bt mach dien

7/27/2019 BT Mach Dien

1/60

BI TP MCH IN

NH XUT BN KHOA HC V KTHUT

H NI - 2010


2/60

1

BAI TAP CHNG 1

1.1Cho mach ien H.1.1) .Tnh dong I1 11, I2 I3

- Vong 1:

.

Giai:Ap dung nh luat Kirchhoff ve ien the: H.1.1

( )

( ) ( )

1 2

2 3

1 2 3

2 1

2 3

2 1 2

2 1

1 1

1

1

12 6 4 (1)

6 4 2 (2)

(3)

3(1) 3 (4)2

(2) 4 6 2 (5)

(3) & (5) : 4 6 2

6 6 2 (6)

3(6) & (4) : 6 3 6 2

2

9 2 18 6 24

242,1811

V I I

V I I

I I I

I V I

I V I

I V I I

I V I

V I V I

I

I A

=

= +

+ =

=

=

= +

=

=

+ = + =

= =

Thay I1

( )2

2

3 1 2

3 6, 463 2,18 3 3 3, 27 0, 27

2 2

0,27

2,18 0, 27 2, 45

I V A

I A

I I I A A A

= = = =

=

= + = + =

vao (4) cho:

+V1

12V

R16

R32

R24

+V26V

I 1 I 3

I 2


3/60

2

Cach khac:Ap dung nguyen ly chong chat,

- Noi tat V2

c:

( )( ) ( )'1

4 2 4812 2,18

224 2 6aa

V

V V V= = =+

- Noi tat V1 c:

' '1 '2 2,18 3, 27 1, 09

aa tot aa aaV V V V V V = + = =

Tr so cac dong ien:

( )

( )

2

2

1 '

1

3

1, 090,272

4

12 0,1, 09 13,092,18

1 6 6

1, 09 6 4,912,445

2 2

aa

aa

V VI A

R

VV V VI V

R

V VI V

= = =

= = = =

= = =

Do dong ien I2co tr am , nen chieu thc I2

la chieu ngc lai.

ap so:I1= 1, 877AI2= -0,187AI3 1.3.Tnh tr so V

= 1,690A H.1.2

O

1.4Cho mch in H.1.4 Tnh dong ien chay qua tai.

h.1.3 bang:1. phng phap nut2. Nguyen ly chong chapap so:Vo = 8,57V H. 1.3

+ V112V

Req=R2/ / R3

R16

a'

R24

a

R32

( )( )

( )'24 6 14,4

6 3, 274, 44 6 2

aa

VV V V= = =

+

+V26V

R' eq=R2/ / R1

R16

a'

R24

a

R32

1.2Cho mach ien theo H.1.2.Tnh dong I 1, I 2, I3.

-

vo

++

-

I

6A

+

-

8V

V1

R1

2

R2

4

R3

2

R4

6

+V1

12V


4/60

3

H.1.4Giai:

Ta lan lt co: ngo aa : Sau khi cho h tai va ap dung nh ly Thevenin ngo aa :

ngo bb :

ngo ra cc :

Vay mach ien tng ng Thevenin cuoi cung cho:

+E

72V

aR12k

a'

R22k

bR31k

b'

R42k

cR51k

c'

R62k

dR6500

d'

RL1k

+VTHa

36V

RTHa

1k

bR3

1k

b'

R42k

cR51k

c'

R62k

dR6500

+VTHb

18V

RTHb

1k

cR5

1k

c'

R62k

dR6

500

+VTHc

9V

cRTHc

1k

dR6

500


5/60

4

( )9 9

1 0, 5 1 2, 5

3,6

THc

THc L

VI

R R

V V

k k

mA

=+

= =+ +

=

1.5 Tnh mach tng ng Thevenincua mach ien cho H. 1.5.

ap so: H.1.5VTH= 0,125VRTH = 1

-

vo

++

-

I

1A

R4

1

R5

2

R6

1

R6

2

R32

R2

1

R11

I+VTHc

9V

cRTHc

1k

dR6

500

d'

RL

1kI


6/60

1

Bi tpCh.2

2.1 Cho mch theo H.2.1 vi diod c Is= 1 pA, VT

1.I

= 0,025V.Tnh:

2.D

D di v =

3.

rd

Gii:

1. Tnh I

.

D

( ) ( ) ( )12 12 121 10 1 10 1,45.101,45

D T D TV V V V

D SI I e e

A

= = =

=

:H . 2 . 1

2. Tnhd

i

Tuyn tnh ho trong ch tn hiu nh cho:

( ) ( )

( )

1D T D T

D T

D D D

V V v V S

S D

T

v VS

D D

T

i I i

II e e v

V

Ii e v

V

= +

= +

=

Mt khc, ngun tc ng AC cho bi:

( )0,7 0,001sinI I Iv V v V t V = + = + Nn cho:

( )0,7 0,001sinD D Dv V v V t V = + = + Tnh c:

( )12

0 ,7 0 ,02 5100,001sin

0.025

1, 450,001sin 0,058sin

0,025

D TV V V VSD D

T

I Ai e v e t

V V

t t

= =

= =

3.Tnh rd

1

0,0250,017

1, 45

D Tv VsD Dd

d D T T

TD

D

Idi Ig er dv V V

V Vr

I A

= = =

= = =

C li:( )

( )

0,001sin0,059sin

0,017

DD

d

t Vvi t A

r

= = =

-

+

-=0.001sinwt

vi

iD

+

D

+

=0,7V

VB


7/60

2

2.2.Cho mch H.2.2R1 = R2 = R4 = 1 k ,R3 = 0,5 k . Diod D1

dng in cho bi:c

( )1D Tv VD Si I e=

vi dng bo hoIS= 1.10

-9A vin th nhit

VT

2. Gi s m hnh l tng diod c phn cc bi ngun in0,6V . Tnh v

= 25 mV1. Tnh mch tng ng Thevenin ca H .2 . 2

mch ni vi diod.

Dv iD khi VI3. Tnh in tr diod chung quanh im tnh Q (xc nh cu 3)

trong m hnh tuyn tnh ca diod ch tn hiu nh.

