BÁO CÁO MẠCH ĐẾM

8/3/2019 BO CO MCH M

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TRNG I HC CNG NGH THNG TIN V TRUYN THNGKHOA CNG NGH IN T V TRUYN THNG

BI TP LN

BI :

Thit k mch m 8 bt

Ging vin hng dn: THS. Nguyn Vn Thng

Nhm sinh vin: Nhm 31. Dng Th Ngn

2. Dng Trung Ngha3. Bi Th Tnh4. Phm Th Hng Nhung5. on Vn Dng

Thi nguyn 11-2011

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Mc lc:

Tiu Trang

Phn tch thit k........................................................................

I.Cc linh kin s dng trong mch..

II. Cng dng, tnh nng ca tng linh kin trong mch

1.NE 5552.JK Flip Flop.

3.LED n..

4.T ...

5. in tr

6. logic XOR

III. Nguyn l v gii thch

IV. Mch in

V. Kt qu .................................................................................Kt lun v hng pht trin......................................................

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Phn tch thit k:

I. Cc linh kin s dng trong mch:

IC NE555 to dao ng JK Flip Flop

XOR LED n in tr T in

II.Cng dng v tnh nng ca tng linh kin

1.ic NE555

chc nng ca ic 555L thit b to xung chnh xc

My pht xung

iu ch c rng xung

iu ch v tr xung

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Chn 1: ni ra mass ny

dng cung cp cho IC

Chn 2: ng vo ca 1 tn s so p, mch so p dng cc

n bn dn thun (Mc p chun l 2*Vcc/3)Chn 3: Ng ra

Chn 4: dng lp nh mc trng thi ra. Khi chn 4 ni

mass th ng ra mc thp, cn khi chn 4 ni vo mc p

cao th trng thi ng ra tu theo mc p chn 2 va 6

Chn 5: dng lm thay i mc p chun trg IC theo VR hay

R ngoi cho ni mass. Tuy nhin trg cc mch ng dng chn

s 5 ni mass wa 1 con t t 10nF --> 100nF tc dng lc b

nhiu cho mc p chun n nh

Chn 6: ng vo ca 1 tn so p khc, mach so snh dng

cc Transistor ngc Vcc/3Chn 7: c th xem nh 1 kho in

Chn 8: Cp ngun` nui cho IC. Ngun nui cp cho IC

khon t +5V--> +15V , ti a l =18V

Cu to ca NE555 gm OP-amp so snh in p, mch lt v transistor x in. Cu to ca IC n gin nhng hot ng tt. Bn trong gm 3 in

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tr mc ni tip chia in p VCC thnh 3 phn. Cu to ny to nn in pchun.

in p 1/3 VCC ni vo chn dng ca Op-amp 1 v in p 2/3 VCC nivo chn m ca Op-amp 2. Khi in p chn 2 nh hn 1/3 VCC, chn S

= [1] v FF c kch. Khi in p chn 6 ln hn 2/3 VCC, chn R ca FF= [1] v FF c reset

Gii thch s hot ng:

K hiu 0 l mc thp bng 0V, 1 l mc cao gn bng VCC. Mch FF l loiRS Flip-flop,

Khi S = [1] th Q = [1] v = [ 0].

Sau , khi S = [0] th Q = [1] v = [0].

Khi R = [1] th = [1] v Q = [0].

Tm li, khi S = [1] th Q = [1] v khi R = [1] th Q = [0] bi v = [1],

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transisitor m dn, cc C ni t. Cho nn in p khng np vo t C, in

p chn 6 khng vt qu V2. Do li ra ca Op-amp 2 mc 0, FF khng

reset.

Giai on ng ra mc 1:

Khi bm cng tc khi ng, chn 2 mc 0.

V in p chn 2 (V-) nh hn V1(V+), ng ra ca Op-amp 1 mc 1 nn

S = [1], Q = [1] v = [0]. Ng ra ca IC mc 1.

Khi = [0], transistor tt, t C tip tc np qua R, in p trn t tng. Khinhn cng tc ln na Op-amp 1 c V- = [1] ln hn V+ nn ng ra ca Op-

amp 1 mc 0, S = [0], Q v vn khng i. Trong khi in p t C nh

hn V2, FF vn gi nguyn trng thi .

Giai on ng ra mc 0:

Khi t C np tip, Op-amp 2 c V+ ln hn V- = 2/3 VCC, R = [1] nn Q = [0]

v = [1]. Ng ra ca IC mc 0.

V = [1], transistor m dn, Op-amp2 c V+ = [0] b hn V-, ng ra ca Op-amp 2 mc 0. V vy Q v khng i gi tr, t C x in thng qua

transistor.

