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M~ch khuech d<.ti dung Transistor tnrang thmJng co hai cach mac co ban db la each mile clJ'c nguon chung (SC) va each mac qrc mang chung (DC) va ft khi co cach mac clfc ci'ra chung. Mac cue ngu6n chung (SC). Cach mac qrc nguon chung wang duang vOi each mac clfc E chung clla Transistor luang clfc. Nh~n biet each mac. Ta co the nh~n biet each mac clfc nguon chung dlfa vilo hai d~c diem sau:. www.Beenvn.com - download sach mien phi. - Di¢n lip tin hi~u vilo dlIqc dlIa vuo qrc G. Mqch klllle'ch d{li mac qrc nguoll c/tung. NhlI v~y, h¢ s6 khuech d~i di¢n ap cua Transistor trlIang chi bang mQl phan mlIai h¢ so khuech d<;li cua Transistor IlIang qrc. Ve m~t t~p am, ta thay rang dong di~n t<;lP am clla Transistor trlIang nha hem so vai dong di¢n t~p am cua Transistor llIang cl!c trong khi di~n lip t~p am co trj s6 cung b~c. NhlI v~y, vai ngu6n tin hi~u vim co n¢i tra cao thi dc Transistor twang deu c6 t~p am nha, con dc nguon tin hi¢u ~6 nQi tra thap thl t<).p am clla Transistor twang va Transistor llIang cl!c Ia nhlI nhau. - Sa do mac qrc mang chung co tra kha.ng vao lOn han nil nhieu so voi tra khang vao clla sa do mac cvc nguon chung, nhung di¢n dung vao cua.
Tra kha.ng ra cua sa do cI!c mang chung kh6ng nha nhu trang sa.
Cdp di¢n cho Transistor thlUjn dung nguon dU(1ug. + Di~n ap t~i elfe C eua Transistor Hl OV VI duqc noi tn,fc tiep ngu6n mat. www.Beenvn.com - download sach mien phi. Cap diftl clIO Transistor ngaqe dimg ngulm dl/mlg - Phil.n rfeh each cap di9n:. Cap ngllon eflo Transistor rhuqn citing ngudn am. www.Beenvn.com - download sach mien phi. - Philn tfeh each cap di~n:. Cal) ngllljn clIO Transislor ngu(fc dung ngu6n am. CHll DO C()NG TAc CVA PHAN nI KHUECH DAI. Transistor luang CI!C co ba tr~ng thai ho~t d¢ng: Tr~ng thai ngung dan,. Khi tfnh to<in dc di¢n tra phan cl!c cho Transistor co nghia I;) ch9n diem ho,-~t dong tinh Q (di6m lam vi(:c) cho Transistor do. Khi co tin hi¢u xoay chieu tac d¢ng van ng6 van CciIa vao, dau vao) clla Transistor thl di~m ho~t d(mg Q se bj diYi cho va lam thuy d6i cac thong s6 khac cib m<ctch. ho<ctt d¢og AB. Vung buo hoa PMAX. Vung khuech dl;ii. Vung ngLIng dan. Cae l'ung tam vi¢e Clla Transistor. www.Beenvn.com - download sach mien phi28. - Che d¢ hO':lt dOng C: Transistor duqc' phan cl!c cho di6m hO<;lt d¢ng tinh Q nam sau trong vung ngung dan. Transistor se duqc pM.n cl!c cho diem Q nam giua vung khucch d<;li va vung ngung dan. Sau day ta se khao sat tung twang hqp Cl,l th~:. Transistor IO':li Ge. Khi Transistor nh~n duqc tin hi~u xoay ehieu 6 Cl!C B thl dong di~n Is se b, thay d6i theo tin hi~u xoay chieu nay. Khi dong di~n If) bi thay d6i thea tfn hi¢u xoay chieu se lam cho dong di¢n Ie hi thay deli va keo thea di¢n ap VeE cung bj thay deli. hai ban chu ky cua tfn hi¢u xoay chieu hlnh sin),. nh~n duqc tfn hi¢u xoay chieu b qTc B thi chi co m¢t ban chu ky duqc khucch d~i. VI lam phan qTc tiep giap BE va IR tang len, con mQt ban chu ky lam giJm philn clfc tiep giap BE xu6ng vung ngung dan nen tfn hi¢u kh6ng duqc khuech d<;li. www.Beenvn.com - download sach mien phi. di~m ho~t d¢ng tinh Q nam tren duemg bien giUa vung khuech d'.li va vung nglffig dan, v C'E ~ V cc' Khi dong di~n If) tang len theo tin hi?u xoay chieu thl dong di?n Ie cGng lang len va la.m eho di¢n lip V CE ghtffi xu6ng. Df(ic tuyen ra J ehe'd(J hqat dqng AB. www.Beenvn.com - download sach mien phi. Khi Transistor nh~n duqc tfn hi¢u xoay chiell a cqc B lhi ban chu ky duang duqc rai VaG vimg gan nhu tuyen tfnh nen duqc khuech d~i. m<;tnh, biln chu ky am duqc rai VaG vUng dU?1 Vy nen Transistor kh6ng dan va kh6ng co tfn hi~ll ra. 6 che d¢ ho~t d¢ng nay thI chi co ban chu ky duang cua tin hi¢u duqc khllech d~i vi lam dong di¢n Ic tang len. - Transistor chi khuech d~ duqc m¢t ban chu ky, ban chu ky am rai vao vung ngtrng dan nen bien d¢ tin hi~ll ra bang 0. - Hi¢u suat cao do c6ng suat tieu tan nho. Khai ni~m va philn lo~i hoi tiep. Sa do kht/i mflc/z khue'ch dC}i co hoi lilp www.Beenvn.com - download sach mien phi. Yang he) tiep.