= 4V.

4. Dng m hnh phn c, tnh vd(t) nu c

vI ( )t= 4V + 0,004 V cos V.Gii:

1. Mch in tng ng Thevenin:

( )

( )

1 1

0,5 0,5 1 4

1 1 0,5 1 0,5

ITH I

TH

kV V V

k k k

R k k k k k

=

= + +

= + =

2. Tnh th v dng :Vaa = () VI= 4/4 = 1V

+

-

vI

R1

1k

R2

1k

R3

0.5k

D1 R4

1k

+

-

VI

a'

a

R1

1k

R2

1k

R3

0.5k

R4

1k

RTH

a'

a

1k

0.5k+0.5k1k 1k

0.5k1k

R2

1k

R1

1k

+

VI

b'

b a

1k

0.5k0.5k

+VI/2


8/60

3

0,6

1 0,60,8

0,5

D

D

v V

V Vi mA

k

=

= =

3. M hnh tuyn tnh ca diod c gi trvi hot ng tn

hiu nhchung quanh im tnh Q xc nh cu 2:4

9,44.10D TV VD T

d

D S

dv Vr e

di I

= = = 3. Tnh vd

(t)

( )

4

3

7 9

9,44.100,004cos

0,5.10

18,88.10 0, 004 7, 552.10 cos

d

d i

d TH

rv v t

r R

t

= +

= =

97,55.10 cos

dv t

=

2.3. Cho mch H.2.3. c cha phn t phi tuyn vi c tnhsau:

4 210 0

0 0

N N

N

N

v khi vi

khi v

>

= 0.Tnh vC

( ) ( )( )1 1 2

1

t

c f f i

t

t

v t v v v e

e

e

=

=

= +

t).Giai :Ta co ien the hai au tu cho :

H 8 3

8.4 . Cho mach ao INV1 thuc INV2 H.8.4a. . Mach tng ng c ve H.8.4.b .Cac iem A,B,C bieu dien gia tr logic vA,vB, vC 1. Viet bieu thc thi gian len t .rvathi gian xuong tf cua mach bieu dien H.8.4.a . Gia s Cac mach ao tuan theoqui tac tnh vi ien the ngngVIL= VOL= VL. va VIH= VOH= VH.Lu y: Thi gian len cua INV1 la thi gianvBcan co e chuyen trang thai t ien thethap nhat vBat c cho bi cau chia theRLva RON. Tng t, thi gian xuong cua lathi gian vB the ln nhat la vcan e chuyen trang thai t ienB) e vIt 0V en bcchuyen len Vs tai ngo vao vA. H.8.4a2. Tnh tr so thi gian tre tpdcua INV1

+

-

a

vs

3V-

R1

1k

+R2

2kvcC

10uF

+

-

a

vs

1V-

R

vcC

+

K

t=0

Vc

+

VsVs

-

vB

+

-

vA

+

-

RL

RL

CBINV2

A INV1


36/60

3

trong mach H. 8.4a v RON = 1 k ,RL= 10RON, CGS= 1 nF, Vs= 5V,VL= 1V va VH Mach tng ng :

1.MOSFET dan cho :

=3V?Giai :

ON

OL S

L ON

RV V

R R=

+

Khi MOSFET ngng cho :

OH SV V=

Lan lt t nh c :

( ) ln S Hr L GS ON

S S

ON L

ONL S

ON ON Lf GS

S HON L

ONS S

ON L

V Vt R C

RV V

R R

RV VR R R

t CV VR R

RV V

R R

=

= +

2. tpd s= 8,2

vIN < vTH

vIN

vIN

vIN>VT

Vs

vo

Vo

Vs

CGS CGS

RL

RON

RL


37/60

1

BAI TP Ch. 9 Mach loc

9.1 Tnh bien o va pha cua cac bieu thc sau:( )( )( )( )

( )( )( )( )( )( )

( )( )( ) ( )( ) ( )

0

0

30 39

25 0

20 23

20 27

30 15 1,5 1 30

1. 8 7 5 0, 3 0,1

8, 5 34 20 60 cos10 sin102.

25 37

3. 25 10 14 13 1 2

4. 13 6

o

o

o o

o o

o

j j

j o

j j

j j

j j j

j e e j

j e j

e e

e e j j

e e

+

+

+ +

ap so:1. Bien o = 16,8

Pha = 13,754

2. Bien o = 45,47o

Pha = 18

3. Bien o = 2136o

Pha = 78

4.

Bien o = 47,3

o

Pha = -15

9.2 Viet bieu thc H jw) = Vo/Vi, bien oo

( )H j va pha ( )H j theo trongbon trng hp sau:

a) b) c) d)ap so

+

-2ejwvi

voL

i(t) +

-

R

+

-ejwt

vivoC

+

R

+

-=10ejw

vi vo

L 1H

i(t) +

-

R10

+

-=5ejwt

vi

=1uFC

+R

1M

i(t)

vo

-


38/60

2

9.3 Cho mach theo H.9.3 vi R = 1k , C1 = 20 F , C2 = 20 F .1. Tnh bien o va pha cua H w) = Vo/Vi2. Cho v .iien the ra trang thai dng sin, vt) = cos 100t) + cos 1000t), tmo

( ) ( ) ( )

2

2

1 11. ,

21

100

arctan100

1 12. cos 100 45 cos 10000 89,4

200.012 2

jo

i

o o

o

Ve

V

v t t t

=

+

=

= +

t).ap so

9.4. Viet bieu thc cua tng mach ien sau ay :

ap so

( )( )

( )

( )

( )

2

2 2

2 2

2 2

11. , arctan

1

2. , arctan

13. , arctan

4. , arctan

jo

i

jo

i

jo

i

jo

i

Ve RC

V RC

V L LeV RL R

V RCe

V RCL R

V R Le

V RL R

= = +

= = +

= =

+

= =

+

+

-

vi(t)

+

R1k

vo(t)

C2

20uF

-

C120uF

ZZZ

C-

C2

R R L

C1R


39/60

3

22

1 2 2

1.1

2.

