mach giao tiep thue bao-new

8/4/2019 Mach Giao Tiep Thue Bao-new

1/15

Trng i hc Bch Khoa H Ni

Vin in T - Vin Thng

====o0o====

BO CO THC TP

KHO ST MCH GIAO TIP THU BAO

Ging vin hng dn :

Sinh vin thc hin : Hong S Tn - 20083473Nguyn Th Hng - 20081327

Lp : in t 3-K53

H Ni, 09/2011


2/15

NI DUNG BO CO

I. Tm hiu h tng i SPC1. Gii thiu chung v tng i SPC

Tng i in t SPC (Store Program Controller ) l tng i c iu khin theochng trnh ghi sn trong b nh chng trnh iu khin lu tr. Ngi ta dng b vi

x l iu khin mt lng ln cng vic mt cch nhanh chng bng phn mm x l

c ci sn trong b nh chng trnh. Phn d liu ca tng i - nh s liu thu

bao, bng phin dch, x l a ch thu bao, thng tin nh tuyn, tnh cc - c ghi

sn trong b nh s liu. Nguyn l chuyn mch nh trn gi l chuyn mch c iu

khin theo chng trnh ghi sn SPC. Nhim v ca tng i l :

- Bo hiu : Trao i bo hiu vi mng bn ngoi, bao gm mng cc ng dy thubao v mng cc ng dy trung k u ni vi cc tng i khc.

- X l bo hiu v iu khin cc thao tc chuyn mch : C nhim v nhn thng tin

bo hiu t mng ng dy thu bao v cc ng trung k x l, pht ra cc thng

tin iu khin iu khin thit b chuyn mch v cc thit b ph tr khc to tuyn

kt ni, cp cc ng bo hiu n thu bao.

- Tnh cc : Chc nng ny tnh cc cho ph hp vi tng loi cuc gi, c ly... sau

khi cuc gi kt thc.

2. S khi ca tng i SPC Cu trc ca tng i SPC ni chung nh hnh 1:

1. Giao tip thu bao, giao tip trung k

2. Thit b ngoi vi, bo hiu

3. Thit b ngoi vi chuyn mch

4. Thit b iu khin trung tm

5. Thit b giao tip ngi myNgoi ra tng i quc t cn c cc khi : tnh cc, thng k, ng b mng, trung tmx l thng tin, thit b giao tip thu bao xa.


3/15

Hnh 1 : S khi tng i SPC

4 5

Thit bChuyn Mch

ng dy thubao

Trung k tng t

Trung k s

Bo hiuknh

chung

Bo hiuknhring

Thit bphn

phi bohiu

Thit bo th

trng thing

dy

Thit biu khin

u ni

BUS iu khin

B x ltrung tm

B nh

Thit btrao i

I/O

1

2 3

Thit b kt niMch ng dy


4/15

3. iu ch xung m PCM K thut iu ch xung m PCM (Pulse Code Modulation) l kt qu thu c cacc th tc x l ri rc tn hiu tng t theo thi gian, lng t ha theo mc tn hiuv m ha i lng mc lng t ca tn hiu thnh cc t hp m nh phn tng ng.Qu trnh thng tin PCM c minh ha nh hnh v :

Hnh 1 : Tuyn thng tin s

K thut PCM bao gm 3 bc:

+Ly mu:

Ly mu chnh l qu trnh ri rc ha tn hiu tng t. y l bc chuyn tn hiu

mang thng tin dng lin tc thnh tn hiu mang thng tin ri rc, bng phng php lymu (Sampling), sao cho tn hiu ri rc phi mang y thng tin ca tn hiu tng

t, ti to c thng tin mt cch trung thc u thu.

Qu trnh ri rc ha tn hiu s lm cho tn hiu lin tc thnh mt dy xung PAM

+Lng t ha:

L thay th mt tn hiu tng t c ly mu bng tp hu hn ca cc mc bin

, tc l bin i tn hiu lin tc theo cc mc thnh tn hiu c bin ri rc. u

im ca lng t ha tn hiu ly mu l gim c nh hng ca tp m. Cc mc

tn hiu ri rc ny gi l mc lng t ha, khong cch gia hai mc lng t ha gi

l bc lng t

+M ha tn hiu:

Sau khi lng t ha xung PAM, mi xung PAM s c lng t ha theo 8 bits.

