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, 'r :.-----.
I . I 1
.!n, 1:ll '11,
I
~X 0.06 _
li" = '000' 4-'/ 1()~7'= 47.7) A-Um_ x 11" .
f!e/,.= 47.75x 0.055'=2.63A-t
76 ELEOP.OMECHANICALENEI\GYCONVERSION
FIGURE2.8
'Aoç;:"'I~rl/::..ri..)x
Oen5Ir;~so:'\c
r:e!c.!nrensirfes
~or:J<omple 2,':
MAGNEnC.FIELDENEf\GYCONV~RSION 79
,<;>
: ';
t ~
For thecenterleglheairgapis
lBu 2 x 0.06 'Ho"='-- =4 ; 10-7 =,95.492.97Act/m/.Lu 1T x ' ,
H'kX =95.492.97x O.I)!=954.93 1\-(
.'The magncticpar!is
' ~ J
outerleg,2Buwill bethetlu.xe.!ensityin lhecen(érlegbecauseof lhesameuniform
areaoftheentirecircuit.Ontheotherhand.lheforce01'attractionexperienced,
by thecentralregionoi theironbar\ViIIbefour:il11esasmuchasexperienced
by theouterregions.Thus.from'Eq.(,2.34). '
Thus..them'mfneededfor thecel,lterleg is'
/Fe ""2.63'" 954.93'?'957.5óA-'
andtotalmrnfrequirementsare
<"::#'~i:'t).51)$6+4gL28::'é1438A~4A-l ..
, , Thus,lhecurrentinthe:doc(isor 'O.S47X 41Tx 10-' =0.06 T. ,/Bo'=\J ' ,.. .n_~
Duc to ~ymmelry.!he:nmfrequirementsoi eachaf :heouter,Iegswill bethe
same.In lheoUlerair,gap. '
1438.84 ='14.39A1=1õQ
Fromlhemagneticcircuitanalysis.
0.06
7Hu = ,1\ -=4746.-18A-tlm, 4õT:< - ,
HI).~'" 47.746.,18x 0.01= 47i.-I6A-l , NI?>.=- and
Õ" <b
L '" N~ _ N<b
;11.- T
In theoUle~magneticrcgion.
. From Eq. 12.25).
~...and
0.06
2000:~4'" x 10~-
HI/I =23.X7': tI.16=;.82 A-(
.. I ,1 1
W, =:;LI- =:;N!<b=:;NIBA
23.S7A-tim
wheredi is lhetluxlinkipglhe~oil.Therefore.il is lhe t1uxin thecenter,kg.
" Substilutinglh:: values01'Ouxe.!ensilY,me.!lhecross-sçc,lionaJarca01'theccnter
leI!inthe precedingcxpre'ssion.weobtain "
Thus.lhemmfneedcdforone01'lhe:outer'legsis
IV, -=lU x 100x 14.39x l~ '>(O.C)6);( I :< :no" = S.6mJ