T IN- Hai t in gi l mc song song nu chng c chung im u v chung im cui- Hai t in g l ni tip nu im u ca t ny l im cui ca t kia.tuy nhin, ty vo tng mch in, bn phi tp t duy mch, v li mch, dn dn s nhn ra ci no song song hay ni tip vi ci no thi.T iNthc ai cng bit T th thng c dng lc cc xung nhn trong in Ac . Vy ai c th cho mnh bit r hn l v sao dng t th n lc c cc xung . Nguyn tc lc ca t nh th no ?t lc ngi ta dng l t c cc tnh hay cn gi l t ha.t ny c 1 bn cc m v 1 bn cc dng.khi in p cc dng ca t dng hn in p bn cc m th t bt u np.v khi in p cc + nh hn cc - t s x in nu c ni t trong 1 vng kn.nhng xung thay i bin s ng vi qua trnh np x ca t.Do in khng ca t in l mt gi tr ph thuc tn s. Khi tn s cngn cao th in khng ca t cng nh. Li dng tnh cht ngi ta dng t in lc ngun. Vi in p khng i (f=0) th in khng ca t l v cng ln do vy ko h g. Vi in p AC th in khng ca t gim i, nh vy n c tc dng nh mt thit b chn lc tn s cc tn s cao th cho i qua nhiu (i xung GND) cn tn s nh th gi liT in vi dng 1 chiu v xoay chiu* T in khng cho dng in 1 chiu i qua tVi in p mt chiu th t hon ton cch in v p mt chiu c tn s F = 0 Hz m Dung khng ca t li ph thuc vo tn s theo cng thc Zc = 1/ ( 2 x 3,14 x F x C ) khi tn s F = 0 Hz th dung khng Zc = v cng, do t khng dn in mt chiu .* T in c cho in p xoay chiu i qua khng, v i qua nh th no ?*in p xoay chiu li i qua c t lThc ra khng c in t (e ) no i qua hai bn t c, t dn in xoay chiu l v tnh cht phng np ca t in. khi in p bn ngoi ln hn in p gia hai bn cc th t np in v ngc lai khi in p bn ngoi nh hn th t phng in , in p xoay chiu lin tc i chiu do t cng lin tc phng np v tr thnh dn inhttp://bka.vn/forum/threads/tu-dien.873/T in c s dng rt nhiu trong k thut in v in t, trong cc thit b in t, t in l mt linh kin khng th thiu c, mi mch in t u c mt cng dng nht nh nh truyn dn tn hiu , lc nhiu, lc in ngun, to dao ng ..vv...- Cho in p xoay chiu i qua v ngn in p mt chiu li, do t c s dng truyn tn hiu gia cc tng khuych i c chnh lch v in p mt chiu.- Loc in p xoay chiu sau khi c chnh lu ( loi b pha m ) thnh in p mt chiu bng phng . l nguyn l ca cc t lc ngun .Vi in AC ( xoay chiu ) th t dn in cn vi in DC( mt chiu ) th t li tr thnh t lct giy v t gm (tr s nh) thng lp trong cc mch cao tn cn t ho (tr s ln) thng lp trong cc mch m tn hoc lc ngun in c tn s thpDi y l mt s nhng hnh nh minh ho v ng dng ca t in.T ho trong mch lc ngun.Trong mch lc ngun nh hnh trn , t ho c tc dng lc cho in p mt chiu sau khi chnh lu c bng phng cung cp cho ti tiu th, ta thy nu khng c t th p DC sau i t l in p nhp nh, khi c t in p ny c lc tng i phng, t in cng ln th in p DC ny cng phng.* T in trong mch dao ng a hi to xung vung.Mch dao ng a hi s dng 2 TransistorBn c th lp mch trn vi cc thng s cho trn s .Hai n bo sng s dng n Led du song song vi cc CE ca hai Transistor, ch u ng chiu m dng.Ngoi ra t n cn c ng dng nhiu trong thc t.

