one para. where you say "the object, of course, being to obtain a longer period of make than is practicable with a single contact breaker lever". Is "make" in that sentence an error for "break" ? We can see there might be an object in having a longer period of break to give the points more time to cool down. In fact, we ourselves are making an experiment in that direction of running a cam with only half the number of lobes (with same period of make) for twice the time, it having been suggested that if this shews any improvement, two contact breaker levers operating alternately might be used. We thank you for your remarks concerning the dynamo. Yours sincerely, | ||