- DLldng kinh di~n cvc
§8.1 KHAI NIEM CHUNG VA PHAN LOA
1. N guyeD Ii lam vi~c ella liJ cam ting (hay 1b t~n 86) 18 d\ia veo hi~n hl<;lng cam
!lng di~n lu. Khi d~t m9t kh6i kim IO<;li vao trong mQt tu trtibng bi€n thi~n thl trong
kh6i kim iOl.li sEl xuat hi~n (cam !lng) cae dong di~n xoay (dong Foucault). Nhi~t
nang cua dong di~n xoay Be dot neing kh6i kim IOIili.
2. Nhiet nang truyen va~ kim IOl;li ph\! thuQc nhi(!u y~u tei : - Di~n tro sua:t f va M so tu tha:m .u cua kim lo~i
- Cuong d9 tit truong H,
W . = Hnhn~'t 2 =I2
Thvc M khOng the' tAng mlii dong di~n dd tAng cubng dQ ttl trubng vi dAy phAi rat
USn vA qua. nong, co thd nong chAy (du cd m.t(!c lam mat).
- TAn 86 dong cam ung
Wnhiet "" Vf
Th\ic M, thubng dung phudng pbap nay. Do v~y 1(') cAm dng con gQi IA 10 tAn s6 va ngu6n clp cho 10 11\ ngu6n di~n t!1n 86 caD.
3. NguOn dien caD tan cd th~ tlilo ra bhng nhi@U eAch
- Dilng mAy phAt di~n Un 86 cae : do hl;ln chl1 v~ kfch thu:tJc vA 86 vong quay n~n giAi t~n 56 ema eAc mAy phAt di~n quay khOng quA 10kHz. Hi~u 8uilt cua cAc mAy nay cd th~ dlilt ca 11 = 70 + 80%. Do mAy phAt nAy dllQC chl1 t~o vtJi t~n s6, cOng 8Utlt, di~n Ap nh4t dinh n_~n khi cAn gift nhi~t vtJi di~n Ap khAc th4p hern, thu:ang cAn cO bi~n Ap d~ ph6i hc;fP cAe them 86 giua ngu6n vii. phl,l tAi.
- Dung dl'ln phAt di~n ti't : khi c~n tqn 86 Mn hern 10kHz. Hi~u su4t cia dl'ln phAt di~n ti't chi dlilt khoang 11 ... 60% vi qua nhi@U khau biA'n d6i vA t6n hao nhi~t Mn.
- Dung thyristor .: con bi bJ;I.n chA' {) giAi t~n 86 cao vA. cOng su4t Mn. Sit dVng t6t a cAc 10 trung t~n cOng 8u4t nhO vA vU:a.