Trong c 1 bit du v 7 bit s liu

4. Chuyn mch s T,S kt hp tng i in t, h thng chuyn mch l mt b phn ct yu. N c nhng chc

nng sau :

+ Chuyn mch : Thit lp tuyn ni gia hai thu bao trong tng i vi nhau hay

gia cc tng i vi nhau.


5/15

+ Truyn dn : Da trn c s tuyn ni c thit lp, thit b chuyn mch thc hin

chc nng truyn dn tn hiu ting ni, s liu v tn hiu bo hiu gia cc thu bao vi

nhau vi cht lng cao.

Cc phng thc chuyn mch:

+ Chuyn mch thi gian (T): l chuyn mch trn nguyn l trao i v tr khe thi gianca tn hiu PCM vo vi tuyn PCM ra ca b chuyn mch thi gian

+ Chuyn mch khng gian (S):cu to ca b chuyn mch khng gian gm mt ma

trn tip im chuyn mch kt ni theo khiu hng v ct. Cc hng u vo cc tip

im chuyn mch c gn vi tuyn PCM vo. Cc ct u ra ca cc tip im

chuyn mch to thnh cc tuyn PCM ra. Ta c mt ma trn chuyn mch khng gian c

kch thc nxn, s tuyn PCM vo bng s tuyn ra.

+ Chuyn mch kt hp:nu hai loi chuyn mch c a vo ng dng ring r th

hiu qu kinh doanh khng cao do tng i s c dung lng nh. iu dn ti khng

c tnh kinh t. khc phc nhng nhc im trn, cc nh sn xut nghin cu

phi ghp cc trng chuyn mch S v chuyn mch T to nn trng chuyn mch c

dung lng ln. Cc loi chuyn mch kt hp : T - S , S - T , T - S - T , S - T - S , T - S -

T - S v T - S - S - T.

Vi cc li chuyn mch trn, ngi ta cn c vo s lng thu bao m s dng tng

loi chuyn mch cho thch hp.

-S lng thu bao t th c th s dng chuyn mch T - S , S - T.

-Chuyn mch S - T - S thch hp cho tng i c quan PABX (dung lng hn

ch v tng S c th gy ra tn tht bn trong).

-Chuyn mch T - S - T thch hp cho tng i c dung lng thu bao ln v

c a vo s dng rng ri trong thc t. Do s dng tng T u vo nn hn

ch c suy hao.

-Chuyn mch T - S - T - S v T - S - S - T c s dng cho cc tng i c s

thu bao ln hn.


6/15

II. TM HIU MY IN THOI C NH1. S KHI MY IN THOI C NH

Trc khi tm hiu nguyn l hot ng ca my in thoi c nh, trc tin tatm hiu s qua v cu to bn trong my in thoi c inh.S khi ca my in thoi c nh nh sau:

Khi chngqu p

Khi chuynmch Hook

Khi chngo mch

Khi khain t

Khi thoi

Khi chung Bn phmKhi quay

s

Linetelephone

T hp nghe ni

Hnh 1: S khi mch my in thoi c nh

Line telephoneL ng dy ni gia tng i v my in thoi gm 2 dy: T (Tip) v R

(Ring) Khi chng qu p

L nhng linh kin bo v my in thoi khi ng dy c p cao hay st.Cc linh kin thng dng l Diac v Diot Zenner.

T

RDiac

T

R

DiodeZener

Hnh 2: Khi chng qu p

Khi chuyn mch Hook(chuyn mch nhc/ t)C nhim v phn bit mch thu chung v cc mch cn li

Khi chng o ccL cu Diot c tc dng duy tr cc tnh ca dng in trong mch my in

thoi. Khi kha in t

Gm 1 nhm Transistor c nhim v:- Khi ng ngun cho mch my in thoi.- Phn ngun cho mch thoi v mch quay s.- Lm kha in t ng m to ra xung trong qu trnh quay s kiu xung

thp phn (pulse) Khi thoi


7/15

c tch hp trong 1 IC thoi c nhim v:

o Khuch i m tn vo ra.

o Cn bng sai ng chuyn i 2 dy/4 dy.

o Mch kh trc m (kh ting ni t MIC lt vo tai nghe)o Mch lc nhiu v mch lc cao tn.