- Hoi tiep song song: Khi di~n ap nguon tin hi¢u va di¢n ap hoi tiep ghep song song v6i nhau (N6i each khac, khi hoi tiep song song la tin hi¢u vao va tin hi¢ll hoi tiep cung dua VaG m¢t qrc cua Transistor).
M<;lch dao d¢ng t<;lO faxung vuong di~n hloh va thuong hay g<}p nhat ia. Th6ng thuang ID'.lch da hili tl,l' dao dQng ill m'.lch d6i xung nen hai Transistor cung ten va cac linh ki~n di~n tnJ, t~ di~n co cung tri so. Tuy hai Transistor cung ten, d.c hnh ki~n cung trj so nh lIng kh6ng th~.
Khi mai cap di~n se co mot Transistor diin di~n m1.lnh han va m¢t Transistor dan di~n yeu han. Nha tac d.,lflg cua m1.lch h6i tiep duang lir C I ve BI va tit C2 ve B2 se lam cho Transistor da.n di~n m1.lnh han tien dAn den tr~ng thai bao hoa, Transistor dAn di~n yeu han tien dan den ngung dan. Dieu nay lam cho tl,l C I phong di~n qua Rhl va di~n ap am tren C I dLIa ve TI lam cho TI ngung dan.
Sau day ta se khao sat m¢t trong cae m;:tch dao d¢ng t<.to xung vu6ng la dao d¢ng tich thoat. Thai gian diÂn ap b vao dau vao dolo linã tang tir VB len V A ia khuech d~i thu~t toan b tr:;tng thai bao hoa duong, thOi gian diÂn ap dau vao dao linã giiim tu VA xu6ng VB la khuech d:;ti. Cac m~ch dao d¢ng duqc su dl:Jng lam ca.tZ m~ch t~o ra tin hi¢u song mang trong cac h~ thong thu phat tin hi~u, cac m~ch t~o tin hi~u quet trong cac thiet.
Hay trlnh bay nguyen Iy m9.ch dao d(>ng da Mi Slt dl,lng IC.
Giii dieu ehe'thea phuang phap nay e6 d¢ ehinh xae eao va e6 th~ thve hi¢n duqe bang vi m~eh. Cae phuang phap dieu che va giai dieu che' ASK, FSK va PSK eling duqc sir dl,lng trong eae h~ thong thu phat ttn hi¢u va dfr li¢u so trang eae h¢ thong tdng dui so. Tin hi~u mang muon duqc tach ra nho mQt b¢ lqc, tan s6 cua no thuang gqi.
De' tr¢n tAn, ta c6 the sir d~ng phan tir phi tuyen ha~c phin tir tuyen linh tham s6. - Khi phan la~i thea phan tit tich cl!c duqc dung de tr¢n tan, nguoi ta phan bi¢l tr¢n uin dung phan tit tuyen tinh tham s6 (m~ch nhan) va lr¢n tan dung phan tit phi tuyen (Transistor, diat. Môclt tr(in fdn dling dio!. trang m'.lch co xiiy ra hi~n tlIqng trQn tan nguqc. Mqch trQIl td'n can bang dung diot www.Beenvn.com - download sach mien phi. Trong m'.lch, di¢n ap tin hi~u duqc d~t len hai diot nguqc pha, con di¢n ap ngo'.li sai duqc d~t len hai diot dong pha. M'.lch tf9n tan Can bang co kha nang lam tang dong trung gian C1 dau ra va chong t'.lP am ngo'.li sai tot. Thanh phan cila tin hi¢u fa kh6ng co cac tan so b~c chan. M~ch trQn tan dung phan til khuech d~i. M'itch trQn tin dung Transistor va vi m'.lch la kieu tr9n tan dch cvc, su dl,lng Transistor ho~c vi m'.lch lam phan tu tf¢n tan. M'.lch tr9n Hin kieu nay co uu diem la co khii nang khuech d'iti tang cuang di¢n ap tin hi¢u fa. Trong philn nay. chi d~ c~p den c3.C m~ch tr¢ln tan dung Transistor, con tr¢n tan dung vi m~ch sc dUQ'C de C~lP tai b cac giao trinh khac. Mi.~ch tr¢n Uln dung Transistor c6 the mac theo sa do Baza chung ho~c Emitor chung. Sa dd Baza chung thuang duqc Slr dl,lng trang ph<;tm vi t.1n s6 eao va situ cao VI tan so giai h~n ella n6 cao. Ole tham so cua sa do tn)n tan phl,l thuQc vao die:m lilm vi~c, vao de) ICtn ella di~n ap ngo~i sai va vao tham so ella Transistor.
T1'Qn tan dung Transistor c6 th~ dung Transistor dan, Transistor mac theo kieu driy keo, nhung each dua cae tin hi¢u vao va hfy tin hi¢u ra lit kh6ng thay d6i. Tin hi~u trung gian duqc liiy ra tren cl!c eolector cua QI bang cach ghep bien ap. Khi kh6ng co tin hi~u dua VaG m'.lch thi di~n ap ngo;;ti sai tac d¢ng len hai cl!c Baza cua hai Transistor Ql va Q2 mOt luqng nhu nhau, do do dong di~n.
Khi co tin hi~u VaG Ulh va tin hi~u song mang U~m dua tai m'.lch thi hai tin. Cilng gi6ng nhu tron Hin can bang dung diot, m;;tch trOn tan ki~u nay kh6ng c6 thanh phAn hai b~c chan trong thanh phan tin hi~u ra.