Vi tong cong suat day keo dung bien ap co nhieu nhuoc diem nhu o phan tich tren cho nen ngay nay trong cac may hien dai nguoi ta dung bien ap day keo k bien ap theo so do sau......

Dac diem co ban cua so do nay la 2 con den T1 va T2, nguoi ta dung 2 con den giong het nhau nhung cau tao khac nguoc nhau ve chieu dong dien

T1 la den thuan PNP thi T2 la den nguoc NPN nho vay ma mach dien co nhung uu diem sau:

Tu dau U vao tin hieu dc khuyech dai dc dan qua tu C o ban ky duong thi tin hieu vao thang cuc B cua con den T1,den nay lam viec o che do B va tai lay ra cua no o chan E o ban ky am tin hieu vao dc dan vao cuc B cua con den T2 day la con den nguoc nen U vao can dien ap.Vi vay T2 khuyech dai ban ky am cua tin hieu va T2 cung lam viec o che do B cho nen no chi lam viec voi ban ky am cua tin hieu dau ra co hien tuong cong tin hieu va tin hieu ra co day du ca 2 ban ky duong va am. Trong mach dien con co dien tro R1 va R2 con goi la dien tro dinh thien cho den T1 va T2, o chan E cua T2 dc dan ra phu tai chung voi C1 tai day co???????

Nhu vay uu diem dac diem cua mach nay la khong phai dung bien ap khong phai dao pha tin hieu vao nhung nhuoc diem la kho kiem dc 1 cap den (mot cap gom 2 den thuan va nguoc) thi cung kho dc tham so tuyet doi giong nhau , nhuoc dien thu 2 cua loai mach nay la phai dung nguon doi xung nhung cung chinh vi dung nguon doi xung ma lai co uu diem dac biet la khi dung nguon doi xung thu diem dau ra o chan E dau chung cua 2 con den dien ap 1 chieu =0V nen co the dau truc tiep voi phu tai nho vay toan bo tin hieu dau ra cua bo khuyech dai dc truyen den phu tai cho nen trong nhung bo khuyech dai cong suat cua cac tang am hien dai thi day la mach dc su dung nhieu nhat.

Neu khong muon dung nguon doi xung thi ta co the dung mach dien sau.......

So do nay van giong 2 so do tren cho nen con den T1 khuyech voi ban ky duong cua tin hieu vao va den T2 khuyech dai ban ky am cua tin hieu vao. Ca 2 deu lam viec o khuyech dai o che do B, tai cua no dc lay vao tu chan dau chung, chan E cua 2 con den bo nguon khong doi xung cho nen dien ap 1 chieu tai diem dau chung khac 0 thuong bang 1/2 tri so nguon

Vi vay muon dua tin hieu xoay chieu ra tai, nguoi ta phai dung tu hoa C de ngan cach . Tu nay khong cho 1 chieu di ra tai con xoay chieu thi qua tu nhung tro khang cua tu dc tinh bang Zc=1/wC

Muon thanh phan xoay chieu di ra dc tai thi Zc phai nho tuc la tai day ta phai dung C co tri so lon cho nen tri so tu hoa lon den muc nao di nua thi chat luong tin hieu ra cung khong bang mach dien tren

Ca 2 loai mach nay do khong chon dc 2 con den tuyet doi giong nhau cho nen 2 nua ban ky khong dc khuyech dai giong nhau cho nen meo.......

De khac phuc dieu nay nguoi ta dung tang khuyech dai cong suat day keo khong bien ap lam viec o che do A va B theo so do........

O so do nay nho phan ap cuc B bang 2 con diot D1 va D2 va dua ra cac dien tro on dinh R1 va R2 o chan E con den ma ta chueyn den T1 va T2 sang lam viec o che do A, B thi he so meo cua bo khuyech dai giam rat nhieu so voi mach truoc day

O nhung bo khuyech dai can cong suat dau ra cuc lon thi nguoi ta dau noi den cong suat theo kieu DALIRTON........

Dau den kieu nay la tin hieu dua vao cuc B den T1 khuyech dai ra o chan E den T1 roi no dc dua thang vao cuc B cua den T1 phay de dua ra chan E cua T1 phay

Beta= beta 1 x beta 1' (he so khuyech dai cua con den)

Cho nen cong suat ra cua con den nay la tang theo he so nhan

Muon tang cong suat cao hon nua nguoi ta dau theo kieu DALIRTON kieu bu.........

Dau noi den theo kieu DALIRTON thuong.

Trong so do DALIRTON kieu bu nguoi ta dung 2 con ban dan PNP va NPN nguoc nhau dau theo so do trong mach thi tin hieu dua vao chan B con den T2 duoc khuyech dai dua vao chan C den T2 se dua vao cuc B den T2' . Khuyech dai 1 lan nua cho nen dong dien ra rat lon, tat ca cac con den ban dan dung o day deu la loai so cong suat dat tien va trong khi lam viec voi dong dien rat lon thi no sinh nhiet rat nhieu.

Cho nen nguoi ta phai dat no len cac cach tan nhiet lam bang nhung tam nhom lon tham chi dung quat gio de tan nhiet. De bao ve nhung con so cong suat nay lam viec khong qua muc nguoi ta dua ra mach tu dong bao ve tang khuyech dai cong suat day keo khong dung bien ap theo so do sau......

Trong so do nay den T1, T2 la 2 con den khuyech dai cong suat kieu day keo khong dung bien ap . Phan ap cuc B cua no dung diot D1,D2 .CHan E co 2 dien tro on dinh nhiet do R1,R2 vi vay day la cap den cong suat lam viec o che do AB no la bo khuyech dai co he so meo nho nhat co do on dinh cao nhat vi phan ap giua chan B,C cua 2 con den T1,T2 la bo guong dong dien

Tu dong bao ve cho den cong suat T1,T2 (trong nhieu mach T1,T2 la cap den dau theo kieu DALIRTON kieu thuong hoac kieu bu) . Binh thuong 2 con den bao ve T3,T4 khong hoat dong khi den T1,T2 lam viec qua muc hoac phu tai dau ra qua cao dan den dong dien ra tang vot len lam cho sut ap tren R1 (UR1=+0.6V) va (UR2= -0.6V) thi luong dien ap nay se dan theo R3, R4 vao mo thong den T3 va mo thong con den T4. Chan C cua 2 con den nay lai dau vao cuc B cua 2 so cong suat cho nen no se khoa chat den T1,T2 hoac chinh cho T1,T2 lam viec yeu di thi bao ve dc T1,T2

1)Bien tan doi tan:

Cac bo tang am truoc day dung den dien tu thi hieu suat cua bo tang am chi dat dc 15%-20%

Khi dung den ban dan thi tang am dat hieu suat 40%-60%

Tang am ngay nay dung IC cong suat nguon co hieu suat 90%

2)Bien tan doi tan INVERTRR

Dung truc tiep dien 50Hz thi den Neon 40W phai them phan hao tren chan luu 36W thi 1 gio den Neon 40W tieu ton 40+36=76W

Ngay nay nguoi dung chan luu dien tu thi dau vao la 1 cau nan diot bo 50Hz bien 1 chieu thanh xoay chieu cao tan de qua bien ap chap nha tao 400V xoay chieu tan so cao de den Neon phong dien sau do lai dua ve 220V/50Hz thi 1 gio den neon dien tu chi tieu ton 40W

Het bai roi hehehehe...nho biet on chut nha(moi nguoi chi can mot coc nuoc :D)

Hiep_Ga