http://bka.vn/forum/threads/tu-dien.873/

TUDIENT giy, T gm, T mica. (T khng phn cc )Cc loi t ny khng phn bit m dng v thng c in dung nh t 0,47 F tr xung, cc t ny thng c s dng trong cc mch in c tn s cao hoc mch lc nhiu.T th thng c dng lc cc xung nhn trong in AcLc nhiuT ho ( T c phn cc )t c phn cc m dng , t ho c tr s ln hn v gi tr t 0,47F n khong 4.700 F , t ho thng c s dng trong cc mch c tn s thp(lc nhiu) hoc dng lc ngun, t ho lun lun c hnh tr..t dn in xoay chiu l v tnh cht phng np ca t in.nu mch knDo in khng ca t in l mt gi tr ph thuc tn s. Khi tn s cng cao th in khng Zc(m) ca t cng nh =>d cng d i qua. Li dng tnh cht ngi ta dng t in lc ngun. Vi in p khng i (f=0) th in khng ca t l v cng ln do vy ko h g. Vi in p AC th in khng ca t gim i, nh vy n c tc dng nh mt thit b chn lc tn s cc tn s cao th cho i qua nhiu (i xung GND) cn tn s nh th gi liT in cho in p xoay chiu i qua v in p xoay chiu c tn s > 0 do dung khng ca t < v cng, khi t dn in nh mt in tr (nhng t khng tiu th cng xut nh in tr ). tn s in xoay chiu cng cao hoc in dung t cng ln th Zc (dung khng) cng nh v in p i qua t cng d dng.Chn ga tr t lc C=1/(Mm.W.R.Kmra)Mm=2 do mch chnh lu cu 4 diottn strng thitr t Ctr khngKm=0,1F=0khng quanh nhtZc ln nhtW=2pi.f=2pi.50=100piF=1qualn hnZc nh hnt lc c tn s f=1/(2.pi.X.C)F=2qua nhiu hnln hn naZc n hn naF cng cao hoc C cng ln: cng d quaI) Mch chnh lu bn k :F=0F11). in p trung bnh khi khng c t lc(in p m ta c c t VOM):Khng quaQuaVav=0.45Vm(Vm in p ngun hay in p th cp ca bin p)C0 nh nhtC1 ln hn2) in p trung bnh khi c t lc:Vav= 1.414Vm104=100000 PF=0.1 ufara =100 nF3) Thng s chn Diode chnh lu:Dng trung bnh qua Diode:Q=2*pi*f*U^2*C=0.314*U^2*C ,KVARU: in p t ln cc ca t in, KVC: in dung ca t in , mFId=Iav=Vav/RLCng thc tnh dung lng t l : C =10^6/2*pi*f*XTrong X : in khng ca t(ohm)p ngc cc i t trn Diode:Vd=VmII) Mch chnh lu ton k:1) Vav khi khng c t lc:Vav=0.9VmXc = 1/C = 1/2fC2) Vav khi c t lc:Vav=1.414Vm3) Thng s chn Diode chnh lu:Dng trung bnh qua Diode:Id=Iav/2=Vav/(2RL)p ngc t trn Diode :Vd=2Vmkhi ta lm b ngun chuyn i t 12vAC ->12vDC 5A, th cch la chn t in nh th no ? ( vd : sau ci cu diot 5A th l con t 2200uF tng ng vi ngun 12v. 10000uF tng ng vi ngun 35 - 40v ) c cng thc no m ta c th xc nh c gi tr con t ny khng ? c phi l 1mv tng ng vi bao nhiu uF ?

Chn t lc :C=I.T/(Vpp) (F)C:L Gi tr ca t (F)I: L dng in (A)T :L chu k T=1/f ; f:tn s (Hz), vi in p ang s dng th f=50HzVpp: L nhp nh nh-nh, thng ta chn n bng (1).III) Chn t lc:C=I.T/(Vpp)(F)C: Gi tr ca t (F)I: dng in (A)T :chu kT=1/f; f:tn s (Hz), vi in p trong nh th f=50HzVpp: nhp nh nh-nh, thng ta chn n bng 1 thi

