Download - On Tap Ly Thuyet Mach
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KHI NIM C BNI/ Ngun c lp: 1. Ngun p:A
2. Ngun dng: P = U.I < 0 L tng: Ri = 0 Khng l tng: Cng thc phn p: L tng: Khng l tng: Cng thc phn dng:
B
II/ Ngun ph thuc: 1. Ngun p ph thuc vo p (AA) 2. Ngun p ph thuc vo dng (AD)
= 3. Ngun dng ph thuc vo p (DA)
= 4. Ngun dng ph thuc vo dng (DD)
=
=
III/ Cc thng s r, L, C, M 1. in tr: () () () () () () 2. in cm: () () ()
3. in dung: () () ()
4. H cm:
Du (+) khi 2 dng cng chy vo (hoc ra) u cng tn (*). u cng tn th hin chiu qun dy.
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IV. Cc thng s dng phc: Sut in ng
(
)
(
)
(
)
Nu tc ng l cos: ( ) Nu tc ng l sin: ( )nh lut Ohm Tr khng
( )
Dn np
(
)
in tr
in cm
( ( ( ( ) ) ) )
in dung
H cm
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CC PHNG PHP PHN TCH MCH INI/ nh lut Kirchoff I: Tng i s cc dng ti 1 nt bng 0. - Ly du (+) khi dng chy ra khi nt - Ly du (-) khi dng chy vo nt II/ inh lut Kirchoff II: Tng i s cc in p trn cc nhnh trong 1 vng kn bng 0. III/ Phng php in p nt: - C s: nh lut Kirchoff I - n s trung gian: in p nt - n s cui cng: Dng in trn cc nhnh Dng cng thc bin i nt tnh dng in cc nhnh t in p cc nt. Cch lm: - Chn nt gc bng 0V - Vit phng trnh cho cc nt, vi n s l in th cc nt: V tri: Ly in p nt ang xt nhn vi tng dn np thuc nt , ri tr i cc tch gia in p nt ln cn vi dn np chung ca nt ln cn v nt ang xt. V phi: Tng i s cc ngun dng c bin i t cc ngun p c ni vo nt ang xt. Du (+) khi chiu ca ngun dng ch vo nt ang xt. Du (-) khi chiu ca ngun dng i ra khi nt ang xt. - Gii h cc phng trnh va vit. - Dng cc cng thc bin i nt tm dng in trn cc nhnh. V d: - Chn - Vit phng trnh cc nt: ( ) Nt A: Nt B: Nt C: Nt D: Ta c h phng trnh: ( ) ( ( - Gii ra - Cng thc bin i nt: ) ( ) ( )) ( ) ( ) ( . .( . .( ) . ) . )
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IV/ Phng php dng in vng: - C s: inh lut Kirchoff II - n s trung gian: - n s cui cng: Dng cng thc bin i vng tnh dng in cc nhnh t cc dng in vng V d:
- Vit phng trnh cho cc vng: ( ) Vng 1: ( ) ( Vng 2: ( ) ( Vng 3: Ch ti du ca
( )
) ) (
( (
) ) )
( ( ( ( ) )
) (
( (
) ) ) (
( (
) ) )
)(
)
(
)
- Gii ra - Dng cng thc bin i vng:
V/ Nguyn l xp chng: Mch in c cha nhiu ngun tc ng, c th coi do tng ngun tc ng (cc ngun khc ngn mch), ri cng cc kt qu li.
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VI/ nh l ngun tng ng: Mch in c cha nhiu ngun tc ng c ni vi phn cn li ti cp im AB, c th thay th bng 1 ngun sut in ng bng .
