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).
Calculation for the separation of hysteresis and eddy current losses in different machines.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan226 | |
| Date | 26th May 1936 | |
| 26.5.36. SEPARATION OF HYSTERESIS AND EDDY CURRENT LOSSES Let 1000 R.P.M. be the unit of speed so that a speed of S means S x 1000 R.P.M. Then on the assumption that the combined hysteresis and eddy current loss is W = AS + BS{A J. Barnes - Assistant Manager}2 where A represents the hysteresis loss constant and B the eddy current loss constant (which assumption transpires to be reasonably true) we find for the standard machine tested the approved average values - A = 34.6 B = 18.3 and for the N.B. machine A = 20.8 B = 11.4 Similarly for the N.B. machine with finer armature plates A = 20.4 B = 7.6 Thus Standard W = 34.6 S + 18.3 S2 N.B. W = 20.8 S + 11.4 S2 N.B. with finer armature plates. W = 20.4 S + 7.6 S2 EFC. | ||