CUN DYdng in 1 chiu sau chnh lu c gn m cun cm c kh nng chng li s tng hoc gim ca dng in nn lm cho n bng phng hnDng in sau cu chnh lu (dng diode) gm 2 thnh phn:1/ phn DC2/ phn gn sng cn st li ca thnh phn AC.i vi thnh phn DC, cun dy (cun cm) ch l thun tr c gi tr khng ng k, do thnh phn DC qua cun dy d dng.- i vi thnh phn gn sng (AC) cun dy c cm khng (XL= 2pi*F*L) m to ra mttr khng (tnh bng Ohm) ngn chn thnh phn gn sng sng ny. Kt qu l sau cun dy ta c thnh phn DC phng!t sau 78 (trc ti) l kh nhiu do ti gy ra, v d mch ca bn c Servo , khi ng - ngt servo th cun dy trong ng c phng/np in lm in p ca ti "nhp nh", cun L c tc dng nh vy.Cn "khi no dng" v thng s th phi tnh ton c th mi ra kt lun c.Nu nhp nh vy th dng t lc c th c chc nng lc ca cun dy khng ?Nu kh nhp nh c tn s thp th c. i khi bc cng thy t lc b song song vi t nh y bc, nhng va c t va c cun dy th hiu qu lc cao hnMnh vn cha hiu tc dng lc ca t & cun cm khc nhau th no. t th mnh cn bit lc tn s thp c t hng chc uF, trm uF hay ngn uF, lc gn tn s cao th c t hng pF, nF. Vy th cun dy lc lc tt im no.?- Choke (e ch ni n choke lc ngun, khng ni n choke ti): li dng tr khng ln khi c mt dng in xoay chiu "cn" cc thnh phn nhiu, nhp nh trn phn ngun DC- OPT: li dng hiu ng Cm ng in t bin i tn hiu xoay chiu p cao/dng thp sang tn hiu p thp/dng cao ph hp vi ti; ngoi ra cn c chc nng cch ly ngun cao p vi ti.Nh e ni trn, cc OPT c trch nhim bin i tn hiu xoay chiu, ch khng phi lc/ngn cn nh choke ngun v do hon ton khng c chc nng lc ngun nh bc ni. Thc t nu trn ng B+ xut hin nhiu/ripple... th ti cng s xut hin theo ng t l ca bin p ch khng mt i.-Th nht: theo nguyn tc n nh, an ton, mch k v mch ng lc lun phi tch ri (c cch ly v in), v th ko nn dng chung ngun nu nh ngun ko phi l ngun n p v v cng ln so vi ti- Th 2: 7805 c th ko cng sut ko ci ng c, bn nn tra datasheet ca n so snh vi cng sut ti.- Th 3: ng c c th ko cn n p vn chy tt (nn chn ngun cp ph hp vi ng c, khng nn u thm phn n p vo gia, rt tn km, d chy nu ko tnh ton cn thn)Nu b ngun 12VDC ca mnh chia lm 2 nhnh song song:+ Mt nhnh mnh ni qua 7805 cp cho VDK.+ Mt nhnh mnh cp qua board cng sut ri cp cho ng c. Nu vy th ch c ng c l c thay i dng t ngt (khi iu xung).Vy cun dy ch t nhnh ng vo ca board cng sut ch u cn cp ng ra ca 7805, phi khng mi ngi ?Nhim v ch yu ca cun dy l lc cc gn nhiu cao tnBn trong cc ngun lun c con t 0.1uF (104) mc song song vi ngun. Con y mi lc nhiu tn s cao.T th cn tn s thp, cho tn s cao i qua. Nh vy nu xut hin nhiu tn s cao th ngay lp tc n qua t >>GND.Cun cm th ngc li. Cho tn s thp i qua, cn tn s cao. (ci ny n dng)Ci t y l ghp tng. N cho tn hiu i qua. V cn dng in 1 chiu, N c tc dng ngn ko cho dng phn cc tnh(dng DC) trong mch i ra v lm die ci my pht (my nghe nhc, VCD, DVD....)Vy nu mun xt chiu ca ci r th ta xt n dng 1 chiu. Bn no c p 1 chiu ln hn th mc vi + ca t.Nu mc ngc li th lu ngy s cht t. Tt nhin l phi rt lu v in p chnh lch gia 2 bn cc t rt b.http://www.dientuvietnam.net/forums/dien-tu-danh-cho-nguoi-moi-bat-dau-85/cuon-day-o-ngo-ra-mach-ap-dung-de-lam-gi-38824/index2.htmlnu in p c t ngt ln cao trong thi gian ngn cng ko nh hng n cu diode nh cc cun cm chn li

