tivi

BO GIAO DUC VA AO TAO

AI HOC QUOC GIA THANH PHO HO CH MINH

TRNG AI HOC S PHAM KY THUAT

KHOA IEN IEN T

BO MON IEN T

(((

E TAI:

SINH VIEN THC HIEN: TRAN VAN NGHA

LE KHAC SINH

LP: 95K

GIAO VIEN HNG DAN: LE VIET PHU

NGUYEN DUY THAO

Thang 03 nam 2000

BO GIAO DUC VA AO TAO

CONG HOA XA HOI CHU NHA VIET NAM

TRNG AI HOC S PHAM KY THUAT

OC LAP _ T DO _ HANH PHUC

KHOA IEN

BO MON IEN T

NHIEM VU LUAN VAN TOT NGHIEP

Sinh vien thc hien:

TRAN VAN NGHA

LE KHAC SINHLp:

95K

Khoa:

1995 2000

1. TEN LUAN VAN: THIET KE VA THI CONG MO HNH ANH PAN TI VI MAU

2. CAC SO LIEU BAN AU:

3. NOI DUNG CAC PHAN LY THUYET & TNH TOAN:

4. CAC BAN VE & O TH:

5. GIAO VIEN HNG DAN: LE VIET PHU

NGUYEN DUY THAO

6. NGAY NHAN NHIEM VU:

NGAY HOAN THANH NHIEM VU:

GIAO VIEN HNG DAN

THONG QUA BO MON

Ngay thang nam 2000

CHU NHIEM BO MON

NHAN XET CUA GIAO VIEN HNG DAN

NHAN XET CUA GIAO VIEN DUYET

LI CAM N

Co c thanh qua hoc tap nh ngay hom nay chnh la nh s tan tnh day bao cua qu Thay Co, Gia nh va Ban Be v vay Chung Em xin chan thanh biet n:

Quy Thay Co Trng H S Pham Ky Thuat

Thay Le Viet Phu, Thay Nguyen Duy Thao

Gia nh va Ban Be

Nhom Sinh Vien Thc Hien

Tran Van Ngha

Le Khac SinhMUC LUC

Li noi au

A. Muc ch va yeu cau:Trang 1

1. Muc ch

1

2. Yeu cau

1

B. Y tng thiet ke va phng phap thc hien

2

C. Cac bc thc hien

3

I. Thiet ke cac board khoi cua board A

5

1. Thiet ke board nguon on ap ngat dan

5

2. Thiet ke board cong suat quet ngang va FBT

12

3. Thiet ke board H.osc, V.osc

16

4. Thiet ke board cong suat doc

20

5. Thiet ke board Khuech ai sac va mach ghep CRT23

6. Thiet ke board khuech ai tn hieu choi

26

7. Thiet ke board giai ma mau Pal va NTSC

29

II. Thiet ke cac board khoi cua board B

34

1. Thiet ke board chuyen mach TV/AV

34

2. Thiet ke board Tuner

38

3. Thiet ke board SIF va cong suat am thanh

44

5. Thiet ke board vi x ly

50

III.Ket noi board A vi board B

55

IV.Thiet ke cac board trung gian

57

1. Y tng thiet ke va nguyen tac lam viec

57

2. Mot so v du cu the viec thc hien cac pan tren mot so board c ban

Ket luan

LI NOI AU

Ky thuat truyen hnh la mot lnh vc co lien quan va ho tr vi nhieu nganh khac nh: Tin hoc, y hoc, vien thong, quan s...

Ky thuat truyen hnh bao gom qua trnh thu, x ly va phat tn hieu hnh anh va am thanh. Qua trnh nay bien oi tn hieu quang thanh tn hieu ien va cuoi cung la tai tao lai thanh tn hieu quang c the hien tren man hnh.

Nh vay qua trnh hoat ong cua mot Ti Vi la mot qua trnh bien oi ngc vi qua trnh hoat ong may phat ve nguyen tac chung.

Do o neu hieu sau nguyen ly hoat ong cua Ti Vi th Sinh Vien co the hieu biet ve nguyen tac pha phat mot cach c ban nhat.

e hieu sau ve Ti Vi th ngoai viec hoc ly thuyet ky thuat truyen hnh, Sinh Vien can phai thao tac vng vang ve thc te.

Tren c s o Mo hnh anh pan TiVi mau c chon lam e tai phuc vu cho viec giang day thc tap ky thuat truyen hnh sau khi a hoc ly thuyet hoac co the dung e minh hoa, gii thieu cho Sinh Vien ang hoc ly thuyet ky thuat truyen hnh.

Thiet Ke Mo Hnh anh Pan Ti Vi Mau

A. Muc ch va Yeu cau:

1.Muc ch:

Nham ho tr cho viec giang day ly thuyet va thc tap ky thuat truyen hnh, "Mo Hnh anh Pan Ti Vi Mau" co the dung e minh hoa cac mach c ban tng ng vi tng khoi theo s o khoi cua Ti Vi mau hoac tao ra cac pan thong dung giup cho sinh vien ly luan va biet cach van dung ly thuyet vao cac mach thc te.

(Trong thc te co vo so Pan, t mot hien tng hong hoc co the do nhieu nguyen nhan gay ra do o sinh vien phai nam vng ly thuyet ky thuat truyen hnh c ban va suy luan e phan tch mi sa cac pan mot cach khoa hoc c)

Ngoai ra mo hnh co the dung giang day thc tap truyen hnh giup sinh vien cung co va hieu ro hn ly thuyet a hoc, luyen tap ky nang phan tch, ly luan t cac pan do Giao Vien tao ra tren mo hnh.

2. Yeu cau:

V mo hnh dung cho viec giang day nen viec thiet ke mach can theo cac yeu cau sau:

- Cac board mach phai phu hp vi cac khoi c ban nh ly thuyet a hoc.

- Han che toi a viec dung cac IC tch hp nhieu khoi lai vi nhau.

- Mach n gian, ro rang, de khao sat va o ac.

