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).
Results of tests on a Smith dynamo and comparing different exciting circuits and fuse systems.
| Identifier | ExFiles\Box 61\2\ scan0405 | |
| Date | 5th October 1920 | |
| X2515 To EFC. from R.{Sir Henry Royce} Copy to CJ. " " EAC. " " Pn.{Mr Northey} " " R.R. of America Inc. (For the attention of CY). X.2951. X.3936. X.3014b. X.3560. X.2515. X.796. RE SMITH DYNAMO. I am pleased with the tests that you have carried out with the Smith dynamo and feel sure that this was burnt up in my case through the main fuse having blown and the field fuse remaining in, so that the machine was excited in this particular case, at the battery voltage, and your confirmation of the way in which it is roasted proved this to be the case. At a very early date I would like you to find out whether the Lucas scheme, and the more usualy single exciting circuit from the third brush is any better in this respect, that is, can the main fuse, if one is used, blow without roasting the dynamo ? I assume that there is nothing to choose in the matter, but I should like your assurance that the third brush dynamo is, or is not, superior in this respect, because it would influence our selection. It would be decidedly advantageous if we could find something which would permit fuses without risk of roasting, as the vibratory type of regulator will do. We are returning the parts of the Bosch dynamo. The tunnels formed by the armature plate we notice only permit Contd. | ||