diot dng in xoay chiu sau khi c nn dng bng diode li c gi tr in p nhn vi cn 2diot ch yu l to dng mt chiu t dng xoay chiu do tnh cht ca lp chuyn tip p-n, n ch cho dng in chy qua theo mt chiu nht nhDiot l dng c dng trong nn dng. N c chc nng ch cho dng in i theo 1 chiu nht nh. Nh vy n c th bin dng in xoay chiu thnh dng in 1 chiu. Thng thng, ngi ta t hp nhiu diot li thnh mch nng cao cht lng dng in 1 chiu.Diode Zener c cu to tng t Diode, Diode Zener c ng dng trong ch phn cc ngc, khi phn cc thun Diode zener nh diode thng nhng khi phn cc ngc Diode zener s gim mt mc in p c nh bng gi tr ghi trn diode.

TRANSITOR 2BJT bo ho =>c 2 mu ni EB v CB u phn cc thunXc nh theo :Ib = Ic / beta (1)v : Rb = ( Vin - Vbe )/Ib.trong :Ib : dng phn cc chn BIc : dng ti chn C : Ic = (Vnguon - Vcesat)/ RcVcsat : n p Vce khi BJT dn bo ha ~0.3VRc : in tr ti chn Cbeta : h s khuych i dng ca BJT, thng thng ly gi tr thp nht theo data sheet Vbe : ngng in p Vbe ~0.7VTh d : Ic = 100mA; beta = 100~500; Vin = 10V th Rb #10K.BJT ngng dn =>c 2 mu ni EB v CB u phn cc nghcha) Mch khuych i ch A1) Transistor mc theo kiu E chung.L cc mch khuych i cn ly ra tn hiu hon ton ging vi tnC cc E u trc tip xung mass hoc u qua t xung mass thot thnh phn xoay chiuhiu ng vo.Tn hiu a vo cc B v ly ra trn cc CPhi nh thin sao choin p UCE~ 60% 70% Vcc.c nh thin sao cho in p UCE khong 60% 70 % VccBin tn hiu ra thu c ln hn bin tn hiu vo nhiu ln, nh vy mch khuych i v in pTn hiu u ra ngc pha vi tn hiu u vol ch A,ton k.b) Mach khuych i ch B.Mch khuych i ch B l mch ch khuych i mt na chu k ca tn hiukca tn hiumach khuych i ch B khng c nh thin.2) Transistor mc theo kiu C chung.Tn hiu a vo cc B v ly ra trn cc EV mi BE lun lun c gi tr khong 0,6V do khi in p chn B tng bao nhiu th p chn C cng tng by nhiu => v vy bin tnhiu ra bng bin tn hiu vo .Tn hiu ra cng pha vi tn hiu voCng ca tn hiu ra ICE= .IBEc) Mch khuych i ch ABL mch tng t khuych i ch B , nhng c nh thin sao cho in p UBE sp s 0,6 Vd) Mch khuych i ch CL mch khuych i c in p UBE c phn cc ngc3) Transistor mc theo kiu B chung.Ly tn hiu u ra l mt phn nh ca tn hiu u voTn hiu a vo chn E v ly ra trn chn C , chn B c thot mass thng qua t.quy nh ch ton k,c nh thinin p UCE~ 60% 70% Vccbn kkhng c nh thinUBE sp s 0,6 Vhay mt phnmc theo kiu nok in p,d hay cng sutng pha hay ngc pha

TRANSITOR mach lam vic trong vung khuch ai, mc ap trn chn B phai cao hn chn E khoang 0.6V (mi ni BE phai cho phn cc thun)va mc ap chn C cao hn mc ap chn B (mi ni CB phai cho phn cc nghich), thng mc ap trn chn C ly khoang 1/2 mc ap cua ngun nui. Dong lam vic cua transistor ly khoang 0.5mA la u.Mc in tr thnh cu phn p c c mt in p theo mun t mt in p cho trc.T ngun 12V trn thng qua cu phn p R1 v R2 ta ly ra inp U1, p U1 ph thuc vo gi tr hai in tr R1 v R2.theo cngthc .U1 / U = R1 / (R1 + R2) => U1 = U.R1(R1 + R2)Trong vng bo ha in p vCB < -0.4 V Thng chnh p vBE = 0.7V vCE bo ha = 0.1V n 0.3V

