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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. {E. Fowler Clarke - Electrical Engineer}
  
  
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).


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