- Board mach va mo hnh co the tach ra hoac ghep lai de dang va co kch thc gon nhe.

- Vat t linh kien de tm tren th trng.

- Gia thanh tng oi co the chap nhan c.

B. Y tng thiet ke va phng phap thc hien:

e co the phu hp vi muc ch va yeu cau nh tren, mo hnh thiet ke gom 2 phan chnh:

1. Thiet ke mo hnh Ti Vi mau.

2. ong thi vi viec thiet ke cac board mach hnh thanh y tng tao ra cac pan.

Y tng tong quat ve "Mo Hnh anh Pan Tivi Mau" nh sau :

e giai quyet cac pan viec au tien can nhan nh va phan tch hien tng da vao s o khoi, nh vay can phai thiet ke moi khoi tng ng vi mot board mach rieng (board khoi ).

Sau o e mo hnh hoat ong can phai co mot board chnh e ket noi cac khoi lai vi nhau.

1. Muon mo hnh hoat ong th viec thiet ke cac board khoi phai c thiet ke va can chnh trc.

Viec can chnh can co cac thiet b sau:

VOM

Oscilloscope 25 MHz, 2 tia.

May phat tn hieu hnh chuan.

May phat song am tan.

Bo nguon on ap thay oi c : 1,25VDC 30 VDC/ 2A.

Cac board khi thiet ke can co cac iem th e o ien ap mot chieu va cac dang song tn hieu chuan.

Sau khi hoan thanh viec thiet ke va can chnh cac board khoi, giai oan tiep theo la thiet ke board chnh.

Board chnh gom 2 phan: (A & B)

Board A: Gom cac board khoi ket noi lai vi nhau thong qua cac e cam nh may Vi Tnh.

Nhiem vu board nay la ket noi vi CRT e tao ra khung sang va hnh anh tren CRT.

Board B: Gom cac board khoi ket noi lai vi nhau thong qua cac e cam nh mot may vi tnh.

Nhiem vu board nay co the thu song t ai phat hoac VCR va ong thi e ieu khien.

2. Y tng tao ra cac pan a c hnh thanh t cac board khoi nen cong viec cua phan nay la thiet ke cac board trung gian co cac cong tac chuyen mach bang tay tng ng vi cac pan co the xay ra trong mot board khoi.

C. Cac bc thc hien:

Cac board khoi c thiet ke da vao s o nguyen ly cua cac hieu TiVi khac nhau.

Viec thiet ke cac board khoi khong nhat thiet phai theo trnh t nhat nh, tuy nhien theo ly thuyet ky thuat truyen hnh a hoc va e de dang thc hien mo hnh th nen theo cac boc sau:

I. Bc 1: Thiet ke cac board khoi cua board A.

e tao ra khung sang tren man hnh can phai co en hnh va cac board mach tng ng.

- Mo hnh co the ket noi c vi cac loai en hnh 14 inch co nho nen can thiet ke board nguon on ap va mach cong suat quet ngang, FBT sao cho phu hp.

- Thiet ke board H.OSC, V. OSC.

- Thiet ke board cong suat quet doc.

- Thiet ke board khuech ai tn hieu sac va mach ghep noi CRT.

- Thiet ke board khuech ai tn hieu choi.

- Thiet ke board giai ma mau.

Ket noi cac board khoi tren vi nhau e board A hoat ong tot.

II. Bc 2: Thiet ke cac board khoi cua board B

Sau khi board A a hoat ong, cac board khoi cua board B se c thiet ke tiep theo trnh t sau:

- Thiet ke board chuyen mach AV / TV.

- Thiet ke board Tuner.

- Thiet ke board IF.

- Thiet ke board Audio.

- Thiet ke board vi x ly.

Ket noi cac board khoi tren lai vi nhau e board B hoat ong tot.

III. Bc 3:

Ket noi board A va board B sao cho mo hnh hoat ong va can chnh lai cho phu hp.

IV. Bc 4:

Thiet ke cac board trung gian gia cac board khoi vi board chnh va tren board trung gian co cac cong tac chuyen mach e anh pan.

I. Bc 1: Thiet ke cac board khoi cua board A

1. Thiet ke board nguon on ap ngat dan.

Mach c thiet ke tren mot board rieng ( phan diode nan ien va tu loc ien nam tren board chnh A ) va mach nay co the thay bang 1 board mach hoat ong theo nguyen ly kieu khac nhng thong so ky thuat phai phu hp.

e an toan cho Sinh Vien khi thao tac thc hanh, mach c thiet ke mass cach ly.

a. Thong so ky thuat:

- Vin : 130VDC 305VDC

- Vout : B+1: 115 V

- B+2: 16 V

- Pmax : 120 watt

- Tan so hoat ong cua mach: 30KHz 50 KHz

- o gn song tren ap mot chieu ( Ripple ) : 100 mVpp b. S o khoi:

c. S o nguyen ly:

d. Tnh toan va thiet ke mach:

Bien ap xung:

Bien ap xung hoat ong da tren hien tng cam ng ien t, loi cua bien ap la ferit nen ton hao t va hieu suat cao.

- Tnh dong nh cuon s cap bien ap:

Ipp = 2Po / VImin . max

ien ap DC nho nhat sau khi qua chnh lu:

VImim =100.1.4 =140V

ien ap DC ln nhat sau khi chnh lu:

VI max =260. 1,4 =376V

T so ien ap vao:

K = 376 / 140 = 2,62

max : chu ky lam viec ln nhat

Chon max = 0,7

Chu ky lam viec nho nhat ngo vao:

min= max/ (1- max ). K + max

= 0,7 / (1- 0,7 ). 2,62 + 0,7

= 0,47

Dong nh can tnh:

Ipp = 2. 200 / 140. 0,7

= 4,08A

Vay chu ky lam viec co gia tr trong khoang 0,47 en 0,7 khi ien ap ngo vao thay oi trong khoang t 140 VDC en 367VDC .