khuch i m tn 1Trn chn E thng c in tr nh mc dng lm vic cho transistor v n cng cn dng ly tn hiu hi tip nghch sa mo (khi ngang in tr khng gn t lc ha hc).Trn chn C c in tr nh mc p phn cc cho chn C (gi l in tr ly p) v n cng dng ly tn hiu ra trn chn C. Tn hiu ny qua t lin lc ng ra n ti hay vo cc tng khuch i tip theo.Trn chn B c in tr cp p phn cc cho chn B, n dng dn dng IB chy v ngun (dng IB rt nh nn cc in tr trn chn B thng c tr ln). Trn chn B c t lin lc dng ly tn hiu t ngun a vo mch khuch i. gii hn dy bin tn lm vic ca mch khuch i (ch gii hn cho lm vic trong vng m tn), ngi ta dng t hi tip nghch, cho ly tn hiu tn cao trn chn C tr v chn B, nn t hi tip trn chn CB c tr thng rt nh.( C nh)Mc p trn chn B thng cao hn chn E khong 0.6V ( l do tnh ghim p ca cc mi ni BE). Mc p trn chn B nn ly thp m rng phm vi lm vic cho mc p ca chn C (nn ly di 1.5V).Do tn hiu cho ly ra trn chn C, m tn hiu chnh l s bin i ca mc volt trn chn C.Vi cc transistor lm vic vi tn hiu nh Ic ly trong khong t 300uA n 1.2mAR3 ly tn hiu trn chn E v tn hiu ny to tc dng hi tip nghch, nn lm gim li(khuch i) ca mch, ng thi lm tng tr khng ng vo. Vi R3, li ca mch gim nn tn hiu ra t b mo hnT C3 (220pF) dng ly tn hiu tn s cao c trn chn C hi tip nghch v chn B, tc dng ny s lm gim li ca mch vng tn s cao, n thu hp dy tn lm vic ca mch. Nu tr ca t C3 ly cng ln ( C ) dy tn lm vic cng b thu hp nhiu hn. Trong thc t ngi ta thng dng t ny gi cho mch khng t pht sinh dao ng vng tn s cao.

khuch i m tn 2Kiu khuch i dng cu chia volt vi R1-R2 cp p phn cc cho chn B, nn n nh cao hn kiu 1R2 l in tr ly p. Tr R2 khng nn chn qu nh v n gy tn hao tn hiu ng vo.in tr R4 c cng dng nh dng. N nh mc dng chy vo chn E ca transistor.Dng lm vic ca transistor nn ly trong khong t 300uA n 1.2mA.Ngang R4 mc t lc ha C3, n lm mt tn hiu trn R4 b tc dng hi tip nghch gy ra do R4. in tr R5 dng ly tn hiu hi tip nghch, n c tc dng sa mo v tng tr khng ng vo.T C1 lm t lin lc ng vo v t C2 lm t lin lc ng ra. Tr s ca cc t lin lc c nh hng n bin tn hiu vng tn s thp. Cc t ny khng nn ly tr qu nh v s lm mt tn hiu vng tn thp. Cng khng nn chn qu ln, v dng r ca cc t ha ln s lm mch mt n nh.Thng mc t ha vo chn E ca cc tng tin khuch i, lm vy l b tc dng hi tip nghch vi tn hiu trn chn E.Cch ly phn cc DCKho st ng cong bin tn thy vai tr ca cc t in nh hng n dy tn lm vic ca mch.chng ta dng t C4 (120pF) l ly tn hiu trn chn C tr v chn B, l to tc dng hi tip nghch, vi tr ca t nh, n ch c tc dng hi tip nghch vng tn cao, khng nh hng n tn hiu m thanh, iu ny s lm nn bin cc tn hiu vng tn cao