13.

RZ

j RC

j RLZ

R j L

j RCZj C C C R j C

=+

=+

+= +


40/60

Bai tap TCB ch.8 - - Nguyen thanh Long1

Bai tap ch. 10 . Mach tch hp IC

10.1. Cho IC Op.amp. co o li vong h AvOL15V V =

= 180.000, c cap ien oi xngva ien the ra bao hoa cc ai) max 14obh o VV V = = . Tnh tr soien the ngo vao ln nhat Vid max ma bien o ra khong b bien dang.Giai:Ta co:

max

1477,78

180.000obh

id

vOL

VVVV

A

= = =

10.2. Mach khuech ai thuat toan Op. amp.) co o khuech ai cach vi sai Avc =8.000 va o li the cach chung Avc = 12. Tnh he so truat thai cach chungCMRR.Giai:Ta co:

8.000666,6712

( ) 20log(666,67) 56, 48

vd

vcACMRRA

CMRR dB dB

= = =

= =

10.3. Cho mach khuech ai ao dau H.1).1. Viet bieu thc Av.2. Tnh Avd vi cac tr so RIva RF R sau:I k ) RF k )a. 1 10b. 10 20c. 1 100d. 1,5 75ap so:1. FV

I

RA

R

= H.12. a. -10b. 2c. 100d. 5010.4.Cho mach khuech ai khong ao dau H.2) : Tnh :1. Tr so Av.2. Bien o tn hieu ra .Tn hieu ra co b bien dang khong?Giai:

H 1

1 Av = 1+99 = 100.2. Vopp = Av. Vipp =100(20mVpp) = 2Vpp Vopp khong b bien dang.H.210.5.Cho mach cong theo h. 3.

vovi Op-AmpRI

RF

vo

vi

20mVpp

RI

1k

RF

99k

voV3

-3V

V2

0.8V

V1

0.5V

R1 10k

R220k

R3100k

RF

100k

i1

i2

i3

i4


41/60


Tnh tr so o li Av toan mach.Giai:1 2 3

1 2 3

0,5 0,8 3100

10 20 1005 4 ( 3 ) 6

Fo

V V VV R

R R R

V V Vk

k k kV V V V

= + + =

= + + =

= =

c ieu khien bang cach ong/ mcac bac Si h. 4). Tnh o li ien thetng ng khi bac Si ong ON) vacac bac con lai h OFF).Giai:Ta co ket qua cho bi bang sau:

H.310.6. Cho mach khuech ai ien the

Si ong RF ( kOhm) Av

S1 1.000 -1000

S2 100 -100

S3 10 -10

S4 1 -1

Tnh ien the ra Vo .Giai:Tnh c:

H. 4

10.7.Cho mach khuech ai tr H. 5).

( )01 21 2

F Fo

R RV V V

R R

=

( ) ( )

( )

200 2002 150 100

8 2 ( 6 )

6

o V VV

V V V

V

= + =

= + = =

= +

H.5Thay tr so vao c:

10.8.Cho mach Khuech ai vi sai theo h.6

H. 5

vovi

S1

S2

S4

S3

R310k

R41k

R2100k

R11M

1k

-v1

vo

v2

1V

v1

2V

O.A .1O.A.2

R2

100k

R1

50k

RF

200k

R

100k

R

100k

vo

Vi

1,8VV1

R3

RF

50k

RI10k

R210k


42/60


1. Viet phng trnh vo theo vi .2. Tnh tr so vo.Giai:

Ta co:

( ) ( )2 1 1 2

F F

o

I I

R RV V V V V

R R

= =

Thay vao:

( ) ( )5

2 1,8 5 0,210

1

o

oV VV

V

= = =

=

H.6

10.9.Cho mach khuech ai ao dau vi RI = 100k va RF = 20k , Vi = 2,5V. Tnh trso vo. Cho biet mach co ten mach g.Giai:o li the:

20 0,2100

FV

I

RAR

= = =

ien the ra:Vo = - Av.Vi = - 0,2( 2,5V) = - 0,5V

V ien the ngo ra Vo nho hn ien the ngo vao Vi nen mach c goi machchia ( thay v mach nhan).10.10. Cho mach tch phan H. 7 ) , cho tn hieu vaola song vuong co bien o Vipp = 5V .1. Tn hieu ra co dang song g?2. Bien o tn hieu ra.Giai:1. Dang song vao tam giacCo bien o A = h.s:

2,5 0 / 2

2,5 / 2i

V t TV

V T t T

+ =

0

1 1to i i

dt tV vRC RC

v= =

H.7

ien the ra :

/ 2

01 2,52,52,5 0 / 222

2,5/ 2

2

T

o

Tdt t T RC fRCRC

V

T t TfRC

= = =

2.Thay tr so vao:

( )( )( )2,5

12,52 1 1 0,1

o

VVV

kHz k F = =

0Vvi

5V 1kHzvo

Op-Amp3

C0.1uF

ii

iF

Ri

1k


43/60


la dang song tam giac co bien o t -12,5V en +12,5V

vi

+ 2,5V

0-2,5V

Vo+ 12,5V

0

-12,5V

10.11. Cho mach vi phan h. 8) .Cho biet dang song tn hieu ra khitn hieu vao la:a. song tam giacb. song vuong.Giai:Ham so song ra :

i

o

dvRCv

dt=

a. Khi tn hieu vao la song tam giac , ta co:

0 / 2/ 2

/ 2

/ 2

i

tA t T

Tv

tA T t T

T

=

. ./ 2 / 2

o

d At ARC RC h sv

dt T T

= = =

H.8

Vay dang song ra:

la dang song vuong.

( )( ) ( )( )2 2 15 0, 05 2 1 3o RCAf k F V kHz V V = = =

vi

0Vvipp

4V 1kHzvo

C0.05uF

ii

iF

RF

15k


44/60


+2V

0 t-2V

vo+ 3V

0 t

-3V

a. Khi tn hieu vao la song vuong:( )

. .i

o

A h sv

dRC A RCv

dt

= =

= =

Dang song ra co dang xung nhon (gai)(ham delta ).

vi

t0

vo

t0

tan so cang cao xung cang nhon va cang khch nhau ( chu ky cang nho).