-Tnh chieu dai khe h:

ien cam s cap bien ap xung:

Lp = VImin .max/Ipp.f

Lp=140.0,7/4,08.20

=1,2.103H

The tch hieu dung cua loi:

Ve = 0,4 Lp. I2pp.108/B2max

Chon Bsat = 4000 gauss

Suy ra: Bmax =Bsat/ 2 =2000 gauss

Suy ra: Ve = 0,4.3,14.10-3.(4,08)2.108 /( 2000)2

Tiet dien loi bien ap xung Ae c chon: 0,96cm3

Chieu dai khe h:

Lg = Ve/ Ae = 0,63 / 0,96 = 0,64 cm

-Tnh so vong day quan:

So vong day quan cho mot volt la:

N = 108 / K.f.Ae.Bmax

Chon K =4

Suy ra n = 108 / 4.20.103.0,96.2000

= 0,7 vong/ Volt

So vong cuon s cap:

Ns =Vo.n =150.0,7 = 80,5 vong

Tnh c day quan:

Dong ien tai IL la:

IL =P0/ V0 =200/115 = 1,74 A

ng kn day quan:

D = 1,3.(IL/J)

J : Mat o dong ien

Chon J = 4 A/ mm2

Suy ra d =11,3 .(1,74/4) =0,75 mm

Vay ta chon c day t 0,7 en 0,8 mm

Tnh toan mach ien:

Chon transistor chuyen mach Q102

Nguon cung cap c tnh vi ien ap vao ln nhat:

VCC =260.2 = 367 VDC

Vay khi Q4 ngng dan th VCE cua Q4 at gia tr 367 VDC

Dong ien ngo ra cung la dong ien tai:

I0 = IL = P0/U0

Tra so ta chon transistor chuyen mach Q4 la 3688

Vay hai che o lam viec th ng vi:

ton1 = d1 / f = 0,82 / 20.103 = 41 s

ton2 = d2 / f = 0,34 / 20.103 = 17 s

toff1 = (1/f )/ton1 = (106/20.103 )-17 =3 s

Dong ien cuon cam phong qua tai:

Ipk1 = 2ILmax.[ 1+ (V0/V ) ]

= 2.1,774.[ 1+ (115/140)]

= 6,3A

Do vay tu loc co gia tr:

C1 = [(IPK1-IL)2.ton1.VImin]/2.VI.IPK1.V0

= [(6,3 - 1,74)2. 41.10-6.140]/2.100.10-3.4,66.115

= 8,23 F

C2 = [(IPK2- IL).ton2.VImax]/2.VI.IPK2.V0

= [(4,66-1,74)2.41.10-6.338]/2.100.10-3.6,3.115

= 457 F

e am bao an toan ta chon tu loc ien ngo ra co gia tr: 1000 F/180V

Tnh cuon cam :

L1 = [(VImin-V0).ton1]/ IPK1

L1 = [(140-115)].41.10-6/6,3

L1= 162,7 H

L2 = [( VImax- V0).ton2/IPK2

= [(338-115).17.10-6/4,46

=717,8 H

L2 > L1 nen chon L2 =717,8 H

L2 = .m / IPK2

Chon B = 0,4 T S= 0,85cm2

Suy ra: n = L2. IPK2 / B.S

= 717,8.10-6.4,66 / 0,4.10-4.0,85

= 98,4 vong

Thi gian cua chu ky xung:

T = 1 / f =1 / 20.103 = 50 s

Thi hang e tu nap ay co the lay t 30 en 100 chu ky xung

Chon 60 chu ky xung, va thi hang se la:

= 60. T = 60 .5 = 3000 s

Tnh bo loc ngo ra:

Chon tu loc ngo ra vi o gn song be nhat la:

V = 100 mV

Che o lam viec cua chu ky xung:

d = ( V0 + VD) / (VI + VD )

Che o lam viec cua chu ky xung vi ien ap vao thap nhat:

d1 = (115 + 0,7 ) / ( 140 + 0,7 )

= 0,82

Che o lam viec cua chu ky xung vi ien ap vao ln nhat:

d2 = ( 115 + 0,7) / (338 + 0,7 )

= 0,34

Mat khac: d = ton / ( ton + toff ) = ton / T =ton .f

Suy ra: ton = d / f : Thi gian dan cua transistor chuyen mach

toff = ( 1 / f ) - ton : Thi gian ngat cua transistor chuyen mach

e. Thiet ke mach in board nguon on ap ngat dan

2. Thiet ke board cong suat quet ngang va FBT

Board nay c thiet ke tren board A( Board chnh ).

Mach ien da vao s o nguyen ly a hoc, FBT cua may Thompson.

a. Thong so ky thuat:

- B+: 115 VDC cung cap cho FBT .

- Dong tieu thu khong tai: 100mA 150 mA (khong co CRT vaYoke H)

- Dong tieu thu khi co tai: 400mA 500 mA

- Bien o ien ap tn hieu fH ( t board H.osc ) vao tang H.drive 1Vpp

- Cac ien ap ra t FBT: (tng ng vi fH = 15khz17khz )

HV = 18 KV 22KV

ien ap Focus = 2 KV 3 KV

ien ap Screen = 500 V 800V

ien ap cung cap cho khuech ai sac ( sau khi qua nan ien va loc ien ): 200 VDC.

ien ap cung cap cho cong suat doc ( sau khi qua nan ien va loc ien):26VDC

ien ap ot tim: 18Vpp 22 VDC

ien ap cung cap cho tang AFC: 15Vpp 25 VDC

ien ap cung cap cho IC nh( memory ): -30 VDC (sau khi qua nan ien va loc ien).

b. S o khoi

c. S o nguyen ly:

d. Phan tch mach ien:

Dao ong ngang c a vao cc B cua trans tien khuech ai Q1 va Q2, nhiem vu chnh la phoi hp tr khang va tang dong tao ra dang tn hieu phu hp vi ngo vao cua tang cong suat ngang. 2 tu C1, C2 va R1 mac song song vi cuon s cap cua bien ap, e triet tieu dong Ic cua trans thuc Q1 khi b mat ien ot ngot.

