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).
Suggested modifications for the R.R. distribution board.
| Identifier | ExFiles\Box 61\2\ scan0324 | |
| Date | 17th February 1920 | |
| X.2515. 17.2.20. X.3555. - R.R. DISTRIBUTION BOARD - SUGGESTED X.2515. MODIFICATIONS. (1). That the insulating plate on which the bars are mounted be made to cover a greater portion of the aluminium surface, the object being to lessen the possibility of short circuits. Also that the small earthing terminal for the shunt coil of the cutout be covered up with an insulating thimble. (2) That two fuses be provided, firstly, a field fuse through which the current for the field windings of the dynamo and to the shunt coil of the cutout in parallel has to pass. Secondly, a main circuit fuse between the series winding of the cutout and the main four points switch, through which the main current has to pass. We have proved experimentally on the bench that such a system of two fuses will give the best protection that can be expected, as follows:- A.{Mr Adams} If the dynamo be run without the battery connected and with the switch on, the field fuse will go, after which the field circuit of the dynamo and the shunt circuit of the cutout will be dead and the only thing that will happen will be that the dynamo will remain partially excited in the control winding. The control current is, however, under these circumstances less than normal and will therefore do no harm. A slight amount of sparking on the control brushes occurs under these circumstances at high Contd. | ||