bao-cao-thuc-tap-dao-dong-hinh-sin

8/14/2019 bao-cao-thuc-tap-dao-dong-hinh-sin

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Trng i Hc Bch Khoa H NiKhoa in

====o0o====

TRUNG TM THC HNH IN T

BO CO THC TPMCH DAO NG HNH SIN

Gio vin hng dn : Nguyn Xun Lan

Sinh vin thc hin : Lu Nh Ho

Nhm : 9

Lp: iu Khin T ng KSTN K50

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BI MCH DAO NG* Nhim v thc hnh:

Nhim v bi thc tp ny l lp rp mch to dao ng hnh sin da trnnguyn l ca mch to dao ng kiu cu Wien, to ra dao ng hnh sin c bin nh - nh t 2,2V n 2,6V v tn s c sai s nh hn sai s cho php ( 15%).

I- S nguyn l :

Trong cc thng s ban u:R 1 = R 9 = 100k v R 2 = R 3 = 10kR 6 = 220k 320k v R 4 = R 5 = R 7 = R 10 = 560 1.2k

R 8 = 1.5R 11 = 4.7kVR = 2k 10kC1 = C2 = C8 = 10nF (103) v C3 = C4 = C5 = C6 = C7 = 10FT1 = T2 = T3 = C828

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II- S lp rp:

III - Cu to cu mch : Mch bao gm 3 khi chnh:- Khi khuych i chnh T1 v T2 mc EC.- Khi hi tip cu vin to dao ng.- Khi khuych i m.

a) Khi khuych i chnh:- Hai n T1 v T2 thuc loi C828 mc theo kiu EC do h s khuch

i ln hn 1 v hai n u lm vic ch A.- T ha C4 l t ni tng- Cc in tr R 1, R 4, R 5 dng phn p cho n T1.- Cc in tr R 6, R 7, R 8 dng phn p cho n T2.- T C5 dng n nh dng 1 chiu.

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- T C3 v bin tr VR hi tip ni tip in p (hi tip m xoay chiu)lm thay i bin ra cu tn hi .y l mch sa dng xung. b) Khi to dao ng :

n T1: T1 hot ng nh c dng hi tip dng t cc C ca T2 a v. Dnghi tip dng c a qua mch lc tn s mc theo kiu cu Wien gm t C1,C2 v in tr R 2 v R 3.

R3

R2

C1

C2

vao Ra

Cu WienTa c cng thc tnh tn s ca mch cu vin RC

2 3 1 2

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f R R C C

Nu ly R 2 = R 3 = R v C2 = C1 = C th tn s dao ng s l RC

f 21

0

c) Khi khuych i m:- C6 l t ghp tng,t C8 lm nhim v chng nhiu,n T3 mc CC, do hs khuych i K 1,nn khng nh hng ln n bin v dng xung ra.

- Cc in tr R 9, R 10 dng phn p cho n T3- T C7 dng trit tiu dng mt chiu u ra- in tr R 11 dng ly in p ra.

IV- Nguyn l hot ng ca mch1 - iu kin dao ng:

- iu kin cn bng pha: 2 KD v 0 PH 2 PH KD

- iu kin cn bng bin :K K.K PH 1

2 - S hot ng ca mch:

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- Khi cp cho mch mt in p 9V DCV, c hin tng hi tip dng gy tkch B T1 sau c khuych i qua T1. T1 lm vic ch A, mc EC nnqua T1 thu c 1 tn hiu ngc pha vi tn hiu BT1.

- Tn hiu ny c a n T2, c khuych i ln tip (T2 cng lm vic ch A v mc EC) thnh tn hiu ra ng pha vi tn hiu BT1.

- T1 v T2 mc theo kiu EC, trong T1 lm nhim v dao ng a hi c hitip dng, n T2 ch yu lm nhim v khuych i.

- T3 c tc dng nh dng c mc theo kiu CC, do c h s khuych i bng 1, tn hiu vo v ra l ng pha.

V- iu chnh mch:- Lp rp mch theo s cho trn, cha lp rp VR vo mch.- Kiu tra mch ni vi s lp rp,ch cc t ho phi c lp ng

chiu a) iu chnh ch mt chiu:

- Ngt ng hi tip dng v m v T1: ngt 1 chn t C2 v cha lp bin tr

- Dng ng h thang DCV (2.5V hoc 10V) o UBE v UCE ca 3 n.Cc gi tr in p phi iu chnh tho mn cc iu kin sau:

Ch : UCE cu T1 c in p xp x ngun l do hin tng t kch ca hi tip (+) av.

T1 T2 T3UBE(V) 0.5-0.55 0.55-0.63 0.55-0.63

UCE(V) 7.5-8.3 3.8-4.5 3.8-4.5

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- Cc gi tr o c khi cha iu chnh:

Nhn xt: Cc gi tr no cha t yu cu cn iu chnh li theo quytc:Mun gim UBE ta tng R B ,mun tng UCE th tng R B hoc gim R C (hocR E ).Gi tr R E1 chnh cng ln trong khong cho php cng tt v khi bin in p ra s ln.

Sau khi t c cc gi tr in p t yu cu,ta o in p ra xoay chiu.b) o in p ra xoay chiu:

- Hn li ng hi tip dng ( ni li t C2)- o in p u ra Ura, iu chnh ng h thang 10V ACV . Ta c

Ura > 1.5V . Nh vy l mch c dao ng, quan st dng in p trnOscilloscope thy c dng xung vung

- Lp bin tr VR vo mch,. iu chnh bin tr VR tn hiu ra c dng

sin

T1 T2 T3UBE(V) 0.7 0.7 0.82

UCE(V) 8.5 0.2 3

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R 6 (= R B2) = 462 k ;R 9 (= R B3) = 220 k ;R 4 = 1.5 k ;R 5 = 1k .Cc gi tr cnli khng .

V I - Kt qu : in p mt chiu:

in p ra c bin : U- = 2.7V

Tn s ca tn hiu sin thu c : 1 1 1351.43.7 0.2

f Hz T ms

Em xin chn thanh cm n gio vin hng dn hng dn tn tnh chochng em trong qu trnh thc tp bi ny.

Sinh vin thc hinLu Nh Ho

T1 T2 T3UBE(V) 0.52 0.58 0.62

UCE(V) 7.6 4 4

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