Trans dung tang cong suat ngang Q2 dung loai trans ngat dan v no hoat ong che o xung e co the ong m nhanh. Khi xung dng cap vao cc B cua Q2 th co dong chay qua tu .47p. Khi Q2 ngat, dong khong bien mat tc th ma giam t t qua tu C3, C4, C5, sau o tu mi bat au xa qua cuon Yoke vi chieu ngc lai trc o. Khi tu xa het th xung c cap vao cc B cua Q2 va qua trnh hoat ong c lap lai.

e. Thiet ke mach in board cong suat ngang va FBT:

Board nay c thiet ke tren boad chnh A

3. Thiet ke board H.osc, V.osc:

Board nay dung IC LA7800 c dung trong cac TiVi Sanyo IC LA7800 bao gom cac khoi: Sync sep, AFC, H.osc, V.osc.

a. Thong so ky thuat:

- Vcc : 12VDC

- Dong tieu thu: 20mA 30mA

-V.osc out : 1Vpp

- ien ap tn hieu hnh vao: 1Vpp

- fH : 15Khz 17 Khz

- fv: 50 Hz 60 Hz

- H.osc out: 1 Vppb. S o khoi:

c. S o nguyen ly:

d. phan tch mach ien:

Khi co ien ap B+: 115V t board nguon on ap a en ngo vao 115V qua R18: 10k/ 5w, chan 15 IC LA 7800 c cap 12V, luc nay khoi dao ong cua IC LA 7800 ( chan 2 ) ket noi vi mach ien gom R2, R1, C3, va H.Hold (H.Hold ieu chnh fH thay oi c t 15 khz - 17 kHz ) se hnh thanh mach dao ong tao tn hieu xung vuong co tan so fH.

Tn hieu xung vuong nay c a ra chan 3, cung cap cho mach cong suat ngang va mach FBT hoat ong.

ong thi ien ap B2+: 16V qua ien tr can ien cung cap 12V cho khoi V.osc va khoi sync cua IC LA 7800 hoat ong.

Khoi V.osc chan 10, chan 11 ket noi vi R14, C10, R15,C15, C12, va V.Hold hnh thanh mach dao ong doc. Khi c cap ien 12VDC, mach V.osc dao ong tao tn hieu xung vuong fv : 50 Hz 60 Hz (bien tr V.Hold ieu chnh se thay oi c tan so fv), ngo ra khoi nay (chan so 6) tn hieu c a en board cong suat doc va (t board dao ong doc ) va tn hieu hoi tiep ve t chan 7, chan 8 cua IC.

Khi co tn hieu hnh toan phan a en chan 14, khoi sync sep se tach tn hieu ong bo ngang va doc, tn hieu ong bo ngang a en khoi AFC (ben trong IC). Chan 16 cua IC se nhan tn hieu xung rang ca (t FBT) thong qua mach tch phan R10, C6, R8 e so pha. Chan 1 la ngo ra khoi AFC, tn hieu ra se a en mach H.osc e ieu chnh tan so va pha sao cho phu hp vi tan so va pha cua tn hieu hnh.

Ngoai ra chan 4 cua IC ket vi R4, C8, D1 se hnh thanh mach bao ve qua ap. Mach se cat tn hieu fH ngo ra, khi ien ap a en PRT tang len.

e. Thiet ke mach in board H.osc, V.osc:

4. Thiet ke board cong suat doc:

Board nay dung IC PC 1378 thng s dung trong cac Ti Vi Sony, Nec.

a. Thong so ky thuat:

ien ap cung cap 24 VDC 27VDC

Dong tieu thu: 20mA 50mA

Bien o ien ap tn hieu vao: 1Vpp

Bien o ien ap tn hieu ra: 60 Vpp

b. S o khoi:

c. s o nguyen ly:

d. Phan tch mach:

Khi cap nguon 24 VDC vao chan 6 va xung fv t board V.osc vao chan 4 cua IC th mach se hoat ong. Mach khuech ai cong suat doc hoat ong lp B nh mot mach khuech ai cong suat am tan, do o can co 2 ng hoi tiep t board nay ve chan 7 va chan 8 IC LA 7800 ( t khoi V.osc ) e on nh che o lam viec.

ng mot: Ngo ra chan 2 ra york Vert ong thi qua R6, C20, VR100K ve chan 8 IC LA 7800.

ng hai: T au con lai cua York Vert qua mach C28, R29, C21, R27, R26, R25, R20, C9 va bien tr V.Height ve chan 7 cua IC LA 78000, bien tr V.Height dung e chnh chieu cao cua khung sang.

Tn hieu quet doc xuat ra chan so 2 cua IC ti York doc co bien o khoang 60 Vpp se tao t trng lech doc trong cuon York doc lam lech tia ien t trong ong phong CRT theo chieu doc.

Ngoai ra chan 7 cua IC tn hieu V.Blank thong qua mach R va C ( noi tiep) se cung cap cho board mach khuech ai Y e xoa hoi va cung cap xung fv cho IC onscreen tren board vi x ly.

e. Thiet ke mach in board cong suat doc:

5. Thiet ke board khech ai sac va mach ghep CRT:

a. Thong so ky thuat:

Nguon cung cap 180 VDC.

ien ap cung cap cc B 3 trans Khuech ai sac: 5VDC 7VDC.

Bien o ien ap tn hieu Y: 7Vpp

Bien o ien ap cung cap ot tim 20Vpp ( xung dng ).

ien ap cung cap li G2: 200VDC 500VDC.

ien ap cung cap li G3:( Vao e cam uoi CRT ): 2KV.

Mach hoat ong kieu hieu so mau: R-Y, G-Y, B-Y.

b. s o nguyen ly:

c. Phan tch mach:

Ba tn hieu sac ER, EG, EB ra t IC giai ma mau AN5625 c a vao cc B cua Trans cong suat Q353, Q352, Q351 trong luc tn hieu choi -EY da vao cc E cua 3 trans cong suat noi tren.

