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).
The technical development of an automatic charge control switch, referencing previous experiments.
| Identifier | ExFiles\Box 59\1\ Scan333 | |
| Date | 9th September 1928 | |
| X4008 EFC/T9.9.28. X.4008 TECHNICAL DEVELOPMENT OF THE AUTO CHARGE CONTROL SWITCH. The Midgley combined cutout and control unit was examined, experimented upon, and reported in our EFC3/T24.6.26. We happened to have by us an otherwise standard R.R. cutout which had been fitted with a back contact (i.e. a contact which would break when the armature was drawn home, instead of make) and it occurred to us to look into the question of arranging this as an electromagnetic switch unit for inserting a resistance in the dynamo field circuit. In our EFC1/T8.10.26 we referred to the possibility, advantages and disadvantages, of utilising such an automatic switch on the R.R. car, basing our arguments on our conception, as it was at the time, of only reducing the charge to about half normal, as was done in the Midgley case, and on the assumption that the two operating coils would be the pure shunt field coil and a de-magnetising coil in series with the supply to the headlamps. The operation of such apparatus was described. Later, in our EFC1/T4.12.26, we reported upon the actual operation of such a unit on the bench, at the same time pointing out that the objection to the use of such an apparatus was that it was the subject of a patent taken out by Mr. A.H. Midgley. There was in the tests a suggestion of vibrator regulator action, but was, as stated in the report, considered that this would be of no consequence under working conditions. Contd. | ||