45/60

1

BAI TAP Ch11. Nang lng va Cong suat

11.1 Mach Inverter c thiet ke bang transistor NMOS va tai R L thuc tu CL.ien the cap ien Vs va MOSFET co ien tr RON, ien the them VTH1. Xac nh cong suat trang thai tnh tieu thu bi inveter khi cho 0 tac ong vaongo vao cua no.

. GIa slogic 0 = 0V va logic 1 = Vs volt.

2. Xac nh cong suat trang thai tnh tieu thu bi inveter khi cho 1 tac ong vaongo vao cua no.3. Xac nh cong suat tnh va cong suat ong tieu thu bi Inveter khi cho lientiep chuoi xung 01010101.tac ong vao ngo vao. Gia s s chuyen tiep tnhieu ( 0 1, hoac 1 0) xay ra vai T giay, va hn na T rat ln hn thihang cua mach.4. Gia s ngo vao nh cau 3, cho biet tha so nao lam cho cong suat ong bgiam neu:a. T tang theo tha so 2,b. Vs giam theo tha so 2.c. CL5. Gia s mach Inverter thoa qui luat tnh vi ien the ngng cao va thap tngng Vtang theo tha so 2 ?

IH= VH, VOL= VL. Cho biet MOSFET co RONva VTHV . Gia sL< VTH< VH< VS, chon tr so RL

1. Pstatic = 0

trong so hang cua cac thong so khac cuamach sao cho cong suat tieu thu cua mach Inverter la toi thieu.ap so:

2.2

Sstatic

ON L

VP

R R=

+

3.( )

2

2

Sstatic

ON L

VP

R R=

+ ,

( )

2 2

2

S L Ldynamic

ON L

V R CP

R R T=

+

4. a. phan na, b. phan t, c. phan na,5. Lam cc ai RL

11.2 Bai tap nay nham khao sat cong suat tieu tan bi mach logic nho. Mach gomco mach Inveter ghep noi tiep va cong NAND H. 11.1 . Mach co hai ngo vao Ava B, va moat ngo ra Z. Tn hieu vao la tuan hoan vi chu ky T4. Gia s RON cuamoi MOSFET la zero ( khong).

.

1. Ve dang song ngo ra Z vi4

0 t T . Gia s CGva CL2. Suy ra cong suat tnh thi gian trung bnh tieu thu bi mach theo Veu bang zero.s, RL, T1, T2,T3, va T44

0 t T

. Cong suat tnh thi gian trung bnh c nh ngha la nang lngtong cong tieu thu bi cong trong suot chu ky chia cho T4


46/60

2

3. Gi gia s CGva CLkhac khong. Suy ra cong suat ong thi gian trung bnhtieu thu bi mach theo Vs, RL, T1, T2, T3, va T4. ong thi gia s thi hangcua mach nho hn T1, T2-T1, T3-T2, va T4-T34. Tnh tr cong suat tng va ong thi gian trung bnh vi V. S= 5V, RL = 10 k ,CG= 100 fF, CL= 1 pF, T1= 100 ns, T2= 200 ns, T3= 300 ns, va T45. Cho biet lng nang lng tieu thu bi mach trong mot phut vi cac thong socho cau 4 ?

= 600 ns.

6. Cho biet phan tram cong suat tieu thu tong cong thi gian trung bnh giam neuien the cap ien Vs giam i 30 ?

H 11 1

5VA. . . . .

0t

5VB . . . . .0T1 t

T2T3

T4ap so

Z

VsVs

A

RL RL

CGCL

B


47/60

3

2.2

1 2 4

4

S

L

V T T T

R T

+ +

3. ( )2

4

2S

G L

VC C

T+

4. Pstatic= 2,9 mW, Pdynamic W= 87,5

5. 0,18 j6. 51%

11.3 Mot mach gom N Inverter, vi N>>1. Moi Inverter c thiet ke bangtransistor NMOS va ien tr RL. ien the cap ien Vs va ien tr khi MOSFETdan la RON. ien the them cua NMOS la VTH

2

2

Sstatic

L ON

VNP

R R

= +

. Cho biet cac inverter ghep noi tiepthanh chuoi. Tnh cong suat tnh tieu thu cua mach.

ap so:


48/60

Bai tap Ch. 2 TCB Nguyen thanh Long1

Bai tp Chng 12 : Mch DiodI. Mach chnh lu va loc12.1. Cho mach chnh lu 1 ban ky co ien the xoay chieu v i t= 40 sin , f = 50 Hz; ientr tai RL = 1 k ; diod co VD= 0,7 V khi dan.1. Ve dang song 2 au tai.2. Tnh ien the VLDCva dong ien trung bnh ILDC

1. Xem lai giao trnhcua tai.Giai:

2. Xem Vp>> VD, nen co the bo qua VDTnh :

V

.

LDC= Vp / = 0,318 Vp= 0,318 ( 40 ) = 12,72 VVa :

ILDC= VLDC/ RL = 12,72 / 1k = 12,72 mA.Chu y :

Co the tnh ILDCtrc roi tnh VLDCsau:ILDC= Ip / = Vp / ( RL) = 0,318 ( 0,04) = 12,72 mAVLDC= ILDCRL = 12,72 ( 1 k ) = 12,72 V.

12.2 Cho mach cau chnh lu toan ky ( 4 diod)co vi t= 150 sin , f = 50 Hz ,RL = 2k1. Giai thch cach hoat ong cua mach.2. Tnh ien the trung bnh vadongien trung bnh cua tai.Giai:1. Xem lai giao trnh2. ien the trung bnh cua tai:

VLDC= 2 VM / = 0,636 VM= 0,636 ( 150) = 95,40 VDong ien trung bnh qua tai:

ILDC= VLDC/ RL12.3. Cho mach chnh lu theo hnh ve:1. Trnh bay cach hoat ong va ve dangsong ngo ra ( nay u chi tiet ).2.Tnh ien the trung bnh V

= 95,40 / 2.103 = 47,70 mA.

