Vf dylO: Ap dl,lllg phuong phap d6ng d.i¢n nhAnh. tInh d6ng di~ trong clic nMnh cua m~h di~ hbih 1.38. LM giil :. Bubc 1: M~ch d.i¢n c6 2 nut A vA B, 56 mit n = 2; m~ch c6 3 oMnh 1, 2. 3, 56 nhAnh m = 3. 470 A • e ES 5V Hlnh 1.38. ~h di¢n diJng phuong phap dOng di¢n nhll.nh BllUC 2: ViS chi~u d6ng di¢n cae nhlinh II' 1 2 , 13 nhu hlnh 1.38. BllUC J: S6 mit eM vitI phuong trlnh KieeshOp 1 IA n -1 =. 2 - 1 =. 1. GlI;m mit A. PhU't1ng lrlnh KieeshC p 1 vitI eho ndt AlA: 1 1 -1 2 +1]=0 (1) Buuc 4: ChQn (m - n +1) = 3 - 2 + 1 = 2 ml,lch v6ng. ChQn 2 m{leh v6ng dOc l~p a, b nhu hlnh ve. Vilt phuong lrlnh KieC5hOp 2 cho m~ch v6ng a vA b. Phuang ~lnh KiecsbOp 2 cho m~ch v6ng a. 4711 + 22 12 = 10 Ml,lch voog b 2212 + 6813= 5 Bubc 5: Oiai h¢ 3 phuong lrinh ta c6 d6ng di¢n cdc nhAnh 11=138mA 1 2 = 160mA 13= 22 mA (2) (3) Phuong pMop dong di¢n nluinh giai trVC tie'p dugc cac dong di¢n cac nhlinh, song s6 phuong trlnh bAng s6 nhlinh m, wong d6i 16'0, doi hoi nhi~u thl1i gian Hnh toan giai M phuong trinh. Vi the'dum dAy dua ra cac phuong phd.p sir d\lng clic An s6 trung gian III dong di~n m~ch vong, di¢n the' mH, do d6 s6 phuong trlnh sf!! dugc giam b6t, nha vj).y tie't.ki¢m thOi gian tfnh toano 2. PhlJang phlip dimg di~D m,ch vbog o phuong pbap n~y. an ,6 trong M phuong "lnh khOng pMi a dong di~n cae nMnh, rna Itt mQt dong di¢n m(lch vong mang y nghla v~ toan hQc, vi ne'u bie't duqc chung, co tM d(!; dtmg tfnh dong di¢n cac nhanh. 19 cac buck giai thee phuong phap dbng di¢n mE.Lch yong nhu sau : Bwc 1: Xlic djnh (m-n+l) mE.Lch vbng d~c I~p yA tuy Y vi! chi~u dong di¢n m~ch yong. thOng thuang nen ch<;ln chi~u cd.c dbng di¢n m{lch ybng gi6ng nhau, thu~n ti¢n cho I~p h¢ phuong trinh. Bwc 2 : Vi!!'t phuong trinh KiecshOp 2 che mOi m{lch ybng thee cac dbng di¢n m{lch ybng d! Ch9n. Bwc 3 : GiAi M phuong rrinh vira thi!!'t l~p, ta c6 dbng di¢n m~ch vbng. BtWc 4 : Tioh dbng di¢n cae nhiinh thee dbng di¢n m{lch vbng nhu sau: dbng di¢n m6i nhanh bAng !dng d{li s6 dong di¢n m{lch yong ch{lY qua nMnh Ay. Vi dl,lll : Ap dyng phl.l'Ollg phBp dbng di¢n m~ch vbng giru m~ch di¢n hlnh 1.39. Lbi giai : BElue 1 : Sd m{lch vbng dQc l~p : I, 470 m-n+ 1=3-2+ 1 =2 m~ch vbng. Ve chi~u dbng di~n mij;ch vlmg I., Ib nhu hlnh v~. Hin" 1.39. MilCh di¢n ap dl,lng phm:mg phap dbng di¢n m;,teh vong 20 Bltoe 2 : Vi!!t phuong trlnh Kiecshop 2 cho cac m~ch yang. M,!-ch vbng a (47 + 22) I. - 22 Ib = 10 691 22Ib = 10 M,!