Hnh 3: Khi thoi

Khi quay s:

Hnh 4: Bn phm in thoi

- c tch hp trong IC s c chc nng:

o Gii m bn phm.


8/15

o Pht xung (quay s kiu xung thp phn).

o Pht t hp cao tn (quay s kiu t hp cao tn).

- Khi nhc my tng tr ng dy gim, tng i cung cp mc p l ~12V/30mA

- Cc loi tn hiu xut hin khi nhc my:

o Tn hiu mi quay s : 350->440Hz lin tc.

o Tn hiu bo bn: 480->620Hz: 0,5s ON ; 0,5s OFF.

o Tn hiu hi chung: 440->480Hz: 1s ON; 3s OFF.

Khi chung

Hnh 5: Tn hiu chung

- Xung chung c dng hnh sine, tn s 25 Hz v xut hin theo chu k 6s: 2sON v 4s OFF

Hnh 6: S khi mch chung in thoi


9/15

- Bnh thng ng nghe c gc trn my s tc ng ln Hook-SW lm cch limch in thoi ra khi ng dy, lc ny ch c mch chung c ning TIP, RING. Khi cha c xung chung, do c t cch ly => mch chungkhng c cp ngun => khng to ra m thanh loa.Khi c xung chung:dng AC c chnh lu lc v n p to in p khon 28V cp cho IC

chung => m thanh loa.

Hnh 7: S nguyn l ca khi chung

- IC chung ML8205:

o Chn 2: thay i m lng.

o Chn 3,4: to dao ng tn thp.

o Chn 6,7: to dao ng tn cao.


10/15

S nguyn l ca mch my in thoi c nh:

Hnh 8: S nguyn l my in thoi c nh

2. NGUYN L HOT NG CA MY IN THOI C NH

phn tch hot ng ca my in thoi c nh ta c th chia lm 3 ch :- Ch ch (t hp t)- Ch chung (c tn hiu chung)

- Ch hot ng (t hp nhc)a. T hp t(ch ch)

Ngun cp t tng i ti my 47 -> 53V DC, vi tng i t nhn th ngun cp nyl 25 -> 30V DC.

ch ch, chuyn mch Hook lm ngn mch quay s v m thoi, mch thuchung c ni.


11/15

Do ngun cp ca tng i l ngun 1 chiu nn b t C1 ngn li, khi thu chungcha hot ng cho ti khi c tn hiu chung (xoay chiu) t tng i gi ti.

b. Ch chung(khi c tn hiu chung)Khi my khc gi n, tng i gi tn hiu 75V 25HZ n (gi 2s ngt 4s). Ngun

cp t tng i sau khi i qua khi chng qu p c i qua mch tr khng cao (gmin tr R1 v t C1), mch ny c tc dng lc chung (h p in p chung) n 35 40V, c i qua chnh lu v cp cho IC chung lm IC chung hot ng

IC chung gm 8 chn, ngun t tng i c cp cho chn 1, chn 8 ni ra loa phtchung (c qua chuyn mch gm ba in tr R6, R7, R8 iu chnh m lng).

Cc chn 2, 3, 6, 7 c ni vi mch R, C c tc dng iu chnh m sc chung.

c. Ch hot ng(t hp nhc)Khi ta nhc ng nghe ln, chuyn mch Hook ngn mch khi chung v ni 2 u

dy vi khi quay s v m thoi.Ngun cp t tng i qua khi chnh lu cu v khi chung o cc v chng qu

p ti chn B ca Transistor Q1 lm transistor ny m, lm chn C ni vi chn s 9 caIC phm n mc thp iu khin cho IC ny hot ng.

Khi ta n phm bm, IC ny s pht xung (vi quay s kiu xung) chn s 10 hoct hp a tn (quay s kiu t hp a tn) chn 11 gi ti IC thoi v tng i.

Quay s kiu xung (PULSE)Khi chuyn mch P-T t P, th chn s 4 ca IC phm s mc cao (xc lp quay

s kiu xung).