Ngo ra cua Q353, Q352, Q351 qua bien tr VR 2K7 1/2W tai cc C c a thang vao 3 catot en hnh se la ER, EG, EB. Li 1 chung noi mass, li 2 va li 3 cap ap dng lay t cuon HV.

ng tn hieu choi -EY vao Q351 c gi lam chuan hai ng choi Q352 va Q353, c hieu chnh bang 2 bien tr R371 va R369 tc la thay oi bien o -EY a vao cc E cua Q351 va Q353.

Mc tn hieu a vao cao, co ngha la tn hieu ra cung cao va dong tia cua en hnh cung ln. Thay oi 2 chiet ap nh vay la thay oi mc cao nhat cua dong tia B va R sao cho chi tiet sang nhat cua anh ( mc EY cao nhat ) th 3 ong phong R, G, B co cng o ung ty le e tao ra anh sang trang mat en hnh.

ong thi tn hieu onsreen t vi x ly a en R1, C1 vao cc E cua Q1 lay ra cc C cua Q1, vao cc B cua Q2 va lay ra cc C cua Q2. Tn hieu onscreen sau khi qua tang em Q1,Q2 c a t cc C Q2 vao cc B cua Q353 sau o a vao KB en hnh.

d. Thiet ke mach in board khuech ai sac va mach ghep CRT

6. Thiet ke board khech ai tn hieu choi:

Mach nay neu s dung IC AN 5615 th mach se n gian hn, tuy nhien rat kho can chnh va phoi hp vi tn hieu vao, va cac khoi lai tch hp trong IC nen chon giai phap s dung trans.

Mach dung trans thiet ke se phc tap hn nhng viec phoi hp tong tr va can chnh se tr nen de dang hn.

a. Thong so ky thuat:

Vcc: 12VDC.

Dong tieu thu 10mA 20mA.

ien ap tn hieu vao: 1Vpp.

ien ap tn hieu ra (Y): 7Vpp 10 Vpp.

ien ap tn hieu V.Blank: 20Vpp.

ien ap tn hieu H.Blank vao: 20 Vpp.

b. S o nguyen ly:

c. Phan tch mach:

Tn hieu video composite c a ti Q1, C1 cach ly thanh phan DC t tang trc.

Q1lam nhiem vu cua tang em, ngo ra cua Q1 tn hieu c a en Q2vaQ3.

Q2, Q4 la nhiem vu ieu khien thanh phan DC cua tn hieu video, ieu chnh mc sang toi tren man CRT nh bien tr R35

Q3 phoi hp vi mach C6, L3, L10 va L1,C2, R7, C1 nang ap tuyen tan so cao cua tn hieu choi, ong thi ieu chnh bien tr Con trast se lam thay oi bien o tn hieu choi.

Tn hieu choi t ngo ra cua mach Q3 ( thong qua C6 )va thanh phan DC cua tn hieu choi ( Q2, Q4 ) se a en cc B cua Q5.

Tai cc B Q5 ap DC t ngo ra ABL mach FBT se t ong khong che che o lam viec cua Q5 khi CRT hoat ong qua manh.

Q5 lam nhiem vu khuech ai ao pha tn hieu choi va a ti Q6.

Q6 ong vai tro nh mot tang em ong thi tron cac tn hieu V.Blank ( t board V.Amp ) va H.Blank ( lay t FBT ) e xoa ng hoi ngang va doc tren CRT.

d. Thiet ke mach in board khuech ai tn hieu choi:

7. Thiet ke board giai ma mau: Pan va NTSC

a. Thong so ky thuat:

ien ap cung cap Vcc: 9 VDC 12VDC ( chan 11 ).

Dong tieu thu cua board: 40mA 60mA.

Cac ien ap can thiet cung cap cho board mach:

Tn hieu hnh mau: 1Vpp ( chan 7 IC )

Xung fH khoang 10Vpp ( chan 2 IC )

H.Sync khoang 10 Vpp ( chan 14 IC).

V.Sync khoang 10Vpp ( chan 18 IC ).

ien ap cho phan ieu chnh bao hoa mau: min 6V (chan 8 IC).

ien ap chnh Tint: 0 VDC - 12 VDC ( chan 9 IC )

ien ap cung cap chan 19 thay oi 3 cap tuy theo IC giai ma mau he tng ng :

Vcc: He Pal

1/2 Vcc: He NTSC 3,58

0VDC: He NTSC 4,43

b. s o khoi:

c. s o nguyen ly:

d. Phan tch mach:

Phan tch cac khoi trong IC:

Tang khuech ai cong loe co nhiem vu loai bo tn hieu khong can thiet, ch gi lai tin tc loe mau. Khuech ai cong loe ch m ra ung luc khi co loe mau.

Mach dao ong tan so 4,43 MHz va 3,58 MHz nham tao song mang phu thc hien viec giai ma.

Mach ACC (auto color control ): la mach ieu khien tn hieu mau, mach ACC co ket cau giong mach AGC. Nhng tn hieu mach AGC la video va AGC on nh bien o video, con tn hieu ACC la loe mau va ACC la mach e on nh bien o tn hieu sac.

IC giai ma mau c s dung trong mo hnh la AN5625, trong IC khong co x ly tn hieu choi Y.

Nhiem vu cua tang Killer: khi tang nay do khong thay tn hieu nhan dang Ident cua he mau, no se lam tat mach mau e tranh nhieu mau khi thu hnh en trang. Khi muon giai ma mau th may thu phai tao lai c thanh phan song mang phu mau ( nh mach dao ong ).

Burst gate can lay xung m cong a vao chan so 14 e tach lay tn hieu burst. Phan 1H FF dung ao pha song mang phu theo dong, nh o giai ma c tn hieu.

Mach Blank lay xung xoa, xoa ng hoi doc va hoi ngang e on nh hoat ong cua mach giai ma mau.

Phan tch mach ien cua board:

Tn hieu mau tong hp c a en mach ( BPF ) mach cong hng loc lay tn hieu song mang mau, tn hieu nay a vao chan 7 IC AN 5625 en khoi BPA khuech ai dai thong.