-ch vbng b - 221. -+ (22+ 82)l b = -5 = ·5 BItCle 3 : Giii h¢ phuong trlnh dii thi!!t I$p 1 691 •• 221. = 10 -221.+104Ib =-5 SU dl,mg phuong phBp ma tr4n 10 -22 I := -S 104 '" (lO).(I04)-(-S).(-22) =O,i39A a 69 22 (69).104 (-22).( 22) -22 104 69 10 (I) (2) Ib =fc ,,2.2C ,5O;t= (69).(-S)-(-22).(l0) _-D,OUI7A 22 (69).104-(-22).( 22) 22 104 BUde 4 : nnh dllng di¢n nhanh II == I. == 139 rnA 12 == I. -Ib == 139 - (-18,7) == 158rnA Il == Ib == -18,7 ~A Dllng di¢n Il < O. do d6 IJ c6 chi~u ngU'Q'c l~i v{ji chi~u da ve. 3. Phuong pblip dl~D Ibl Dul Pbucmg phlip nay sir dq.ng an s6 tnlng gian III di¢n tht! cac mlt de thit!t I:).p h¢ phuong trinh. Bit!t di¢n tht! cac m1t, ta d! dang tinh dllng di¢n cac nh8.nh. Xet m~ch di¢n hlnh 1.40. A I3 3300 • I, ·3 ·2 ., =c Hl"h 1.40. M$Ch dien de tloh di~n ,bl! nllt Tuy '9 chQn truoc di¢n thl mOt diem coi la" bilt tcuoc. Thuemg IA'y di¢n tht! diem !y bAng khOng. o day chQn di¢n tht! diem C bang khOng : 'Pc = O. Dl!a vao dinh lu:}t 6m ta c6 d6ng di¢n cac nMnh II = EI -~A 14 = '1'8 RI R 4 . 12 = '£&. R2 I !jlA -'1'8 3- R3 Djnh Iu:}t Kiecsh6p 1 ~i nlit A I, - 11 - 13 == 0 21 El -<PA lPA _ lPA -<Po 0 Rl R2 R3 ( _1 +_1 +_1 )~A _(_1 )~B =(_1 ).E l Rl R2 R3 R3 Rl Dinh lu$t Kiecsh6p 1 ~i diem B I3-I4-I~=O <PA -<PB lPs _ Es +CPB =0 R3 R4 R, ( __ 1 ).q>A +(_1 +_1 +_1 ).q>B =_(_1 ).E, R3 R3 R4 Rs Rs Goi: GA =(_1_+_1_+_1_) - TOng dAn cUB cJ.c nMnh n6i vm nut A. . Rl R2 R3 On =(_1_+_1_+_1_) _ T6ng dAn cua c4c nMnb n6i vai nut B. R3 R4 Rs GAD = ( ~ 3) - TOng dAn chung giua 2 DIll A va B. 1 01 ". - - Di~n dAn nMnh 1. Rl 1 G, = - - Di~n dAn nhlinh 5. R, H¢ phuong trlnh di¢n the'mll se la GAlPA -GABlPB =G,El -GABCPA +GBCPB =-GsE S Giai h¢ phuong tclnh ta s! c6 di¢n the' c.6c nlll, va til' d6 tinh dugc dbng di¢n c4c nMoh. cae buac de gitU m,ch di¢n theo phuong pblip di¢n the' mlt la: Bltae 1: XBc dinh 86 mll n. BuO'c 2: OlQD mQt mlt bA"t ky c6 di¢n the' bie't tru6'c. Bltae 3: Tfnli t60g din cua c.6c nluinh n6i VOl mOi n6t GA. Go vh t6ng dAn chung cua c.6c nMnh giii'a 2 nlll GAD ." va di¢n dAn c~c oMnh c6 ngu6n G" Os. 22 B.roc 4 : L~p h~ phrnmg trlnh di¢n the' mlt. Buae 5 : Giiii b¢ phuong trinh ta co dil}n the' cua mOi nut. BltOc 6 : Sir d1}ng dinb lu~t Om Hoh dong di¢n c4c nMoh. Vi d~ 12 : Giii m{lch di¢n b hlnh 1.40 GA =(_1 +_I_+_I_)~(~+_I_+_I_)=O,OO66J , RJ R2 R3 470 680 330 0D =(_1 + _1_ + _1_) ~ (_1_ +_1_+_1_) '" 0,01403 RJ R4 RS 330 1000 100 GAB ~ (_I ) ~ _1_ = 0 0030) RJ 300 • I I Gl=-~ Rl 470 I I G5=-~ RS 100 H¢ phuang trlnh c1i¢n tM 0111 ' o,OO6630A -0,003030B~- '70 -7 -o.OO300<PA + O,014039B:- 100 Gilii h¢ phttang trlnh ta c6: CPA o,928V 'PB = -5,19V TIt d6 r.inh. duqc dong di¢n c'c nh4nh II = E,-f(lA _ 4,.5+0,928 -O,01l55A Rl 470 IpA -0,928 12 = !.Q.