LDC vadong ien trung bnh ILDCa. V cua tai khi:

ihd=10V ( VDb. V = 0,7V)ihd=100V ( xem VD Hng dan: = 0V).1. Xem giao trnh2. a. VLDC= - 4,275V ; ILDC

b. V= - 2,138 mA

LDC= - 44,97V; ILDC= - 22,49 mA.

50Hz

vi

150sinwt

D3

D4

D2

D1

RL

2k

+

-

50Hz

vi

Vpsinwt RL

2k

D


49/60


12.4 Cho mach chnh lu toan ky 2 diod co Vihd= 6V, RL = 10 , VD= 0,7V. TnhVLDCva ILDC1. C = 1000khi mach loc co:F .2. C = 2000 F

Giai:1. Tnh vi C = 1000uF :( ) ( )

( ) ( ) ( )

6

1 0,0051 6 2 0,7 1

4 (10)(1000)( )10

8,4 0,7 1 0,5 7,7 0,5 3,85

LDC p D

L

V V Vf CR

V

= = =

= = =

ILDC= VLDC/ RL

( ) ( )

( ) ( ) ( )

6

1 0, 0051 6 2 0, 7 10

4 4(50)(10)(2000)( )10

8, 4 0, 7 1 0, 25 7, 7 0, 75 5, 8

LDC p D

L

V V Vf CR

V

= = =

= = =

= 3,85 / 10 = 385 mA2. Tnh vi C = 2000uF

ILDC= VLDC/ RL= 5,8 / 10 = 580 mA.

12.5. Cho mach chnh lu toan ky 4 diod ( cau chnh lu) co V iac= 6 V, f = 50Hz; RL

=30 , tu loc C = 1000uF. Tnh VLDC, ILDCva Vrp1. Tnh VLDC:

.Giai:( ) ( )

( ) ( ) ( )

6

1 0,0051 6 2 1, 4 12

4 (30)(1000)( )10

8,4 1,4 1 0,166 7 0,84 6,02 6

LDC p D

L

V V Vf CR

V V

= = =

= = =

ILDC= VLDC/ RL2. Tnh V = 6 / 30 = 200 mArp V

:rp= ( Vp 2VD)( 0,005/ RL

1. ien the cuon th:

C = 7 ( 0,166) = 1, 162 V.

12.6.Cho mach cau chnh lu vi bien the ha the co t so vong 14:1 . ien the cap chocuon s la vi = 340 sinwt , 50Hz. Tnh:1. ien the nh va ien the hieu dung cua cuon th.2. Tr so nh ngc ma diod chnh lu phai chu ng .Giai:

21

1

1340 24,2 85 24,30

14

24,317,185

1, 4142

ip p

ip

ihd

nV VV V

n

VVV

= = = =

= = =


50/60


2. Tnh:PIV = Vip12.7 Cho mach chnh lu toan ky 2 diod s dung bien the co iem gia co t sovong17:1. Tnh:

= 24,30V

1. ien the hieu dung cua cuon th.2. ien the nh ngc tac ong len diod khi ngng dan.Giai:1. ien the hieu dung cuon th cap:

( )2 11

1220 12,94

17ihd

nVV V

n= = =

2. PIV:Vop = Vip VD = 12,94( 2 ) 0-,7 = 18,30 0,7 = 17,6 VPIV = 2 Vop = 2 ( 17,6) = 35,2 V.

12.8 Cho bo cap ien n gian ( chnh lu 2 diod va loc ) co t so vong bien the 18:1; ien thecap ien cuon s Vs = 220 V; tu loc C = 2000uF, RL = 10 .Tnh:1. ien the trung bnh va dong ien trung bnh ngo ra.2. ien the dn song Vrp va he so dn song r cua mach chnh lu.Giai:

1. ien the trung bnh va dong ien trung bnh:( )

( )

( ) ( ) ( )

( )

21

1

1220 12,2 2

18

2 12,22 1,414 17,28

0,0051 17, 28 0, 7 1 0, 25

12,43516,58 0, 75 12, 435 1, 243

10

ihd

ip ihd

LDC ip D

L

LDCLDC

L

nVV V

n

VV V

V V V CR

VV AI

R

= = =

= = =

= = =

= = = = =

2. ien the dn song:( ) ( )

0,00516, 58 0, 25 4,145

2,3934 2,43

2,40,14512,45

rp ip D

L

rp

rhd

rhd

LDC

VV V VCR

VV VV

VrV

= = =

= =

= = =

hay r% = 14,5%.Co the tnh trc tiep t cong thc :

r% =0,29

% 14,5%LCR

=


51/60


Nhan xet: sinh vien co the tnh nh tren vi RL lan lt 20; 50; 100 ; ta thaytai cang ln ( hay dong tai cang ln , ien tr tai cang nho) th o dn song cangln va ngc lai dong tai cang nho ( hay ien tr cang ln ) th o dn song cangnho .

12.9. Cho bo cap ien n gian ( chnh lu 4 diod va loc ) co t so vong bien the 10:1; ienthe cap ien cuon s Vs = 240 V; tu loc C = 500uF, RL = 100 .Tnh:1.ien the trung bnh va dong ien trung bnh ngo ra.2.ien the dn song Vrp va he so dn song r cua mach chnh lu.Giai:3. 1. ien the trung bnh va dong ien trung bnh:

( )

( )

( ) ( ) ( )

( )

21

1

1240 24

10

2 24 1,4 14 33,94

0,0051 33,94 1, 4 1 0,1

32,54 0,9 29,28

0, 292 292100

ihd

ip ihd

LDC ip D

L

LDCLDC

nVV V

n

VV V

V V VCR

V

VA mAI

= = =

= = =

= = =

= =

= = =

4. ien the dn song:( ) ( )32,54 0,1 3,254

3,251,88

1,7323

1,880,0645

29,25

rp ip D

rp

rhd

rhd

LDC

VV V V

VVV

Vr

V

= =

= =

= = =

hay r% = 6,45%.Co the tnh trc tiep t cong thc :

r% =0,29

% 6,45%LCR

= .

