Bi Tp TCS-UD 1

Trc NghimHy chn cu tr li ng cho cc sau :

1/. Trong kho st mch in t cng sut ni chung, tnh ton gi tr hiu dng dng in ngun lun lun c ngha.a/. ng b/. Sai

2/. Trong kho st mch in t cng sut ni chung, tnh ton gi tr trung bnh dng in ngun chc ngha khi ngun l :a/. Mt chiu b/. Xoay chiu

3/. Trong in t cng sut, khng c dng dng in no c cng tr s trung bnh v hiu dnga/. ng b/. Sai

4/. Trong tnh ton gn ng mch TCS lm vic vi ngun p, ngi ta thng ch tnh ton vi thnh phn Fourier tn s thp v thnh phn sng hi bc cao dng in lun thpa/. ng b/. Sai

5/. TRIAC thng khng c dng cho iu khin ng c trong cng nghip v :a/. N khng ch to c dng ln b/. N nhy vi nhiu v du/dt cho php nh

6/. Mt bt li ln ca vic dng GTO l dng kch ca n cn kh lna/. ng b/. Sai

7/. iu kin SCR dn l :a/. Gia Anode, Cathode c phn cc thun v c dng kch vo cc Gate ph hp. b/. Gia Anode, Cathode c phn cc thun hoc c dng kch vo cc Gate ph hp.

8/. Khi ct dng kch vo cc Gate ca SCR th lp tc SCR s tt.a/. ng b/. Sai

9/. Dng CB (ngt mch t ng Aptomat) bo vcho linh kin in t cng sut khi h hng khi ngn mch.a/. ng b/. Sai

10/. Trong mch hnh A :a/. D1 bo v qu p cho L1, C1 l t gia tc, R3 l in tr thot in tch.b/. D1 bo v qu p cho Q1, C1 l t gia tc, R3 l in tr thot in tch.

11/.Trong mch hnh A, vi cc tr s R1 = R2 = 2K s m bo Q1 dn bo ha. Cho dng qua cun dy L1 l100mA, Q1 c = 100.a/. ng b/. Sai

Cho b bin i p xoay chiu, ngun 220VAC/ 50 Hz, ti RL vi R = XL = 100 . 12/. p trn ti s cc i khi:a/. = 0o b/. = 90o c/. 45o d/. Cc cu a, b, c u sai

13/. V nguyn tc, mch pht xung iu khin pha s dng a/. Xung rng b/. Chui xung c/. C hai dng

14/. Nu ti l thun tr, nu gc iu khin = 90o th hiu dng p trn ti s l :a/. 110 (V) b/. 135 (V) c/. 155 (V) d/. Cc cu a, b, c u sai

Hnh A

Bi Tp TCS-UD 2

15/. Loi ng c no c tc thay i tuyn tnh theo in p (quan h gn ng) ?

a/. ng c DC b/. ng c KB

16/. Loi hm no c nng lng c tr v ngun ?

a/. Hm ng nng b/. Hm ti sinh

17/. Ph ti cnh qut hay my bm ly tm c c tnh c dng?a/. Tuyn tnh b/. Phi tuyn

18/. iu khin tc ng c DC, thng dng encoder hi tip tc nhng trong trng hp n gin, c th dng hi tip in p thay th encoder.

a/. ng b/. Sai

19/. Nguyn nhn khng th dng in p iu khin tc ng c KB l do momen suy gim nhanh khi gim in p.

a/. ng b/. Sai

20/. B ngun mt chiu khng th c chc nng va n p va n dng.

a/. ng b/. Sai

21/. Khu tch phn I trong b iu khin PID c dng tng thi gian p ng ca h thng.

a/. ng b/. Sai

22/. iu ch rng xung PWM trong bin tn c dng :a/. iu khin tn s b/. iu khin in p

23/. Trong h linh kin thyristor c loi l ngt ngt in mt chiu

a/. ng b/. Sai

24/. Mt nguyn nhn gy nhiu trong li in l s t bin dng in

a/. ng b/. Sai

25/. Khng th dng b chnh lu iu khin pha np in nng vo li.

