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).
Use of ballast resistance in place of a fuse in a constant current dynamo circuit.
| Identifier | ExFiles\Box 61\2\ scan0291 | |
| Date | 26th January 1920 | |
| X.2515 To Ck.{Mr Clark} from R.{Sir Henry Royce} Copy to CJ. " " Bn.{W.O. Bentley / Mr Barrington} " " Oy. R2/G26.1.20. X.294. - RE CONSTANT CURRENT GENERATORS. X.2515. X.3716. I am sorry you went to the trouble of putting the ballast resistance in place of a fuse in the field circuit of a constant current dynamo. This could not possibly have any good effect unless it were of the same nature as a fuse, and depended upon its protection properties by change of resistance from practically nothing to a very high amount, i.e. some material that will change its resistance with temperatures enormously. I know of nothing sufficiently effective. | ||