12.10. Cho bo cap ien n gian nh bai tap 2.9 nhng vi tu loc C = 2000uF va tai RL

=15 . Tnh lai VLDC, ILDCva rap so:VLDC = 27,12V; ILDC= 1,808AVrhd= 3,14 ; r = 9,6 .

12.11 Tnh he so dn song cua bo cap ien co VLDC= 27,9 V va ILDC= 50mA va tu loc C =100uF.ap so:


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( )

27,9558

50

0,29 0,29% % % 5,19%

558 100

LDCL

LDC

L

VR

mAI

rC uFR

= = =

= = =

12.12 Tnh tr so tu loc C e co c he so dn song khong vt qua 5 cho machchnh lu va loc toan ky vi ien the va dong ien cua tai lan lt la 5V va 10mA.Giai:Tr so ien tr tai:

RL= VLDC/ ILDC = 5V / 10 mA = 500Tr so ien dung :

1 0,29 0,29116

25004 3 LLC F

f rRrR= = = =

Chon C bang 100 F hoac 150F . C cang ln he so dn song cang nho hn.12.13. Thiet ke mach chnh lu ban ky va loc e co ien the DC cap cho tai la 50V vi

he so dn song 1% . Cho biet tai co tr RL = 3.3k .Giai:Dong qua tai:

ILDC= VLDC/RL = 50V / 3.3 k = 15 mAien the dn song:

Vrhd= r VLDC

= 0,01 x 50V = 0,5VTr so ien dung cua tu loc :

C = 0,58 / ( r RL) = 0,58 / (1% x 3,3k ) = 1757F

Chon C = 2000F

ien the AC cuon th cap can co :Vip= Vop+ VD 50 V

T so vong bien the phai s dung:1 1

2 2

2204,4

50s

ip

V V n

V V n= = = =

12.14. Cho biet tr so ien the nh ngc cac diod phai chu khi ngng dan trong cacmach sau ay:1. Chnh lu ban ky ( na song)2. Chnh lu toan ky 2 diod3. Chnh lu toan ky 4 diod ( cau chnh lu )ap so:

1. PIV = Vip2. PIV = 2Vip3. PIV = Vip

Giai thch:


53/60


a. Trong trng hp 1 va 3 do khi ngng dan , diod chnh lu ch b tac ong 2 cc cua no mot ien the bang ien the cuon th cap bien the V ip

b. Trong trng hp 2 , diod chnh lu phai chu ien the cua ca 2 cuon thcap hay bang 2V

.

ip II. Mach on ap Zener12.15. Cho mach chnh lu toan ky va loc co ien the ngo ra khi khong tai la V

L NL= 16,58Vva khi co tai nay VLFL

16,58 14,50,1434

14,5L LNL LFL

L

L LFL

V V VS

V V

= = = =

= 14,5 V. Tnh he so ieu tai cua bo cap ien n gian tren..Giai :Ta co he so ieu the theo nh ngha:

hay :SL% = 0,1434x100%=14,34%

Nhan xet: Vi bo cap ien n gian th he so ieu the co tr so ln, va do o khongphai la bo cap ien ly tng.Muon co he so ieu the tot ( that nho) phai s dungthem cac mach on ap.

12.16. Cho mach on ap n gian theo hnh sau , diod Zener co VZ= 20V, IZK= 5mA, IZM= 200mA. RL = 400 , RS = 100 . Tnh:1. ien the ngo ra ( 2 au tai).2. Tr so dong I1; IL; IZ .Cho biet diod Zener co hoat ong tot hay khong?3. Khi h tai diod Zerner co con hoat ong hay khong?4. Cho biet ien tr RS Giai: phai co cong suat bao nhieu e khong b h.1. VODC = VZ

2.

= 20V.

1

1

30 20100

100

2050

400

100 50 50

iDC Z

s

ODC Z L

L L

Z L

V VV VmAI

R

VV VmAI

R R

mAI I I

= = =

= = = =

= = =

Do : Zk Z ZMI I I< < nen diod Zener hoat ong tot.

3. Khi tai h IL = 0 A ( hay RL -> ) , IZ= I1 = 100mA < IZMTa co the xet theo tr so cong suat nh sau:Cong suat cua diod Zener luc nay bang :

P

= 200mA nen diod

Zener van hoat ong tot.

Z= VZIZ= VZI1= 20V x 100mA= 2000mW = 2WCon cong suat toi a cua diod Zener bang:

PZM= VZIMZ= 20V x 200mA = 4WVay PZ< PZMnen diod Zener van hoat ong tot.

-

+

-

ViDC

30V

+

VZ

20V

Rs

100

VoDC

RL

400


54/60


4. Cong suat tieu tan nhiet cua ien tr gii han Rs:

( ) ( )22

1 0,1 100 1RSM S A WP I R= = =

Vay phai chon ien tr co cong suat lam viec 2W ( chon cong suat t nhatgap oi lan cong suat ln nhat cua diod tieu tan trong mach).

12.17. Cho mach on ap nh bai 2.16. nhng v diod Zener co VZ= 20V, PZM= 10W; taiRL = 200 , RS = 20 ; ViDC thay oi t 24V en 30V. Tnh :1. Tr so dong ien cc ai va cc tieu tng ng cua diod Zener.2. Cong suat cc ai tng ng cua diod Zener va ien tr Rs..Giai:1. Taco dong tai khong oi bang:

200,1

200L ODC

L

L L

VV VAI

R R= = = =

Khi Vi thay oi, ta co dong I1max

1max

min1min

30 20 0,520

24 200, 2

20

i Z

s

i Z

s

V VV V AIR

V VV VAI

R

= = =

= = =

thay oi va co :

Do o diod Zener co tr thay oi :max 1max

min 1min

0,5 0,1 0,4

0 0,1 0,1Z L

Z L

A A AI I I

A A AI I I

= = =

= = =

Dong cc ai IZM10

0,5

20

ZMZM

Z

WPAI

VV

= = =

cua diod Zener cho bi:

Do IZmax< IZM2. Cong suat Diod Zener thay oi:nen diod Zener hoat ong tot.