Kt qu cui cng: Ng ra OUT c tn hiu dao ng dng sng vung, c

chu k n nh

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Hnh 3.1.17 Cu trc mch ca FF JK

3. in tr

in tr c trng cho tnh cht cn tr dng in. Chnh v th, khis dng in tr cho mt mch in th mt phn nng lng ins b tiu hao duy tr mc chuyn di ca dng in. Ni mtcch khc th khi in tr cng ln th dng in i qua cng nh vngc li khi in tr nh th dng in d dng c truynqua.Khi dng in cng I chy qua mt vt c in tr R, innng c chuyn thnh nhit nng vi cng sut theo phng

trnh sau:

P = I2.R

trong :

P l cng sut, o theo W

I l cng dng in, o bng A

R l in tr, o theo

Chnh v l do ny, khi phn loi in tr, ngi ta thng da vocng sut m phn loi in tr. V theo cch phn loi da trncng sut, th in tr thng c chia lm 3 loi:

- in tr cng sut nh

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- in tr cng sut trung bnh

- in tr cng sut ln.

Tuy nhin, do ng dng thc t v do cu to ring ca cc vtcht to nn in tr nn thng thng, in tr c chia thnh 2loi:

- in tr: l cc loi in tr c cng sut trung bnh v nh hay lcc in tr ch cho php cc dng in nh i qua.

- in tr cng sut: l cc in tr dng trong cc mch in t cdng in ln i qua hay ni cch khc, cc in tr ny khi mchhot ng s to ra mt lng nhit nng kh ln. Chnh v th,chng c cu to nn t cc vt liu chu nhit.

tin cho qu trnh theo di trong ti liu ny, cc khi nim intr v in tr cng sut c s dng theo cch phn loi trn.

Cch c gi tr cc in tr ny thng thng cng c phn lm2 cch c, tu theo cc k hiu c trn in tr. Di y l hnhv cch c in tr theo vch mu trn in tr.

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i vi cc in tr c gi tr c nh ngha theo vch mu thchng ta c 3 loi in tr: in tr 4 vch mu v in tr 5 vchmu v 6 vch mu. Loi in tr 4 vch mu v 5 vch mu cch ra trn hnh v. Khi c cc gi tr in tr 5 vch mu v 6 vchmu th chng ta cn phi mt cht v c s khc nhau mt

cht v cc gi tr. Tuy nhin, cch c in tr mu u da trncc gi tr mu sc c ghi trn in tr 1 cch tun t:

i vi in tr 4 vch mu

- Vch mu th nht: Ch gi tr hng chc trong gi tr in tr

- Vch mu th hai: Ch gi tr hng n v trong gi tr in tr

- Vch mu th ba: Ch h s nhn vi gi tr s m ca 10 dngnhn vi gi tr in tr

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- Vch mu th 4: Ch gi tr sai s ca in tr

i vi in tr 5 vch mu

- Vch mu th nht: Ch gi tr hng trm trong gi tr in tr

- Vch mu th hai: Ch gi tr hng chc trong gi tr in tr

- Vch mu th ba: Ch gi tr hng n v trong gi tr in tr

- Vch mu th 4: Ch h s nhn vi gi tr s m ca 10 dng nhn

vi gi tr in tr

- Vch mu th 5: Ch gi tr sai s ca in tr

4 t in

T in l mt linh kin in t th ng to bi hai b mt dn in cngn cch bi in mi . Khi c chnh lch in th ti hai b mt, ti cc b

mt s xut hin in tch cng cng , nhng tri du.

S tch t ca in tch trn hai b mt to ra kh nng tch tr nnglng in trng ca t in. Khi chnh lch in th trn hai b mt l inth xoay chiu, s tch lu in tch b chm pha so vi in p, to nn trkhng ca t in trong mch in xoay chiu.

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5. LED n

LED pht quang c pht sng khi chng ta cp ngun cho n th n s

pht sng.

C rt nhiu LED pht quang vi mu sc, kch thc chng loi khc

nhau. V c ng dng trong thp sng, trang tr...

Bn cht ca LED chnh l mt diode c kh nng pht sng khi phn cc

thun. Khi Led sng thi in p ri trn LED c gi tr nh nht l 0.7V v

ln nht gn 2V ty tng loi LED. Ty vo tng loi LED m c gi trdng qua LED khc nhau LED sng bnh thng. Thng thng th

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ngun cp cho LED 3V th chng ta khng cn in tr hn dng nhng i

vi nhiu mch ngi ta khng th dng thm mt ngun na nn ngi ta

dng ngun cho LED chung vi ngun iu khin (5V) v lp thm con in

tr ni tip cho LED. Mc ch l hn dng cho LED khng cho dng quaLED ln hn gi tr nh mc. Nu m qu dng th LED s chy

III.Mch nguyn l:

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Gii thch nguyn l:

Nguyn l :

IV.Mch m phng:

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V.Mch in :

VI.Kt qu: mch thc t

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Kt lun v hng pht trin

Khi bin son bo co, chng em c gng cp nht nhng kin thc mi c lin

quan n mn hc, ph hp vi nhu cu hc tp tm hiu ca mi ngi cng nh yu

cu thc t. D vy khng th trnh khi nhng thiu st, nn chng em rt mong

nhn c s ng gp kin ca thy gio v cc bn ti liu c hon thin

hn.

Em xin chn thnh cm n!

THE END

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