Thuchanh Ad Ac

TRNG CAO NG CNG NGHIP 4KHOA IN T T NG HA

THC HNH

PHN TCH MCH DC-ACH CAO NG IN T

Bin son ThS NGUYN CHNG NH

Lu hnh ni b 2004

THC HNH PHN TCH MCH DC AC

3

LI NI UPhn tch mch DC AC l mn hc c s nhm cung cp cho cc sinh vin ngnh in - in t phng php phn tch tng hp mch l c s thit k h thng in - in t. Nhm gip sinh vin hiu r thm v l thuyt, gio trnh thc hnh Phn tch mch DC AC hng dn cho sinh vin s dng phm mm m phng gii mch v kim chng cc nh lut hc. Trong chng trnh s dng phn mm Electronic Workbench 5.12 m phng mch in do tnh cht trc quan v d s dng. Sinh vin nn m phng tt c cc bi tp c trong tp sch ny v cc bi tp trong gio trnh l thuyt c th nm vng v phn tch mch in. Gio trnh gm 30 tit, chia lm 6 bi Bi 1. Chng trnh Electronic Workbench Bi 2. Nguyn l xp chng Bi 3. Mch tng ng Thevenin v Norton Bi 4. Xc nh cc thng s ca mng hai ca Bi 5. Kho st mch lc th ng R L C Bi 6. Kim tra Mong rng cc sinh vin vin t nhiu kt qu sau qu trnh thc hnh TP.HCM nm 2004 ThS Nguyn Chng nh

PHN TCH MCH DC AC BI 1

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CHNG TRNH ELECTRONIC WORKBENCH1.1. GII THIU Electronic Workbench l phn mm m phng mch in, o c cc mch s v tng t ca Hng INTERACTIVE IMAGE TECHNOLOGIES. y l mt phn mm tr gip thit k cc mch s v tng t rt hon chnh, cho php ta thit k ri th vi nhiu ngun tn hiu: ngun sin, xung, V nhiu thit b m phng nh oscilloscope, VOM, Bode Plotter, Logic Probe 1.2. HNG DN S DNG CHNG TRNH 1.2.1 Chy chng trnh Khi ng chng trnh Electronics Workbench bng cch chn Start ( Program Electronics Workbench Electronics Workbench . Sau ca s mn hnh thit k ca chng trnh xut hin vi y cc menu, thanh cng c h tr cho vic thit k v m phng mch in

Cc hp cha linh kin Nt cng tc thc hin m phng

VNG V S MCH IN

Hnh 1.1

6 1.2.2. Cc bc m phng mch in lp v th mt mch in, phi tin hnh cc bc sau: 1. Ly linh kin t vng cha linh kin 2. t linh kin cn ly vo ng v tr trong vng lm vic 3. t cc gi tr linh kin 4. Ni cc linh kin 5. Ly cc dng c o cn thit v ni vo nhng im cn o 6. Bt cng tc mch hot ng 1.3. THC HNH

THC HNH

Trong phn thc hnh chng ta s lp rp v o th mt mch n gin nh sau

Hnh 1.2 Tin hnh lp rp v th mch theo cc bc shau Bc 1. Khi ng chng trnh Electronics Workbench bng cch chn Start ( Program Electronics Workbench Electronics Workbench Bc 2. Chn v ly cc linh kin vo mn hnh lm vic. Ly in tr: Nhp chn hp cng c Basic cha cc linh kin thng thng nh in tr t in, cun dy

Hnh 1.3 Nhp chn linh kin in tr nhp chut v ko n vo mn hnh thit k. Lu phi nhn v gi phm tri chut ko n v tr cn t ri th ra. xoay linh kin, phi chn n sau nhn Ctrl + R. Sau khi ly ht cc linh kin ta c s sp xp nh hnh sau

PHN TCH MCH DC AC

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Hnh 1.4 Bc 3. Thay i gi tr ca linh kin. thay i gi tr ca linh kin nhp p vo n. Nhp p vo in tr, hp thoi Resistor Properties xut hin, nhp chn th Value nu n cha c chn. Nhp vo gi tr mi cho in tr trong khung Resistance (R) v chn n v trong hp danh sch k bn. Nhn OK hon tt.

Hnh 1.5 Chn th Label nhp k hiu cho linh kin v d R1, R2,

Hnh 1.6 Bc 4. Tin hnh ni dy cho cc linh kin

8

THC HNH

Hnh 1.7 Bc 5. Gn cc thit b o vo mch tng t nh phn gn linh kin. bi tp ny chng ta cn o dng, p do dng thit b Multimeter trong hp Instruments

Hnh 1.8 Gn thit b o vo mch, lu o in p mc Multimeter song song vi mch cn o v o dng in mc Multimeter ni tip vi mch

Hnh 1.9

Bc 6. Bt cng tc chy m phng. Ta c c gi tr ca in p trn R2 nh hnh 1.9.