( )

( )

max max

min min

0,4 20 8

0,1 20 2

Z Z Z

Z Z Z

A V WVP I

A V WVP I

= = =

= = =

Do PZmax< PZM

( ) ( )

( ) ( )

22max 1max

22min 1min

0, 5 20 5

0, 2 20 0,8

RS s

RS s

WP I R

WP I R

= = =

= = =

nen diod Zener hoat ong tot.Cong suat tieu tan nhiet cua ien tr Rs:

Vay phai chon ien tr co cong suat 10W .

12.18 Muon thiet ke mach on ap n gian trong ieu kien co san nguon ViDC= 16V ; Rs

=1k ; diod Zener co VZ= 10V; PZM= 400mW.1. Cho biet mach co hoat ong hay khong khi s dung tai RL = 1,2k va khi RL

=3k .2. Trong ieu kien mach hoat ong tot , tnh cac tr sau : I1 ; IL ; IZva PZ.


55/60


Giai:1. Khi RL = 1,2k va cha mac diod Zener vao mach ta co ien the tren tai :

1,216 8, 73

1 1,2

LLDC iDC

s L

RV VV V

RR= = =

++< Vz

Do o mach on ap khong hoat ong c .2. Khi RL = 3k va cha mac diod Zener vao mach,ien the cua tai :

316 12

1 3L

LDC iDC

s L

RV VV V

RR= = =

++> Vz

Vay diod Zener hoat ong tot va khi o ien the tren tai ( hay ien the ngo ra)bang:

VLDC= VZ3. Khi mach on ap hoat ong ta tnh c := 10V.

1

1

16 106

1

10 3,333

6 3,33 2,67

iDC Z

S

LDCL

L

Z L

V VV VmAI

kR

VV mAIkR

mA mA mAI I I

= = =

= = =

= = =

Ta co:0, 4

4010

ZMZM

Z

WPmAI

VV= = =

Do co IZ< IZM

nen 1 lan na ta thay diod Zener hoat ong tot khi chon tai bang3k trong cac ieu kien nh tren.

12.19 Thiet ke mach on ap Zener trong ieu kien sau: ien the cap ien DC thay oitrong khoang 20V 24V , ien tr tai thay oi t 100 en 500 , diod Zenerco VZ= 10V va rzkhong ang ke , dong IZmin= 14 mA, IZM1. Xac nh tr so R = 140mA.S2. Cho biet tr so cac linh kien phai chon e rap mach.e mach luon hoat ong ( trong 2 trng hp xau nhat).Giai:1. e mach on ap luon hoat ong tot Rs

max min

max min min max

iDC Z iDC Z s

Z L Z L

V V V V R

I I I I

+ +

phai thoa ieu kien:

Tnh lan lt:

min

max

max

min

10 0,1100

100,02

500

ZL

L

ZL

L

VV AIR

VVAI

R

= = =

= = =

thay vao bat ang thc tren ta c:


56/60


( )( )

( )( )

24 10 20 10

140 20 14 100

87,5 87,7

s

s

V VR

mA mA

R

+ +

3. Chon linh kien : Ta co : PZmax = VZIZ

= ( 10V) ( 140mA) = 1,4W va

( )22 2max max2

max 1max14 2,2587s

iDC Z iDC Z

Rs s s

V V V VWP I R R

RRs

= = = = =

Chon Rs = 87 - 5W va Diod Zener co VZ = 10V va PZM> 3W

12.20* Thiet ke mach on ap vi nhng ieu kien nh bai 2.19 nhng khong chotrc tr so dong IZ ma ch chon t le IZmin= 0,1 IZmax. Tnh tr IZmaxva RSe machon ap hoat ong tot trong 2 trng hp xau nhat neu tren.Giai : bai tap tren ta co bat ang thc tnh Rs , nhng gi v khong biet tr so IZmin

va IZmaxnen ta phai tnh trc IZmaxbang cach thay IZmin= 0,1 IZmax( ) ( )

( ) ( )

( ) ( )

( ) ( )( ) ( )

max minmax min

min maxmax

max minmax min

min max

max 0,1

0,9 0,1

100 24 10 20 20 10140

29 0,9 10 0,1 24

L LiDC Z iDC Z

iDC Z iDC Z Z

L LiDC Z iDC Z

iDC Z iDC

ZV V V V I I

IIV V V V

V V V V I IV VV

mA

= =

= =

= =

vao va suy ra:

Biet IZmaxsuy ra IZmin= 14mA , ta thay vao bat ang thc tren e tnh Rs nh baitap 2.19.

12.21.Cho mach on ap s dung diod Zener 1N 5240 co VZ= 10V, rz = 10 , ViDC

=20V 2V , Rs = 100 , RL = 200 .1. Tnh s thay oi ien the ngo ra2. Tnh he so ieu the Sv.Giai:1. S thay oi ien the ngo ra:

( )

2

10 2 0,1810 100

i

zo i

z s

VV

rV VV V

r R

=

= = = ++

2. He so ieu the:0,18

0.092

oV

i

VS

V

= = =

hoac tnh t :10

0, 0909 0, 9110 100

zoV

z si

V rS

r RV

= = = = =

+ +


57/60


12.22*.Thiet ke mach on ap n gian dung diod Zener co Vz = 5V, rz = 10 , PZmzx =400mW. ien the cung cap Vi = 11V 2V .1. Tnh tr so RS ( co sai so 10 ) va ien the ngo ra cc ai va cc tieu ( khikhong tai).2. Tnh he so on nh (ieu the ) va tong tr ra cua mach.3. Cho biet ien tr tai nho nhat ma mach on ap van hoat ong tot.Giai:1. Ta co:

Dong ien cc Zener cc ai :IZM= PZM/ VZ= 0,4W/ 5V = 50mA

Khi khong co tai ( IL = 0) th IZmax = I1max, ta phai chon Rs min e co cdong I1max