Nu ta bm phm, IC phm s iu khin pht mt dy xung thp phn tng ng chn s 10. Tn hiu xung ny c gi ti tng i v ti IC thoi (to ting ku khi ta

bm phm) thng qua khi kha in t.Qu trnh gi tn hiu xung l qu trnh ng m cc transistor trong khi kha in

t c dng nh sau (minh ha cho trng hp n phm 2)

Quay s kiu t hp a tn (TONE)Khi chuyn mch P-T t T, chn s 4 ca IC phm s mc thp (xc lp quay s

kiu t hp a tn).

Nu ta bm bn phm, IC phm s iu khin pht chn s 11 t hp 2 tn hiu mtn (c mt tn s cao, c mt tn s thp). T hp tn hiu m tn ny c gi ti chns 7 ca IC thoi (to ting ku khi ta bm phm) v tng i.

Tn hiu quay s c a v tng i v tng i gi tn hiu chung n s my tacn lin lc. Nu my kia bn, tng i gi v tn hiu bo bn. Nu u kia nhc my,qu trnh m thoi in ra.

Qu trnh m thoi:


12/15

Khi ta ni, tn hiu t mic c gi ti chn 11 v chn 12 ca IC thoi, tn hiu thoira chn s 1 ca IC thoi qua khi kha in t c gi ln tng i.

Tn hiu thoi t u dy bn kia c gi t tng i, qua khi kha in t ca vo IC thoi chn s 9, qua IC thoi c gi ra ng nghe ti chn s 14 v 15.III. MCH GIAO TIP THU BAO

1.S nguyn l mch giao tip thu bao:

Hnh 9. Mch giao tip thu bao

2. Phn tch nguyn l hot ng ca mch giao tip thu baoCc linh kin, gi tr linh kin s dng trong mch giao tip thu bao:

in tr Transistor Diode Rle TR1 = 10KR2 = 100 R3 = 47 R4 = 47KR5= 10KR6 = 100

Q1=TIP41CQ2=Q3=C935

D1=D2=D7=D8=1N4007D3, D4: diodezenner (3.9V)D5D9 = led

Ls1=Rle C1=47FC2= 22FC3= 220F


13/15

R7 = 10KR8 = R9 = 5R10 = 470

Chc nng ca cc linh kin trong mch GTTB (Phn tch theo tng khi chc nng)

- Khi ngun: (B) gm R1: in tr phn p vo chn B ca Q1

C1: lc ngun v dn xoay chiu.

Q1: To ra in p cp cho mch.

D3: n p dng in 3.9V t vo chn B ca Q1.

R2: in tr n nh nhit.

D1: chng in p ngc cho Q1.- Khi bo v qu p (O): bao gm D4, D5: khi c in p co t ng dy thu

bao i vo mch th khi 2 diode ny s thng ngt mch xung t bo vton mch.

- Khi gim st (S): bao gm R5, R10, D9, Q2, R6. C3, D7

R10: hn ch dng R9.

D9: ch th trng thi lm vic ca my in thoi.

Q2: c tc dng nh 1 kha in tr.

R6: phn p cp vo chn B v C ca Q2.

C3: lc ngun v dn xoay chiu.

D7: chng in p ngc t vo B v ca Q2.

Khi thu bao nhc t hp th s c dng chy: t +30V qua CE ca Q1 qua R2 quachuyn mch LS (3 ni 4) qua R8, qua thu bao, qua R9, qua R6, xung t. Khi Q2c cp ngun s thng th n led s sang, bo hiu thu bao ang lm vic.

- Khi chung: bao gm R7, Q3, D8

R7: hn ch dng cho Q3.

Q3: tc dng nh kha in t.

D8: chng in p ngc t vo Q3.Khi c tn hiu chung t tng i a ti qua R7 t vo B ca Q3, lm Q3 thng khi cun dy 1 2 s c cp ngun, n s ht tip im 3 ni 5 ca LS1. Khi in p

25HZ 75V qua R3, LS1 (3 ni 5), qua R8 ti thu bao v bo hiu c cuc gi ti.IV. Mch gii m DTMF:

1. S nguyn l mch DTMF:


14/15

2. Phn tch nguyn l:

Khi in thoi c quay s, khi quay s s gi xung ti tng i. tng i c

mch gii m xc nh nhng phm s c nhn. Mch trn chnh l mch giim cc tn hiu .

Kt qu gii m nh sau:


15/15

mach giao tiep thue bao-new

Documents