Hnh 1.10 o dng in trong mch bng cch mc ni tip Multimeter vo mch, v chuyn Multimeter v thang o dng (A). Kt qu nh hnh 1.10. Tip tc o in p trn in tr R1. Cui cng so snh kt qu vi l thuyt.

PHN TCH MCH DC AC 1.4. CC K HIU LINH KIN TRONG ELECTRONIC WORKBENCH 1.4.1. Ngun ph thuc a. Ngun p ph thuc p (Voltage-Controlled Voltage Source)

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b. Ngun p ph thuc dng (Current Controlled Voltage Source)

c. Ngun dng ph thuc p (Voltage-Controlled Current Source)

d. Ngun dng ph thuc dng (Current Controlled Current Source) 1.4.2. Cc thit b o a. ng h o vn nng Multimeter dng o in p, dng in, in tr hay suy hao gia hai im ca mt mch. Tu i lng cn o l dng, p, in tr hay decibel m ta chn chc nng tng ng trn Multimeter. Ta cng c th chn tn hiu cn o l AC hay DC bng cc nhn nt tng ng (AC: ~ hay DC: ) b.Ngun pht sng (function generator) Ngun pht sng to ra cc dng sng sin, vung, tam gic. Ta c c th iu chnh c tn s, duty cycle, bin v mc DC ca tn hiu.

c. Oscilloscope Oscilloscope c m phng ging nh mt oscilloscope thc c hai knh.

10

THC HNH

e. Bode Plotter Bode Plotter dng v biu Bode, thng l v p ng tn s ca cc mch lc, mch khuc i

1.5. BI TP T THC HNH 1.5.1 Tm I1 v I26 32

S:

I1 = 5A I2 = -3A50V

I1

4 15

12 6 2 I2 Rab 30

40

1.5.2. Tnh dng I trong hai trng hp a. Rab = Rbc = Rca = 3 b. Rab = Rca = 30 v Rbc = 40 2Rbc

Rca

57V

I

5

PHN TCH MCH DC AC 1.5.3. Tm dng in trong cc nhnh nh hnh sau I110

11

40

I20.4V 0.03A 20 1V

I3 S: I1 = 0.02A, I2 = 0.02A, I3 = 0.01A 1.5.4 Tm U6 + 5V U1 4 2 + 24 6 U

U1 3

S: U = -3V 1.5.5 Tm p U02U0 2

S: U0 = 4V

6

1

+ U0

4A

1.5.6 Tm in p U0

3 + 6A Uo 4 Ix 12 R1 4 12 4Ix

S: U0 = 6V


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NGUYN L XP CHNG2.1. MC CH Dng phn mm Electronic Workbench kim chng nguyn l xp chng ca mch in. 2.2. NI DUNG Trong mt mch c nhiu ngun c lp, p ng (dng, p) do nhiu ngun gy ra bng tng cc p ng do tng ngun gy ra khi cho cc ngun khc bng 0 Ngun p = 0 : ngn mch Ngun dng = 0: h mch Nh vy, mt mch bt k c N ngun kch thch c lp. Mt p ng Xk s c tnhXk = Xii =1

N

(3.8)

X i p ng ca mch khi kch thch l Fi cc kch thch khc cho bng 0

p ng to bi nhiu ngun kch thch tc ng ng thi th bng tng cc p ng to bi mi ngun kch thch tc ng ring r. 2.3. THC HNH Cho mch nh hnh 3.1. Tm I bng phng php xp chng4 I 6A 2 18V

Hnh 2.1

Bc 1: Mc mch nh hnh, dng Multimeter o dng I

Hnh 2.2

14 Kt qu I= Bc 2. Xt trng hp ngun 18 V, cho ngun 6A = 0

THC HNH

Hnh 2.3 Kt qu I1 = Bc 3. Xt trng hp ngun 6A, cho ngun 18V = 0

Hnh 2.4 Kt qu I2 = Bc 4. Kim chng nguyn l xp chng So snh I v I1 + I2 3.4. CC BI TP T THC HNH 3.4.1. Cho mch nh hnh 3.5. Tm V bng phng php xp chngI1 1

+ V 1 12V 2I1 6A

Hnh 3.5

PHN TCH MCH DC AC 3.4.2. Tm cc dng I1, I2, I3, I4, bng phng php xp chngI1 2 1A I2 3 5V 2 I4 3 I3

15

Hnh 3.6


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MCH TNG NG THEVENIN V NORTON3.1. MC CH Dng phn mm Electronic Workbench xc nh s tng ng Thevenin Norton ca mch in. 3.2. NI DUNG nh l Thevenin: Mt mng mt ca bt k c th thay th tng ng bi mt mch gm c mt ngun p c gi tr bng in p h mch mc ni tip vi mt tr khng ZT ZTA