=-=-Q OOl36A RZ 680 ' I '" 'PA -CPR '" -0.928+5,19 =0 0l29JA 3 R2 330 ' ".!ll. -5,19 = -0 OO.519A R4 1000 ' IS = E:5 +<PP _ 7-5,19 =O,0l81A RS 100 23 Phoong pnap di~n the" nut dllQ'c sir d I}ng khi m~ch di¢n c6 nhil!u nhlinh it n( D~c bi~t khi m<:,-ch chi c6 2 nut (hinh 1.41), ta d! dAng tinh di¢n the' clla nut. CbQn <P!:.I : O. v~y chi cOn di¢n tM nut A IA a:n s6. GA<PA = OJ E J + G 3 E3 1, • A , , , 47 I, GA :·-+-+-=007892 472282' E, t lOV "" " 0, 0(_' )01- RI 47 • 0 3 :(:3)=8 1 2 Hinh 1.41. M{lCh di~n c6 2 nut G,E] + G3E3 = 0,27374 V~y phuong trlnh di~n tM nut A Ill. 0,078921j)A = 0,27374 OW ra ta c6: <PA = 3.468 V DOng di¢n cae nhlinh I "" B'-<PA:: 10-3,468 o.139A I RI 47 '2 = 2A."'~:0 158A R2 22 ' 5-3.468 -00187A 82 • cAu H6r ON TJ,.P vA BAr TJ,.P 1.1. Nguon cJj~n la gl ? Till Ie gl ? HAy eho c~c vi dl,l v~ nguon di$n ve tai. 1.2. Ph.it bi&u cJjnh lu~t Om. 1.3. Phat bi~u djnh 'Iu~t Ki6esMp. 1.4. Cae bllOe giai m~eh df$n bl!ing phl/ljng phap dOng cJi$n nMnh. 1.5. Cae bllOc gilll m~ch di$n bling phU'c1ng philp di$n th~ cae cJi&m nut. 1.6. Cho E '" 100V ; R = 10n ; f '" 5A. Tfnh dl~n ap u trong 2 SCI do hinh 81.6a va 81.6b. 24 E R E R - B A B A • • U M U" aJ bJ Hlnh 81.6 f)ap slf : a) VAG = 150V b) U BA = 50V 1.7. Cho E = SOV'; R = SO; U =- 40V. Tfnh dong d'i~n I trong 2 sd <16 hinh BUa v~ BUb. E U f)ap slf ; R • aJ 0)1= 18A bJ 1= 2A. E • U bJ HlnhB1.7 1.B. M~t tlli c6 dh~n tro R = 190 dA'u v~o ngu6n di~n m~t chi~u c6 E = 100V, tfI~n I"'; lrong R" = 10. Tlnh dong <l1~n I, <l1~n ap U v~ cOng su~1 P caa b\i. f)ap slf: I = 5A ; U = 95V ; P = 475W . 1.9. Cho mQt ngut'Sn di~n mt)t chieu c6 sac di.n d(mg E = SOV ; di~n Ira trong RIr = 0,1.0. Ngu6n di~n cung c§p di~n cho lai c6 di.n tra R. Bi~t cOng suA't tiSn hao trong nguon di~n U:l10W. Tfnh dong dI.n I, di~n lip U gilta 2 cl,I'C eua ngu6n di$n, di~n trO R vtl cOng su§t P tai tiAu th f)ap slf: I = 10 A; U = 49V; R = 4,9n; P = 490W. 1.10. ~Qt ngu6n di.n c6 sac di~n dQng E vtl dI~n tre, trong RII = 0,50, cung cA'p di~n cho tai c6 di~n tra R. Bi~t di~n lip cua tai U = 95V ; cOng suA't lal liAu IhV P = 950W. Tinh E, R. f)ap slf; E = tOOV; R = 9,5n. 25 1.11. B6n di';n Irtf R 1 , R 2 • R 3 • R4 m~c n6'i liA'p d.!iu vilo nguon di';n ap U 12V (d1';n Ira trong bling khOng). DOng di~n trong m~ch I = 25mA. di~n a tren cae di(ln tro R 1 , R 2 • R31tt 2,5V; 3V; 4.5V. Ve so d6 each da"u dAy, each m~c ampe kA', vOn ke de do ct:lc d~i IlIc;Jn IrAn. Tfnh d1(ln ap U 4 IrAn di';n Ira R 4 . Tfnh di';n Ira Rlo R 2 • R 3 • Rt . . D(1p s6: U. = 2V; R f = 100n R2 = 120n 1.12. 