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).
Page 2 of a letter discussing experiments and issues with battery ignition systems and dynamo armatures.
| Identifier | ExFiles\Box 37\1\ scan 154 | |
| Date | 1st July 1927 guessed | |
| 43 -2- Contd. Such was not the case in our old type of steering column switch, the position of which was not readily noticed to be wrong. It occurs to us that another a reason for the non-continuance of the manufacture of battery ignitions in this country may be the difficulty of running the battery ignition points satisfactorily, though I have no evidence that this is really the case. I should like to know your impression in the matter. We do not think, - I might well say we know - that the problem of the battery ignition contact breaker points is a good deal more difficult than that of the magneto ignition contact breaker points, on account of the fact that reversals of current do not take place. We have proved by automatically reversing the current on a battery ignition system on the bench about four times per minute, that we can run the battery ignition points extremely satisfactorily, i.e. in the absence of oil and petrol vapour. We are, however, making a long series of experiments with a view to improving the operation of battery ignition platinum (and tungsten) points with uni-directional current, and we feel that we are well on the way to arriving at the point at which the U.S.A. manufacturers apparently have already arrived in regard to the satisfactory running of these contact points. We are getting to know something about the necessary conditions for the completely correct running of these points which I may say are not by any means mainly electrical. We can run on our own electrical system on a contact breaker of U.S.A. manufacture with tungsten points with results which we are now approximating to on our own contact breaker. My object in writing to you is to have your impression of the matter, moreparticularly as a technical expert than as a representative of Messrs. Lucas, and in this connection I trust you will treat certain of the above remarks referring to our own position in the matter as confidential. You will be interested to know that we have put in hand an experiment on a dynamo armature with slots closed with steel wedges, as suggested by yourself. We have used for this purpose an armature with straight slots which we made as an experiment and found to be a very bad howler. We shall be interested to let you know the result of this in due course. Have you further considered the possibility of using a number of slots which is a multiple of four (4-pole machine)? So far as we have gone we are apparently meeting with good success in this direction. Yours sincerely, | ||