Gii thiu:

Ni dung thc tp l thit k mch n in p mt chiu s dng cc linh kin c bn nh transistor, in tr, diode, t in vv. n p lm vic ch tuyn tnh.

I.S mch in1.S nguyn l:

Cc khi a) Khi bo v qu dng b) Khi Darlington c) Khi phn hi

2.S mch lp rp.

3.S mch pha sau

II.Tm hiu v mch 1. Vai tr tng khi.a) Khi bo v qu dng in: gm transistor T5, diode D5 v in tr

R6. Khi ny c tc dng gim dng in u ra khi n tng cao, bo v qu ti hay ngn mch cho mch. b) Khi Darlinton: bao gm 3 transistor mc kiu darlinton. Khi ny khuch i tn hiu iu khin a vo chn B ca T1. c) Khi phn hi u ra: gm transistor T4, cc in tr phn p cho T4, Rc ca T4, v diode zener. Khi ny c tc dng phn hi sai lch u ra v iu khin khi Darlinton. 2.Nguyn l hot ng. -Mch hot ng theo nguyn tc: iu chnh thay i in p ri trn CE ca transistor T3 ngc vi thay i ca in p ra, in p ra khng i. -Khi mch hot ng in p cc B ca T1 lun ln hn in p Zener, do vy cc transistor T1,2,3 lun thng, c in p ri trn CE ca T3. in p ra bng in p ngun tr i ip p ri ny. -Cc B ca T4 c phn p nh cc in tr R3, R4 v R5; do vy T4 thng. -Khi Ura tng, UB T4 tng, dn n UBE T4 tng, vic ny lm gim UCE T4, do vy UC T4 cng l UB T1 gim. UB T1 gim lm T1 v do c T2 v T3 u thng km, tc l UCE tng. in p ri trn CE ca T3 tng, vic ny lm gim in p ra. -Ngc li, khi in p ra gim, VBE T4 gim, lm VCE T4 tng, dn n VBT1 tng, lm T1, do T2, v T3 thng hn, dn n VCE T3 gim. in p ri trn CE ca T3 gim lm tng in p u ra. Nh vy bng vic thay i VCE ca T3 ngc vi thay i ca in p ra, in p ra c gi n nh. III.Tnh ton cc gi tr in tr: Cc in tr R3, R4 v R5 phn p cho cc B ca T4. T4 phi lm vic ch khuch i, do VBE ca T4 nh, trong khong 0,5-0,65. VE ca T4 bng VDZ bng 9V. VB T4 = 6,5- 6,65 V, Vra= 12V R4/(R4+R3)= 6.5/12= 0.542

Chn R3= 1k c R5= 1k v R4=2k in tr R1 cng tc ng ti u ra. Nhng hon ton c th chnh R3, v R4 v gi nguyn R1 c in p ra mong mun, tuy vy R1 khng c nh qu, cng khng c ln qu. C IC T4= . IBT4 v VB T1= VCC R1.IC T4, nu R1 qu ln hoc qu nh th s khng c gi tr no ca T4 VC T4 tha mn c. y em chn R1= 2k in p R2 ni tip vi DZ khng c tc dng nhiu, tuy vy nu ln qu s lm gim in p ca zener, nh qu s lm dng qua Zener qu ln. Em chn R2= 4k. IV.Cc gi tr linh kin s dng STT 1 . 2 . 3 . 4 . 5 . Tn linh kin in tr 1k Transistor C828 Transistor D468 TransistorH1061 in tr 0.33 S lng 10 1 1 1 1

Cc in tr 1k s c mc ni tip c c cc gi tr cn thit nh sau: R1 = R4 = 2k R2 = 4k R3 = R5 = 1k V.Cch o dng ng h vn nng v kim tra mchGii thiu v ng h vn nng ( VOM). ng h vn nng c 4 chc nng chnh l o in tr, in p AC/DC, v

dng in. u im ca ng vn nng l thy c s phng np ca t in, tuy nhin ng h ny c hn ch v chnh xc v c tr khng thp (khong 20K/Vol). -Vi thang o in tr ca ng h vn nng ta c th o c rt nhiu th. -o gi tr ca in tr -o thng mch -Kim tra s phng np ca t in -o tr khng -Kim tra diode v transistor

o in tr - thang ng h v cc thang o tr, nu in tr nh th thang x1 ohm hoc x10k, nu in tr ln th thang x1k hoc 10k. => sau chp hai que o v chnh chit o kim ng h bo v tr 0 ohm. -t que o vo hai u in tr, c tr s trn thang o, gi tr o c bng tch ca ch s thang o v thang o. -Nu ta thang o qu cao th kim ch ln mt cht , nh vy c tr s s khng chnh xc v ngc li

-Phi kim tra mch theo tng khi (tr khi bo v), khi cc khi hot ng tt th u ra l ng ch cn vi chnh.-Ta cng c th c c cc gi tr in tr qua mu sc cc vch

Hng dn o in p AC - o in p ta cng o tng t nh o in tr nhng phi chuyn v thang o in p VI.Kt qu: Sau mt s iu chnh cc in tr, cui cng em cng c c kt qu. Cc s liu o c: Thng s Mong mun o c Uvo (V) 15 20 Ura (V) 12 12 12 UCET3 (V) x x x UBET1T2T3 (V) 1.5-1.8 1.4 1.55 UDz UCET 4 UBET4 (V) (V) (V) 8.8-9.4 4.4-4.6 0.5-0.65 9.4 4.5 0.6 9.4 4.5 0.6

x: khng quan trng VII.Kt lun: - Mch n p tuyn tnh s dng cc linh kin c bn nh transistor, in trvv l mt mch kh n gin, nhng n gip ta hiu c c ch n p, cng nh nm c cch s dng transistor cho cc ng dng c th. -Khi thay i gi tr in p vo th in p ra lun lun t gi tr 12V. iu ny chng t mch chy n inhg v p ng ng yu cu ca mch n p.

Cui cng, em xin cm n cc c phng thc tp gip em lm c bi thc hnh ny.