Mch in

A

B

= hmB

Hnh 3.1 Mch tng ng Thevenvin nh l Norton: Mt mng mt ca bt k c th thay th tng ng bi mt mch gm c mt ngun dng c gi tr bng dng in trn ca khi ngn mch mc ni tip vi mt tr khng ZTA

Mch in

A

B

J = nm

ZTB

Hnh 3.2. Mch tng ng Norton Tr khng ZT chnh l tr khng nhn vo hai cc ca mng mt ca khi cho cc ngun c lp bng 0. Ngun p = 0 : ngn mch Ngun dng = 0: h mch tnh tr khng ZT ta c th dng cc cch sau Cch 1: Trit tiu tt c cc ngun c lp trong mng mt ca A

18 t AMng mt ca (Trit tiu tt c cc ngun c lp) Mng mt ca (Trit tiu tt c cc ngun c lp)

THC HNH A+ t B Ut ZT =

t B Et ZT =

Jt

(a)

Hnh 3.3 I t

(b)

Jt

Kch thch ca A, B mt ngun p nh hnh 3.18a (gi tr t c th chn tu , v d t = 1V). Xc nh dng t chy vo mch t ngun t. Suy ra ZT =

Et It

.

Cng c th kch thch ca A, B mt ngun dng J t nh hnh 3.18b (gi tr J t c th chn tu , v d J t = 1A). Xc nh in p t, t suy ra ZT =

Ut Jt

.

Cch 2: Ln lt h mch v ngn mch hai cc A, B xc nh in p hm v dng in nm. T suy ra ZT =U hm I nm

Cch 3. Trng hp mch khng cha ngun ph thuc no ta tnh ZT bng cc trit tiu tt c cc ngun c lp trong mch, sau tnh ZT nhn vo hai cc A, B bng cc php bin i tng ng 3.3. THC HNH Cho mch nh hnh v, kim chng s tng ng Thevenin v Norton6 12V A I 1 RL 3 1A 2 2A B

Hnh 3.4

Bc 1. Mc mch o UAB v dng IL, lu o p ta mc my o song song vi ti v o dng ta mc my o ni tip vi ti

PHN TCH MCH DC AC

19

Hnh 3.5

Hnh 3.6 Kt qu UAB = IL = Bc 2. H mch RL o Uhm

Hnh 3.7 Kt qu Uhm = Bc 3. Ngn mch RL o Inm

Hnh 3.8 Kt qu Inm =

20

THC HNH

Bc 4. Cho tt cc ngun c lp bng 0 (ngn mch ngun p h mch ngun dng), dng multimeter thang o o ZT

Hnh 3.9 Kt qu ZT = Bc 5. Kim chng mch tng ng Thevenin Xy dng mch tng tng Thevenin v gn thm in tr ti, dng Multimeter o dng v p trn ti. ZT Uhm RL

Kt qu UAB = IL = So snh vi gi tr o bc 1

Hnh 3.10

Bc 6. Kim chng mch tng ng Norton Xy dng mch tng tng Thevenin v gn thm in tr ti, dng Multimeter o dng v p trn ti.

J = Ihm

ZT

RL

Hnh 3.11 Kt qu UAB = IL = So snh vi gi tr o bc 1 Bc 7. Nhn xt quan h gia Uhm,Inm v ZT

PHN TCH MCH DC AC 3.4. BI TP T THC HNH 3.4.1 Tm mch tng ng Thevenin ca mch hnh 3.121 A 18A 2 B Hnh 3.12 12 18V 6

21

S: E = 10V, R0 = 3

3.4.2. Tnh R cng sut tiu th trn n l cc i. Tm cng sut 4 12

8V

1A

R

3

6V

S: R = 1, P = 900W 3.4.3. Tm mch tng ng Thevenin v Norton ca mch sau40 10 2 + 10V 30 v1 6 3v1 B Hnh 3.14 12 A

Hnh 3.13


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XC NH CC THNG S MNG HAI CA4.1. MC CH Dng phn mm Electronic Workbench xc nh cc thng s ca ca mng hai ca. 4.2. NI DUNG Cc ma trn ca mng hai ca c nh ngha da trn cc quan h bi cc cp bin trng thi 1, 1 v 2, 2 vi chiu dng in v in p quy c nh hnh 4.1 2 2 1 +1

