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 discussing a compromise on the thickness of ebonite separators and their effect on resistance and charging.
| Identifier | ExFiles\Box 54\1\ Scan091 | |
| Date | 22th February 1926 | |
| x4617P EFC3/T. 22nd February, 1926. Mr. G.R.N.Minchin, 50, Grosvenor Gardens, London, S.W.1. x4655 Dear Mr. Minchin, Thank you for your letter of the 13th inst., informing me that you are back. I hope you have had a satisfactory time. During your absence I have had some correspondence with Mr. Preston with reference to the thickness of the ebonite separators. He has been keen on reverting to the .4 mm. ebonite largely from the point of view of reducing the internal resistance on discharge, whereas I had the impression at the time that it was largely from the point of view of reducing the P.D. on charge. Owing to the high voltage phenomena which we have experienced lately, I rather readily acceded to a reversion to the .4 mm. ebonite, and in my last letter to Mr. Preston I asked him to justify the change if possible on the score of the charging P.D. Now there is a suggestion that a compromise should be made which, amongst other things, will bring us into line with the Exide, the compromise being the use of .5 mm. ebonite as against .4 mm. on the one hand and .6 mm. on the other, and I think that if you can arrange this, this would be a move which will satisfy every body. From what Mr. Preston says it does not appear that this will materially affect the charging P.D. as compared with the use of .4 mm., and as regards resistance on high rate discharge we have not noticed any difficulty with this resistance so far, and I think the slight difference it would make would be negligible. Contd. | ||