8i4ft 56 chi cua mtit 56 ampe kA' trAn hlnh R1.12. Xac djnh s6 chi cua ampe ka' Al vtl A, fJap slf : 1M = 3,5A IA2 = 2,5A R3 = 180n; R~ = 80n l , { • R, • I," Hlnh 81.12 R, R, 1.13. £>4 c6 c:Jl';n Irtf (luang duong) 150 O. ngl.l'Oi la da"u song song hai di';n Irtf Rl = 330 0 vtl R 2 . Tfnh R2 fJap slf: R, = 275n. 1.14. Hai di';n Ira Rl = 1000 vtt R2 = 470 da"u song song, biel dOng di~n a m~ch chfn'h I = 100mA. Tfnh dOng c:n';n qua ct:lc di~n Ira R 1 • R 2 • D(1p s6 : 11 = 32mA " 12 = 68mA 1.1 S. Dung phap bi6n ddi tllOng duong, tfnh dOng di~n Irong cac nMnh IrAn so d6 hlnh 81.15.Tlnh cOng suA't ngu6n vtl cOng suA'1 IrAn cac di~n tr~.Cho U = SOV ; R= 1,25n; R, = 6n; R, = Ion. fJflp slf : If = 1DA 12 = 6A I = 1-6A; P = U/ = 1280W; P R = 320W; 26 R I, I, R, R, Hlnh 81.15 P Rf = 600W P R2 = 360 W Ta thdy P = P R + P R1 + P R2 1.16. Tfnh dbng di~n I v~ cOng suA"t ngu6n trong Sd' a6 hinh B1.16. Cho U = 120V ; R 1 = R2 = R3 = 20 ; R4 = Rs = Rs = 60. f)lip .6: 1= eOA ;P= 7,2kW 1.17. Cho m~ch di$n trAn Hlnh 81.16 ", sd' d6 hlnh 81.17. Hay giai m~ch di~n trAn bAng 2 phU'd'ng phap sau : a) PhU'd'ng phap dbng di~n nhanh. b) PhU'd'ng philip cJI(m th~ cae nut (chQn di6m nut 8 c6 di~n th' bAng khOng). Cho El = 200V; Rl = 20; E2 = 170V ; R2 = 100; R3 = 20.0. " ", A ", " t t E, ", B Hlnh 81.17 eap sd: Ch9n chi~u dong difn nh<1nh nhu hlnh 81.17. a) " = 10A ; I, = 9A ; 12 = -1A (chi~u d()"g c.1ifn 12 (nhanh 2) nglf9G veji chi8u IIA vA). b) L~p phllOng Ir/nh lIi~n 1M nUt A, glili r. ~A = IBOV ; TV lIa ca U AS = 11' - II's'" 180 - 0 = 180V. Ap df,lng djnh lu~f Om cho cac nhanh fa c(): I, = 10A ; 12 = -1A " 13'= gA. 27 . (69).(-S )-( -2 2).(l0) _-D,OUI7A 22 (69).10 4-( -2 2).( 22) 22 104 BUde 4 : nnh dllng di¢n nhanh II == I. == 139 rnA 12 == I. -Ib == 139 - (-1 8,7) == 158rnA Il == Ib == -1 8,7. c1i¢n tM 0111 ' o,OO6 630 A -0 ,0 030 30B ~- '70 -7 -o.OO300<PA + O,014 039 B :- 100 Gilii h¢ phttang trlnh ta c6: CPA o,928V 'PB = -5 ,19V TIt d6 r.inh. duqc dong. II = E,-f(lA _ 4,.5+0,928 -O,01l55A Rl 470 IpA -0 ,928 12 = !.Q. =-= -Q OOl36A RZ 680 ' I '" 'PA -CPR '" -0 .928+5,19 =0 0l29JA 3 R2 33 0 '