a/. ng b/. Sai

26/. iu kin cn v cu H truyn nng lng hai chiu l c cc diod phc hi nhanh song song ngc vi ngt in mt chiu

a/. ng b/. Sai

27/. S hiu chnh no lun c dng trong cc b bin i hay iu khin tc ng c :

a/. PI b/. PID

28/. SCR c th b t kch do :a/. Tc tng p trn Anode qu ln b/. Tc tng dng qua Anode qu ln

29/. tt SCR :a/. Ct dng kch vo cc Gate b/. Cng bc dng Anode v zero

Bi Tp TCS-UD 3

30/. Cho mch chnh lu SCR hnh tia trong mng in cng nghip 3 pha 220/380 VAC,50 Hz. in p ngc max t ln mi SCR l :

a/. 220 2 VAC b/. 380 2 VAC

31/. Cho mch chnh lu dng SCR hnh cu 3 pha trong mng in cng nghip 220/380 VAC, 50 Hz. Dng in trung bnh qua mi SCR bng :a/. 1/3 dng ti b/. 1/6 dng ti

32/. Khi thit k bin tn iu chnh tc ng c AC, nu gim tn s f m khng gim in p U ca ng ra bin tn th :a/. Tc ca ng c s khng gim b/. Dng in trong ng c s tng cao gy ra pht nng

33/. ng c quay u vi tc khng i khi :a/. in p t vo ng c khng ib/. Momen ng c lun lun bng momen cnc/. C hai cu u sai

34/. Nu momen khi ng ca ng c nh hn momen cn th ng c s khng tng tc c v s gy ra pht nng c th dn n chy ng c.a/. ng b/. Sai

35/. Tc ng c mt chiu t l tuyn tnh vi t thng kch thcha/. ng b/. Sai

36/. gi n nh tc ng c mt chiu, c th :a/. hi tip dng in phn ng b/. hi tip in p phn ngc/. hi tip c hai dng, p d/. hi tip mt trong hai dng/p

37/. IGBT c c tnh:

a/. iu khin ging nh MosFET

b/. Tng t nh MosFET vi dng lm vic ln hn

c/. C kh nng tn nhit tt hn

d/. Thng ch to vi p lm vic thp

Cho mch iu khin pha 1 SCR sau vi ngun hnh sin hiu dng 200 V, ti R bng 10 ohm:

38/. Mch trn thng s dng cho:

a/. Ti R (bng n, m hn in..) cng sut nh

b/. Ti cun dy c L ln

39/. Khi gc iu khin pha = 90o, hiu dng p trn ti bng:

a/. 100 V b/. 50 V c/. 45 V d/. 50 2 V

40/. Khi gc iu khin pha = 90o v L = , t s dng trung bnh qua diod so vi dng trung bnhqua SCR :

a/. Gp 2 ln b/. Gp 3 ln c/. Hai cu u sai

Ru D

L

T

i

Bi Tp TCS-UD 4

41/. Ta c th chn nh mc p ca SCR, diod:

a/. Ln hn 200 V b/. Ln hn 200 2 V c/. Ph thuc datasheet ca linh kin

T Lun

1/. Hy gii thch vai tr ca cc R, C trong qu trnh ng ngt ca BJT Q trong mch in hnh 1

2/. Cho mch in hnh 2 vi R1 = R2 = 10 , ngun u1 cdng xung vung (hnh 3) vi V = 20 VDC. Tnh p trung bnhtrn ti R2 v cng sut tiu th ca in tr ny

3/. Cng vi mch hnh 2 & 3. Nu mc song song vi R2 t in c in dung C = 500 uF, tr trung bnh in p trn R2 v cng sut tiu th ca n c thay i khng ? Nu tr li c, gii thch ngn l do.