( )maxmax1 max min

minmax

min

13 5100

80

100 10 90

iDC z iDC zs z

s zz

s

VV VV VI R rR r mAI

R

+

+ = =

= =

nay:

Trong thc te ta chon Rs =100 ( ch pham sai so 10%).Cong suat tieu tan nhiet cua Rs :

( )22

1max 10 0,640,08RS s WP I R == =

Chon Rs = 100 -1WKhi khong co tai, IZ= I1

( )

( )

( )

maxmax 1max

minmin 1min

max min

max

11 2 580

100

11 2 540

10080 40 40

5 10 40 5,4

iDC Z Z

s

iDC Z Z

s

Z Z Z

z Zoo o o

V VV VmAI I

R

V VV VmAI I

RmAI I I

V mA V V V r IV V

+ = = = =

= = = =

= = =

= + = + == +

, nen ta co:

hay :Vo = 5V 0V = 5V 0,2V

2. He so on inh the ( He so ieu the):0,4

104

oV

i

VS

V

= = =

hay Sv% = 10%

hoac he so ieu the khi co tai khong oi:

10 0,0909 0,09110 100

zV

z s

rSr R

= = = =+ +

hay 9,1%

Tong tr ra :10 100 9,1o z sR r R= = =

3. Ta biet diod Zener se khong hoat ong khi IZ= IZK( gia s cho IZK= 0) vakhi o I1= ILmax( ng vi RLmin) va khi o Vo = Vz . Vay ta co:


58/60


max

min min

1

min

min

s

s

o LL

L L

iDC z

L ziDC z L s

L iDC Z

V VI

R R

V VI

R

V VV V R RR V VR

= =

= =

= =

trong ieu kien xau nhat ta co vi R smaxva ViDC min

min

min

5100 125

9 5

zL s

iDC Z

VR R

V V

= =

, suy ra:

Tuy nhien e bao am phai chon Rs > 125+12,5= 137,5 (sai so ien tr 10%).12.23. Xt b n p giao hon gim - tng th c tr s ln lt sau: Vi = 24 V, D = 0,4, R =

5 v tn s giao hon f = 20 kHz. L = 400 H , C = 400 F .Cho bit dng trung bnhl 100A.Gi s cc linh kin l l tng. Tnh:

1 in th ng ra Vo2. Tr s dng in cun cm3. dn sng ng ra

Gii:

1. in th ng ra:04

16V1 1 0,4

o i

DV V

D

= = =

2. Dng in cun cm:

( )

( )

( )

2

2

max 2

min 2

5,33A1

7,732 21

2,932 21

o iL

i

L i iL

L i iL

DV VIRDV R D

D DTi V VAI I

LR D

D DTi V VAI I

LR D

= = =

= + = + =

= = =

3. dn sng ng ra:

( ) ( )6 3

0,40,01 % 1%

5 400x10 20x10

o o

o o

DV V

RCfV V

= = = =

12.24. Thit k b n p giao hon tng th vi dng cm lin tc c tr s ln lt sau: Vi =12 V , Vo = 30 V, R = 50 v tn s giao hon f = 25 kHz, dn sng khng qu 1%Gi s cc linh kin l l tng. Cho bit cc tr s phi chn:1. H s nh dng.2 Lmin

3. Tr cc i v cc tiu ca dng in qua cun cm L = 1,5 mH


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4. Tr s in dung CGii:

Ta ln lt tnh c:1. H s D:

112

1 1 0,630

io

i

o

VVD

VD

V

=

= = =

2. Tr Lmin

( ) ( ) ( ) ( )

( )

2 2

6min 3

1 0,6 1 0,6 5096x10 96 H

2 2 25x10

D D RHL

f

= = = =

:

bo m c dng cm lin tc ta chn L c tr ln hn L min L = 120

:H

3. Dng in qua cuncm:

( ) ( ) ( )

( )

( )( )

2 2

6

12V1,5A

1 1 0,6 50

12 0,61,2

2 2 2 120x10 25.000

o iL

L i

V VI

R D R

i VDT A

L

= = = =

= = =

max

min

1,5 1,2 2,7 A2

1,5 1,2 0,3A2

LL L

LL L

iI I

iI I

= + = + =

= = =

4. Tr s C:

( ) ( )( )320,6

4850 25x10 0,01o

i

DC F

VR f

V

> = =

V t phi c in th lm vic WV = 2(Vo) = 2x30 = 60 VCun cm chu dng cc i > 1,5 A.

12.25.Xt b n p giao hon (chuyn mch) h th c tr s ln lt sau: Vi = 50 V , D = 0,4,L = 400 H , C = 100 F , R = 20 v tn s giao hon f = 20 kHz. Gi s cc linh kin l ltng. Tnh:

1. in th ra Vo.2. Tr cc i v cc tiu ca dng in qua cun cm L.3. in th dn sng ng ra.4. Cng sut vo, ra v hiu sut.


60/60

Gii:

1. Gi s dng in qua cun cm l lin tc, in th ng ra cho:

( )0,4 50 20 Vo iV DV= = = 2. Dng in cun cm:

( )( )

( ) ( )

max 6 3

min 6 3

max min

max minL

1 1 1 1 0, 420 1 0, 75 1.75A

2 20 2 400x10 20x10

1 1 1 1 0, 420 1 0, 75 0.25A

2 20 2 400x10 20x10

1,75 0, 251,0A

2 2

1,75 0, 27

L o

L o

L L

Ltb

L L

DVI

R Lf

DVI

R Lf

I I

i I I

I

= + = + = + =

= = = =

+ += = =

= = 1, 5A

Dng trung bnh :

( )max min 1 0,4 0,4A2

L Ltb

I IDI

+ = = =

3. dn sng ng ra:

( ) ( ) ( )2 2

6 6 3

1 1 0,40,00469

8 8 400x10 100x10 20x10

% 0,469%

o

o

o

o

DV

LCfV

V

V

= = =

=

4. Cng sut v hiu sut:

( )

( )

22

i

2020W

20

50 0,4 20

201

20

% 100%

oo

i ii

o

VP

R

WVP I

P

P

= = =

= = =

= = =

=

bt mach dien

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