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 the effects of running on five cells, the charging switch, and the utility of a voltmeter.
| Identifier | ExFiles\Box 54\1\ Scan110 | |
| Date | 11th August 1926 | |
| X4617P EFC2/T. 11th August, 1926. Mr. G.R.N. Minchin, Messrs. Peto & Radford, 50, Grosvenor Gardens, London, S.W.1. Dear Mr. Minchin, Y8280 Thank you for your letter observing the effects of running on five cells. You do not say if you can notice any appreciable beneficial effect on the cutout contact points, or on the ignition contact points, and whether the functioning of the cutout as indicated on the ammeter was reasonably O.K. As you suggest, Mr. Royce has now arranged that the first position of the charging switch shall be battery and magneto, but that there will be an additional switch for earthing the magneto for testing the battery ignition. In regard to the volt-meter, Mr. Hives has asked me to write something on the utility of this instrument on the system and I will let you have a copy of this when it is done. In the meanwhile it would appear desirable to fit the voltmeter between the dynamo positive terminal and chassis frame, because then the voltmeter would be automatically 'off' as long as the charging switch were 'off' and would not need an additional push button. If the voltmeter were put across (1) Dynamo terminals, (2) Battery (3) Head lamp terminals, there would be disadvantages in each case which do not occur in the suggested arrangement. It would not do to only have the voltmeter when the head lamps were 'on' because one of the principal reasons for the volt-meter is to indicate the high voltage on/charge. full Contd. | ||