Mng hai ca

2

+

1 Ca 1

2 Ca 2

Hnh 4.1 4.2.1 Ma trn Z Biu din 1 v 2 theo 1 V 2 1 = Z111 + Z122 2 = Z211 + Z222 4.2.2 Ma trn Y Biu din 1v 2 theo 1 V 2 1 =Y111+Y122 2 =Y211+Y222 4.2.3 Ma trn H Biu din 1 v 1 theo 1 v 1 1 = H111 + H122 2 = H211 + H222 4.2.4 Ma trn G Biu din 1 v 1 theo 1 v 2 (4.3) (4.2) (4.1)

24 1 = G111+G122 2 = G211+G222

THC HNH (4.4)

4.2.5 Ma trn A

Biu din 1 v 1 theo 2 v 2 1=A112 A122 1=A212 A222 4.2.6 Ma trn B Biu din 2 v 2 theo 1 v 1 2 = B111 B121 2 = B211 B221 4.3. THC HNH Xc nh cc thng s ma trn A ca mng hai ca hnh 5.3 Ta c phng trnh ma trn A 1 = A112 A122 1 = A212 A222 Ngn mch ca 2 (2 = 0) hnh 5.4A 12 = U1

(4.5)

(4.6)

2 4

4

Hnh 4.2 1 2 4 4 2

I2 U 2 = 0

v A 22 =

I1

1

I2 U2 = 0 1 + 1 Hnh 4.3 2 4 2 = 0 + 4 2

H mch ca 2 (2 = 0) hnh 5.5A 11 = U1

U2 I2 = 0

A 21 =

I1

U2 I2 = 0

Hnh 4.4

Bc 1 Ngn mch ca 2, cho ngun U1 = 10V (c th l gi tr khc), tin hnh o I1 v I2 nh hnh 4.5

PHN TCH MCH DC AC

25

Hnh 4.5 Kt qu I1 = I2 = Suy ra A12 v A22 Bc 2. H mch ca 2, cho ngun U1 = 10V (c th l gi tr khc), tin hnh o I1 v U2 nh hnh 4.6

Hnh 4.6 Kt qu I1 = U2 = Suy ra A11 v A21 Bc 3: So snh kt qu vi l thuyt 4.4. BI TP T THC HNH Tin hnh cc xc nh cc ma trn Z, Y, G, H, v B ca mng hai ca phn 4.2.


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KHO ST MCH LC TH NG R, L, C5.1. MC CH Dng phn mm Electronic Workbench kho st p tuyn tn s trn cc mch c bn R L v R C, t ng dng vo vic m phng cc mch lc 5.2. NI DUNG Trong cc mch lc R L, do tnh cht cun cm dng in chm pha hn cun cm mt gc 900, v in khng cun dy ph thuc theo tn s XL = L. Do tn s cng cao, tr khng cun dy cng ln v v vy, tu theo cch u cun dy trong mch, ta s c nhng mch in c tnh cht chn lc tn s thch hp, ta gi l mch lc. Nh trong mch lc thng cao dng R L, ta c tn s ct ca mch lc xc nh bi:

1R 2L Mt cch tng t, t in c tnhcht i lp vi cun cm, cng c dng trong mch lc R C. Nh trong cc mch lc thng thp dng RC, ta c tn s ct ca mch lc xc nh bi: 1R fc = 2C fc =5.3. THC HNH 5.3.1. Mch lc thng cao R L Cho mch R L nh sau100

10 mH

Hnh 5.1

Bc 1. Dng my pht sng, cho bin 2V, tn s 1KHz, to ngun kch thch cho mch. Dng dao ng k v dng tn hiu vo mch v tn hiu ra trn cun dy. Nhn xt di pha ca hai tn hiu ny

28

THC HNH

Hnh 5.2 Bc 2. Dng Volt k o in p trn ngun vo v trn cc phn t mch. Xy dng gin vector ca mch.

Hnh 5.3 Bc 3. Dng my v gin Bode, xc nh tn s ct ca mch lc. Tnh ton gi tr ny bng cng thc v so snh kt qu.

Hnh 5.4 5.3.2. Mch lc thng thp R C Cho mch lc thng thp R C nh sau

Hnh 5.5 Bc 1. Dng my pht sng, cho bin 2V, tn s 1KHz, to ngun kch thch cho mch. Dng dao ng k v dng tn hiu vo mch v tn hiu ra trn cun dy. Nhn xt di pha ca hai tn hiu ny

PHN TCH MCH DC AC

29

Hnh 5.6 Bc 2. Dng Volt k o in p trn ngun vo v trn cc phn t mch. Xy dng gin vector ca mch.

Hnh 5.7 Bc 3. Dng my v gin Bode, xc nh tn s ct ca mch lc. Tnh ton gi tr ny bng cng thc v so snh kt qu.

Hnh 5.8 5.4. BI TP T THC HNH Tng t nh trn kho st mch lc thng thp R L, mch lc thng cao RC, v mch lc R L C.

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