Ngo ra khoi PBA tn hieu mau qua khoi ieu khien bao hoa ( color control ), ieu chnh bien tr color chan 8.

Tn hieu c lay ra chan 5 va thong qua VR2, C2 a en chan 3 ong thi qua day tre ( DL1H ), C4, R18, DL1, C1 en chan 1.

Tai chan 3 tn hieu mau c a en khoi burst gate e tach tn hieu (burst ) ong bo mau khi co xung t Flyback a en. Tn hieu a en APC- det e so pha va tan so cua 2 tn hieu : tn hieu tao ra t khoi dao ong tao song mang phu mau 4,43 Mhz hoac 3,58 Mhz ( chan 15, 16, 17) va tn hieu ong bo mau t tn hieu mau tong hp.

Neu co s sai pha th khoi APC - det se a tn hieu sai biet ve khoi dao ong tao song mang phu mau e sa sai pha cua tn hieu dao ong cho ung vi pha cua tn hieu ong bo mau.

Neu sai tan so hoac sai pha qua nhieu ( ngoai pham vi hoat ong cua mach ) khoi APC se tac ong vao khoi color killer e khoa mau .

Sau o tn hieu ngo ra t khoi osc 4,43Mhz; 3,58 Mhz se a en khoi giai ieu che R-Y, B-Y a en khoi Matrix e tai tao lai 3 thanh phan hieu so mau R-Y, B-Y, G-Y va a ra chan 20, 21, 22.

Ngoai ra tn hieu mau t chan 3 con a en khoi system SW noi lien vi chan 19.

Neu chan 19 at trc mc ien the bang Vcc (12V) va tn hieu mau a vao la tn hieu Pal 4,43 Mhz qua khoi 1HFF th ngo ra khoi system SW cho ra tn hieu a vao khoi Delay Line Matrix va qua khoi STFF ket hp vi tn hieu mau qua C2, VR2, va delay 1H a vao chan 1 e khoi nay hoat ong he Pal.

Neu chan 19 c at mc 0 V th mach se hoat ong che o giai ma NTSC 4,43Mhz.

Neu chan 19 c at mc ien the 5V th mach se hoat ong che o giai ma NTSC 3,58 Mhz.

Khi mach hoat ong che o NTSC 3,58 Mhz hoac 4,43 Mhz th chan 9 c noi vi bien tr ben ngoai e sa sai pha (bien tr Tint).

Chan 2 nhan tn hieu flyback puls, khoi 1H FF hoat ong.

Chan 18 nhan tn hieu V. Blank va H.Blank e xoa ng hoi doc va hoi ngang.

e. Thiet ke mach in board giai ma mau

II. Thiet ke cac board khoi cua board B:

1. Thiet ke board chuyen mach TV/ AV:

IC c dung trong board la IC TC 4066 gom 4 cong tac va cac chan ieu khien .

a. Thong so ky thuat:

SW1 chan 1-2 : Chan ieu khien 13 -Audio cua TV.

SW2 Chan 3-4: Chan ieu khien 15 - Video cua TV.

SW3 chan 8-9: Chan ieu khien 6 - Audio cua VCR.

SW4 chan 10-11: Chan ieu khien 12 - VideoVCR.

ien ap cung cap: 12V

Dong tieu thu: Vai mA .

b. s o khoi:

c. s do nguyen ly:

d. Phan tch mach:

IC chuyen mach 4066 co 4 cong tac 1 v tr va cac chan ieu khien ieu khien.

SW1: Chan 1-2 chan ieu khien 13 ( Audio Tivi )

SW2: chan 3-4 chan ieu khien 5 ( Video Tivi )

SW3: Chan 8-9 chan ieu khien 16( Audio VCR )

SW4: chan 19-11 chan ieu khien 12 ( Video VCR )

Tn hieu t au may a vao cc E cua Q1 va a ra cc C qua tu lien lac C3 en cc B Q2 va lay tn hieu ong pha ra cc E e en chan 10 IC chuyen mach (SW4 ).

Tn hieu video t khoi khuech ai trung tan video en chan so 3 IC chuyen mach.

Tn hieu audio sau khoi tach song FM en (SW2) chan so 1 IC chuyen mach (SW1 ).

Tn hieu video out cua au may va cua Ti Vi ra chan 11va chan 4. Hai chan nay c noi chung vi nhau en cc B trans buffer va lay ra cc E a en khoi giai ma.

Tn hieu audio cua au may va cua Ti Vi ra chan so 9 va chan so 2. Hai chan c noi chung vi nhau va a en khoi khuech ai am tan va a ra loa.

Hai trans Q5 va Q6 c ket noi nh s o. Cc B cua Q5 c ieu khien bi khoi ieu khien. Khi IC ieu khien tac ong mc thap th Q5 ngng dan, ap Vc Q5 bang VCC tac ong vao chan 5 va chan 13 mc cao luc nay SW2 va SW4 ong lai, may lam viec che o au may.

Khi cc B cua Q5 c tac ong mc cao lam Q5 dan manh, ap Vc cua Q5 giam lam Q6 ngng dan, ap Vc cua Q6 mc cao gan bang Vcc, tac ong vao chan 6 va chan 12 lam SW1 va SW3 ong lai nen may hoat ong che o Ti Vi.

Chan 14 : Noi nguon 24V.

Chan 7 noi mass.

e. Thiet ke mach in board chuyen mach Ti Vi / AV

2. Thiet ke board tuner:

Board nay dung tuner cua may Toshiba, hoat ong vi tan so cua IF theo tieu chuan OIRT.

a. Thong so ky thuat:

Cac chan ra cua tuner theo qui c so th t :

1 - IF.

2 - chan trong

3 - B+: ien ap cung cap 9VDC-12 VDC .

4 - AFT.

5 -SW chuyen mach do board vi x ly xuat ien the ieu khien BU hoac BV.

6 - ien ap thay oi t 0 - 30V t board vi x ly cung cap e do ai.

7 - BU : ien ap cung cap cho khoi UHF trong tuner hoat ong.

8 - BV: ien ap cung cap cho khoi VHF low va high hoat ong .

