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).
Testing procedure for a Self Starter Dynamo and Motor to ascertain core losses.
| Identifier | ExFiles\Box 34\3\ Scan099 | |
| Date | 11th May 1915 | |
| R.R. 235 a (400 T) (S.C. 598. 16-2-16) C. 1546. C O P Y. To Na.{Mr Nadin} from R.{Sir Henry Royce} c. to J.{Mr Johnson W.M.} c. to Wor.{Arthur Wormald - General Works Manager} R4/IB11515. May 11th, 1915. Re Self Starter - Dynamo and Motor. With reference to ascertaining the core losses in the various armatures we have made for the self starter, to see whether the insulation between the plates is satisfactory, Mr. Ellis has so far produced no results which are of much value to us in this particular line, so will you please arrange with Mr. Wormald to supervise these experiments or get them transferred to Mr. Haldenby, who may have time to attend to them. I think the way to find out at three or four speeds, say (1) At 1500 revolutions. (2) At 2000 " (3) At 2500 " (4) At 3000 " The hyestersis losses can then be separated from the foricault losses by the usual process. It should be done with and without copper on the armature, that is, one should test the core before the winding is put on, but this may not be convenient in this particulat case. The machine under investigation should be driven by a motor of known efficiency. It could, in this case, be either direct coupled or driven by an effecient belt, such as the Whittle belt that Mr. Haldenby has been experimenting with. I think a belt drive would be most convenient to obtain the speeds, and a means of changing the size of the pulley. It would be necessary to find the extra watts required to drive it when the exciting current was put on. This would be the amount above the watts necessary to drive it without the exciting current. | ||