khuch i m tn 3Kiu 3: Kiu mch khuch i dng 2 transistor cng loi lin lc thng.* n nh nhit rt tt.* H s khuch i cao, cho php dng ng hi tip nghch xu.* p ng bin tn tt.* Tr khng ng vo ln, nn t gy nng ti ln ngun tn hiu.Chn B c cp dng phn cc qua R5 (56K)Trn chn E c in tr nh dng R4Ngang R4 mc t lc ln C4 (220uF) b tc dng hi tip nghch AC trn chn E nhm tng cao li.Ngi ta dng t hi tip nghch AC C5 (5.6pF) nn bin tn hiu vng tn cao, gi cho mch khng b t kch vng tn cao.Khi cp dng lm vic cho cc transistor, Bn ch : Dng lm vic Ic ly nh th li km nhng t n v ngc li dng lm vic Ic ly ln th li ln nhng ting n, do dng chy pht ra, ln. Vi cc tng transistor lm vic vi tn hiu bin nh, dng lm vic thng ly trn di 1mA l hp l.Khi cp dng lm vic cho cc transistor, Bn ch : Dng lm vic Ic ly nh th li km nhng t n v ngc li dng lm vic Ic ly ln th li ln nhng ting n, do dng chy pht ra, ln. Vi cc tng transistor lm vic vi tn hiu bin nh, dng lm vic thng ly trn di 1mA l hp l.Kho st mch vi ngun tn hiu sinGhi nhn: Kiu mch khuch i ny c li rt ln (trn vi trm ln), do khi tng bin tn hiu ng vo ln 50mV, th tn hiu ng ra b mo (b vung ha), nguyn do l tn hiu ly ra trn chn C chnh l s tng gim ca mc volt, khi mc volt tng ln th khng th vt qu mc ngun (v lc ny transistor vng ngng dn, mt tnh khuch i) v khi mc volt trn chn C gim xung th khng th xung thp hn mc volt trn chn B (v lc transistor vng bo ha, mt tnh khuch i).Nhn Bn: C nhiu lc Bn cn c mt tn hiu c dng xung vung, Bn c th dng mch khuch i c li ln v cho tn hiu dng sin bin ln vo, n s cho Bn mt tn hiu dng xung vung ng ra. Ngi ta ni mch khuch i "vung ha" tn hiu.Kho st mch qua phn tch ng cong bin tn (Lc cha c t hi tip nghch trn chn CB ca Q2).Kho st mch qua phn tch ng cong bin tn (Lc c t hi tip nghch trn chn CB ca Q2)Mt trong cc cch nn bin tn hiu vng tn s cao hiu qu nht l dng t nh mc trn chn CB ca cc transistor to hi tip nghch.Kiu mch khuch i dng 2 transistor khc loi lin lc thng.y l kiu khuch i dng 2 transistor khc loi, mt npn v mt pnp cho ghp thng. c im ca mch khuch i ny l mch c tc dng hi tip nghch rt mch nn cho li nh, nhng b li tn hiu t b mo, d cho bin tn hiu vo ln.R5 l in tr nh dng cho Q2. Ngang R5 mc t lc C3 kh tc dng hi tip nghch tng li

khuch i vi saiu im ca mch khuch i vi sai l c kh nng khng nhiu cng sai rt mnh.c im ca kiu mch khuch i vi sai l mch ch khuch i cc tn hiu sai pha a vo 2 ng vo, vi cc tn hiu vo cng pha, mc volt bin i trn 2 chn C cng cng pha (cng ln hay cng xung) nn khng to dng in cp cho ti, ngoi ra vi mch bm dng hng (rp vi Q3), tr khng trn chn E chung ca Q1, Q2 rt ln, n to tc dng hi tip nghch rt mnh, cng lm tng kh nng khng nhiu tt hn. * R4, R6 l cc in tr cp phn cc cho chn B ca Q1, Q2, hai in tr ny thng ly tr bng nhau* R1, R2 l cc in tr nh p chn C v cng l in tr dng ly tn hiu ra trn chn C.* D1 l diode zener dng n ghim p v R3 l in tr nh dng lm vic cho D1.* R5 l in tr dng nh mc dng hng cp cho Q1, Q2.* C1, C2, C3 l cc t lin lc.Cch ly phn cc DC cho mch khuch i vi sai.Kho st mch khuch i vi sai vi ngun tn hiu sin, c tn s chun l 1KHz.