9 - AGC: ien ap AGC t board trung tang cung cap

b. S o khoi:

3. Thiet ke board trung tan hnh:

IC c dung e thiet ke la TA 7607.

a. Thong so ky thuat:

Vcc: 12 V.

Dong tieu thu: 15 mA.

Ngo vao can cung cap:

Tn hieu IF t ngo ra tuner.

Tan so IF.

Ngo ra cung cap: ien ap RF AGC cho tuner: 5V 7V.

ien ap AFT cho tuner: 4V 8V.

ien ap tn hieu hnh mau toan phan: 1Vpp.

ien ap SIF: 1Vpp.

b. S o khoi:

C. S o mach:

d. Phan tch mach ien:

Tn hieu trung tan t IF out cua bo tuner qua cuon day L1 va R5 mac song song e loc nhieu, sau o qua tu lien lac C en trans tien khuech ai Q1. R4, R6 cau phan the cua Q5.Tn hieu c lay ra cc C cua Q1 qua tu lien lac C3 en bo loc SAW, loc lay tn hieu IF chuan ong thi loai bo tn hieu cua cac kenh lan can. Sau o tn hieu trung tan a en chan so 1 va 16 cua IC 7607. Tn hieu t chan so 2 va chan so 15 cung a vao tang khuech ai trung tan.

Mach LC se cap cho dao ong tan so chuan cho mach tach song qua 2 chan 7 va 8. Khoi tach AFT gom mach dao ong LC a vao chan 7 va chan 10 cua IC. Tn hieu t khoi AFT ra chan 6 vao mach dao ong trong tuner e on nh tan so. Sau o tn hieu qua mach loc nhieu vao khoi tach song video, tn hieu nay c khuech ai nh khoi khuech ai tn hieu hnh. Tn hieu hnh toan phan c lay ra chan so 12 cua IC.

Chan 11 cap nguon 12 VDC

Chan 13: Mass.

e. Thiet ke mach in board trung tan hnh

4. Thiet ke board SIF va cong suat am thanh:

Board SIF:

IC c dung la PC 1382 thng co trong cac TiVi Nec, Sanyo,Toshiba.

a. Thong so ky thuat:

Vcc: 12 V.

Dong tieu thu khoang 12mA.

Ngo vao can cung cap.

-Tn hieu SIF (t board SIF ).

-ien ap ieu khien khoi AFT e ieu chnh am lng tn hieu audio (chan 8 ).

Ngo ra cung cap:

- Tn hieu audio cho mach cong suat am thanh.

b. S o khoi:

c. S o nguyen ly mach:

d. Phan tch mach ien:

Tn hieu SIF c lay t ngo ra khoi video, Qua (trap) tieng CF2 tng ng vi tan so trung tan tieng. Tuy theo tn hieu SIF can s dung, trap CF2 co gia tr tan so tng ng tan so se cho qua, sau o tn hieu nay a en chan 14, qua R35 en chan 13 a vao khoi Limiter.

ngo ra khoi nay trung tan tieng se qua mach loc thong dai (LPF : Low Pass Filter ) va c a qua khoi tach song FM.

Ngo ra khoi Det tn hieu am tan a c tach ra, va ra chan 5 a vao khoi ATT ( chan 4 ) sau o c a qua khoi tien khuech ai va ra chan 2 en khoi khuech ai cong suat am tan ra loa tai tao lai am thanh.

Chan 8: ieu khien am lng volume.

Chan 9,10: Co thach anh CF3 co tac dung cong hng tan so 6,5 Mhz e tach tn hieu am tan.

Chan 1: Cap nguon 12V.

Chan 7: Mass.

Board cong suat am thanh:

a. Thong so ky thuat:

Vcc: 12V.

Dong tieu thu: 12mA.

Cong suat 3 Watt

b. S o khoi va s o nguyen ly mach ien:

c. Phan tch mach:

IC s dung cho tang cong suat nay la TBA 810. Tn hieu am thanh t chan 2 IC UPC 1382 hoac tn hieu audio t au may qua bien tr volume tang giam tn hieu, sau o qua tu lien lac C9 vao chan 8 IC. Chan 7 co tu C8 xuong mass. Chan 1 la chan cap nguon 12V, C1: tu loc nguon, chan 9 va chan 10 noi mass.

Tn hieu sau khi qua khoi khuech ai trong IC c lay ra chan 4 qua tu suat am C4 lam thanh mach hoi tiep.

e. Thiet ke mach in board SIF va cong suat am thanh

e1. Thiet ke mach in board SIF

e2. Thiet ke mach in board cong suat am thanh

5. Thiet ke board vi x ly: board nay s dung vi x ly MN 14838, IC nh MN 1224, IC thc hien chc nang Inverter va IC thc hien chc nang giao tiep LA7930.

a. Thong so ky thuat:

Thong so ngo ra:

Cung cap ien ap do ai BT cho khoi Tuner.

Xuat cac ien ap ieu khien: BU, BVH, BVL.

Chuyen oi Ti Vi/ AV

Nguon

Am lng volume

Xuat tn hieu onscreen a len board CRT dung e hien th.

Thc hien chc nang nh kenh khi do ai.

Thong so nhgo vao:

Cung cap cac loai nguon: 5V, 16V, -30V.

Xung fH, fV : a vao e thc hien chc nang ong bo giai ma.

Vi x ly hoat ong vi tan so xung clock 500 khz.

Dong tieu thu t 60mA - 80 mA

b. S o khoi vi x ly:

c. S o nguyen ly:

d. Phan tch mach:

e board vi x ly hoat ong th viec au tien can cap nguon 5V, nguon nay c lay t IC 7805 cua board nguon va nguon -30V, 15V cap trc cho board vi x ly.

Khi IC vi x ly a hoat ong, neu tac ong vao cong tac S701 th chan 14 cua vi x ly xuat 5V en trans Q5, trans Q8 cua board nguon on ap xung. Hai trans Q5, Q8 dan bao hoa th nguon B+1: 115V va B+2: 16V se cung cap cho toan mo hnh hoat ong.