4/. Tnh cng sut tiu th ca bng n 220V/40W khi ta ni tip vi n mt diode.

5/. Cho b iu khin p xoay chiu, s 1 pha dng TRIAC, ti R = 10 , L = 10 mH. Bit gc

iu khin pha 090 , gc dn ca TRIAC l 0120 . V dng sng dng in qua ti, dng sng in p trn TRIAC. Tnh tr hiu dng p trn ti, bit p ngun 220VAC, 50Hz.

6/. Cho b chnh lu iu khin pha 4 SCR, s cu 1 pha vi ngun 200V (hiu dng), 50 Hz, c ti RL vi R = XL = 10 . Tnh gc iu khin ln nht dng ti cn lin tc, v dng sng dng, p trn ti gc gii hn ny.

7/. Cho s chnh lu 3 pha hnh tia ti thun tr. V dng sng in p ra vi gc iu khin 060 , v dng sng xung kch tng ng cc SCR.

8/. Cho s chnh lu 1 SCR iu khin pha vi 090 , lm vic vi p ngun 100VAC (gi trhiu dng). Gi s st p thun trn SCR bng 0. V v tnh tr trung bnh p ra trong hai trng hp. a/. Ti thun tr R = 100b/. Ti R = 10 ni tip E = 40VDC

9/. Cho s chnh lu 3 pha hnh tia iu khin pha ti RLE vi L ln dng ti lin tc v phng. a/. V v ch thch y dng xung kch cc SCR, dng p ng ra, dng p t vo SCR pha B khi

gc iu khin pha 090 b/. Tnh dng trung bnh qua ti, dng trung bnh qua cc SCR v cng sut biu kin u vo b

chnh lu khi gc iu khin 060 . Cho bit R = 10, E = 100V v p ngun 220/380V.

u

R1R2

1

V

u

0 3 10

1

t (ms)

Hnh 1

Hnh 3Hnh 2

Bi Tp TCS-UD 5

10/. Mt accu c dng np quy nh l dng mt chiu phng 1A. Nu ta np accu bng mch TCS cho ra dng i(t) nh hnh bn c tr trung bnh l 1A, tn hao in tr trong ca accu khi np in tng hay gim ? Hy tnh lng tng (hay gim) ny l bao nhiu % ?

11/. Cho mch li BJT cng sut Q3 c 20 , dng ti qua cc C ca Q3 bng 3A. Tn

hiu iu khin ng nhp l 5V/0.5mA. Hy tnh chn cc in tr v h s khuch i dng ca cp darlington Q1Q2.

12/. Cho s chnh lu 3 pha hnh tia (hnh A), p ngun bng 200VAC (p dy). V dng xung

iu khin cc SCR v p ra vi ti RL ng vi gc iu khin 060 . Tnh tr trung bnh p ngra vi gi s dng ti lin tc.

13/. Cng vi cu trn, nu ta gn ng ra mt diode phng in nh hnh B, dng p trn ti thay i nh th no ? Tnh tr trung bnh p ng ra lc ny ? Vi R = 10 , L ln dng ti phng lin tc, tnh tr trung bnh dng qua diode phng in ?

14/. Cho mch nh hnh v. Cho bit y l mch g ? Nu mt ng dng thc t ca mch. Trnh by nguyn l hot ng v chc nng ca tng linh kin trong mch.

T

I

t

T

i(t)

Q1

27

mA

0.454 mA Q2

22

0

Q3

5V

22

0.1

mA

0.354 mA

18K

In (5V)

17

7 m

A

6K8 3 A

150 mA

uo

A

B

T3

T2

C

N

T1

A

B

C

n

Chnh lu au vao Nghch lu Mach moi

+

_

T2T1 T3

T4 T5 T6

L

T13

T11

T12

T14

Lp

C

R

Tp

Rp

L

Cp

Hnh BHnh A