Khi mo hnh a hoat ong th viec ieu khien cac chc nang nh:

- Volume ( ieu khien am lng ) tac ong S2, S4.

- Chuyen kenh: Tac ong S1, S3.

- Chuyen trang thai TV / AV S702.

- On - off: S701.

- Do ai: au tien nhan SW2 sau o tac ong S712 va S710 e nh kenh va do ai xong can nhan S711.

IC memory can cung cap cac nguon ien ap 5V cho chan 2 va ngon -30 V cho chan 3.

IC giao tiep MB 88301 can cung cap cac nguon ien ap: 5V cho chan 16. IC nay co nhiem vu bien oi cac lenh xuat ra t IC vi x ly thanh cac mc ien ap cung cap cho cac board tren mo hnh .

IC vi x ly M50435 - 893FP thc hien cac chc nang:

Chuyen mach VL ( chan 25 ), VH ( chan 24 ), VHF ( chan 23 )

Chuyen TV/AV ( chan 18 - 16 )

Onscreen (chan 3,4 )

On/ off ( chan 14 )

Volume ( chan 27 )

e. Thiet ke mach in board vi x ly:

III. Ket noi board A va board B:

Ket noi board A va board B sao cho mo hnh hoat ong va can chnh lai cho phu hp.

1. Boad A: S o v tr cac board khoi tren board A

2. Board B: S o v tr cac board khoi tren board B

IV. Bc 4: Thiet ke cac board trung gian gia cac board khoi vi board chnh va tren board trung gian co cac cong tac chuyen mach e anh pan

1. Y tng thiet ke va nguyen tac lam viec:

Viec thiet ke cac board trung gian e anh cac pan thong dung c thc hien sau khi 2 board A va B a c can chnh va ket noi cho mo hnh TV hoat ong tot.

Cac board trung gian thc chat la board noi gia cac board khoi vi board A hoac board B. Tren board nay cac ng noi t board khoi xuong board A hoac board B thong qua cac cong tac chuyen mach e chuyen v tr ong hoac h.

T o se xuat hien cac pan do Giao Vien at ra, Sinh Vien can o ac va lien he vi kien thc Ky Thuat Truyen Hnh a hoc.

2. Mot so v du cu the viec thc hien cac pan tren mot so board c ban

oi vi board dao ong V.osc, H.osc

Cong tac SW1 h: Board mat nguon H.osc mo hnh ngng hoat ong.

Cong tac SW2 ong: Mass (thong qua trans) th mat H.pulse hnh anh b mat ong bo ngang.

Cong tac SW3 h: Mat tn hieu V.osc dan en board cong suat doc, hien tng con ng sang ngang tren en hnh.

Cong tac SW4 ong: Tn hieu H.osc out ( thong qua trans) b mat cung dan en mo hnh ngng hoat ong do mat HV.

Cong tac SW5 h: Mat tn hieu video t board chuyen mach AV a en, hien tng mat ong bo ngang va doc tren man hnh.

oi vi board cong suat doc:

Cong tac SW6 h: Mat nguon 24VDC cung cap, hien tng con ng sang ngang tren board man CRT.

Cong tac SW7 h: Mat tn hieu V.osc t board dao ong V.osc, hien tng con ng sang ngang tren CRT.

Cong tac SW8: H mat ng hoi tiep tren khung sang CRT hnh b co lai mat tuyen tnh.

3. Nh vay Sinh Vien khong the oan mo vo can c bang cach chuyen mach cac SW, ma can phai o ac phan tch e do ra cac pan t cac hien tng xuat hien tren man hnh.

Ket luan

Mo hnh anh pan Ti Vi mau c thc hien vi thi gian, ieu kien kha khiem ton va kien thc con nhieu han che nen chac chan con thieu sot, chung em rat mong moi nhan c y kien xay dng cua quy Thay Co, cac ban Sinh Vien e ngay cang tien bo.

ay la mot e tai tng oi kho vi chung em, nhng a c hoan thanh la do s hng dan tan tnh cua thay Le Viet Phu, thay Nguyen Duy Thao cung vi no lc ban than Chung Em.

Mot lan na Chung Em xin chan thanh biet n Qu Thay Co a giup , giang day trong thi gian hoc tap va hoan thanh e tai.MO HNH ANH PAN TI VI MAU C THIET KE DA TREN

S O KHOI CAN BAN CUA TI VI MAU

TAI LIEU THAM KHAO

- Television Hand Book

K.Blain Benson

Color Tivi Training Manual HOWARD W SAMS

Tai lieu giang day ly thuyet va thc tap truyen hnh cua Thay Le Viet Phu. EMBED MS_ClipArt_Gallery

Phan t chuyen mach

Nan va loc

Dao ong va ieu chnh tan so xung

Ap chuan

Ap tham chieu

Phan t ieu khien

Vi x ly

ien ap DC

(sau khi nan ien va loc ien)

Do sai

Phan t cam bien

Nan va loc

Bien ap xung cach ly mass

Phan t chuyen mach

FBT

16V

115VDC

Khuech ai thuc

Khuech ai cong suat

Cuon quet doc

Chnh dang xung

Hoi tiep ve mach choi H.osc V.osc

Vi x ly

V.Blank

H.Blank

Flyback

Boi ap

Nan loc

Cuon quet ngang

Khuech ai cong suat

Bien ap cong hng

Khuech ai thuc

FH t mach h.osc

fV

115V

ABL

T ong han che o sang

Mach bao ve

Heater

200V Khuech ai cong suatsac

-30V ti IC nh

15

14

13

12

11

10

9

16

AFC

Sync sep

V.osc

V

Blank

Shut down circuit

H.osc

V.drive

8

7

6

5

4

3

2

1

IC TA 7607

Board cong suat doc

Board cong suat ngang va FBT

Board dao ong doc

Board choi

Board nguon on ap xung

Board giai ma

Board Tuner

Board chuyen mach AV

Board trung tan hnh

Board vi x ly

Board SIF va am thanh