- Ct nhnh c hi ra khi mch ti cp im AB - Tnh bng cc phng php hc - Tnh - V s tng ng, lp nhnh b ct vo s v tnh I * Ch : Cch tnh c 2 nhnh song song:
Du (-) khi 2 dng cng chy vo (hoc ra) u cng tn
VII/ Bin i Laplace: 1. Bin i R, L, C trong min p in tr
u(t) = r.i(t) U(p) = r.I(p) in cm
() in dung
()
( )
( )
( )
( )
()
()
( )
( )
*
() +
( )
( )
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2. Bin i Laplace ca mt s hm s c bn: Hm gc Hm nh
Hm gc () ()
Hm nh * ( ) ( ) ( ) () +
() ( ) ( ( * () () ( ) )
(
) ( ) () () () {
() {
(( )
)( ) ( ) ( )
1
3. Bin i Laplace ngc - Heaviside: ( ) ( ) ca ( ) l im 0 ca ( ), c th nm bt c ch no trn mt phng phc. ca ( ) l im cc ca ( ), ch c th nm na mt phng tri v trn trc o. c nghim n ( ) () b) ( ) c nghim bi ( ) () ( [ ( )(()
- Nghim - Nghim a) ( )
( ) ( )
) )] )]
[ ( )(
c)
( )
c cp nghim phc lin hip () | ( ) | ( ) ( ) ( ) ( )
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MCH QU rC, rL, rLCNgun sut in ng bin thin theo thi gian, p ng ra ca mch bao gi cng c dng: () Trong : ( ) l ch xc lp l ch qu ( ) ( ) ( )
l hng s thi gian
l in tr tng ng ca ton mch (lc sau) nhn t cp im L (hoc C), vi iu kin ngn mch Eng, h mch Ing. Di tc ng 1 chiu, C coi nh h mch, L coi nh ngn mch. Cc bc gii: kha K trng thi ban u, xc nh cc iu kin u ca bi ton: ( ) ( ). V li m hnh trong min p. Chuyn K n v tr mi, vit phng trnh p ng ca mch trong min p. Gii phng trnh. Dng Heaviside chuyn F(p) f(t). Kim tra li bng cng thc trn. V d 1: Cho mch in nh hnh v, lc u kha K m. ( ) ( ). ng kha K, tm ( ) Khi K m, ( ) V li mch trong min p ng kha K, ta c phng trnh in p nt: ( ) ( * ( ) ( ( ) ( ) () ( () ( ) * ( ) ( ) ( { ( ) ( ) ) ( ) ) ( ) ( )
() ( ) ( ) ( ) Kim tra li: ( ) ( )
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V d 2: Cho mch in nh hnh v, lc u kha K ng. ( ) Khi K ng: ( ) ( ) ( )
( ). M kha K, tm ( )
Khi K m: Theo nh lut Kirchoff II: ( )( ( ) ) ( ) ( )
( ( ) ( ) ( ) ( ( ) ( )
)
( ) ( )
*
{ ( ) ( )
( )
Kim tra:
()
( )
( )
( )
V d 3: Cho mch in nh hnh v. ( ) p dng nh lut Kirchoff II: () () ( ) ( )( ( ) a/ ( ) () () () ( ) () ( ) ( ) ( ) ) ( ) ( ) ( ) ( ) ( )
Tm i(t) = ?
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( ) ( ) ( ) ()
(
)
( ) ( )
( ( ) ( )
) ( ( ( ( ) )
{
) ) ) ( ) ( ( ( ) ) ) ( ) ( )( )
b/ ( ) e (t) = 0 ( ) ( ( ( (
( ) ) ) )
()
V d 4: Cho mch in nh hnh v. p dng nh lut Kirchoff II: () () () () () ( ) ( a/ ( ) ( ) ( ( ) ( ) ( ( ) ( ) * ( ( ) ) { ) ( ( ) () ( )) ( ) ) ( )
( )
()
()
(
*
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b/ ( ( ) ( () ) (( )
)
(
)
( ) )
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MCH DAO NG NI. Mch dao ng n ni tip: ( ) ( ) ( ) ( )
( ( { () [ (
)( )(
) )
( )
*
(
*]
( ) a/ Dng in cng bc: () ( ) b/ Dng in qu : () ( )
Lng suy gim loga t nhin ca dao ng tt dn: .( )
Thi gian tt ca dng qu : in tr ti hn
:
Khi
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c/ Dng in tng hp:
Khi = 0 th
()
(
)(
)
(
)
Di thng l di tn s m
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II. Mch song song i ngu vi mch ni tip: ( ) Cc phn t i ngu: Xy dng mch i ngu: Ly 1 im A trong mch v 1 im B ngoi mch. Ni AB, mi ln ni ct qua mt phn t (xem hnh minh ha) ngha: Nu c 2 mch i ngu th tnh cht mch ny c th c suy ra mt cch i ngu t mch kia.
Ni tip 1. Tr khng ( ( , 2. Dn np | { 3. Phm cht ti 4. Di thng 4. Di thng ) ( 2. Tr khng ) ) ( ) ( { 1. Dn np (
Song song ) ) ( ) ( )
|
|
|
{ 3. Phm cht ti
5. lch tn s
5. lch tn s
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6. Dng in 7. in p trn r 8. in p trn L 9. in p trn C ( )
6. in p 7. Dng trn R ( )
( )
8. Dng trn C 9. Dng trn L
10. in p v dng in ti }
10. in p v dng in ti }
(
)
in tr tng ng ca mch dao ng n song song (thc t)
V d 1: Cho mch in nh hnh v. () ( ) a/ Tnh ( ) b/ Cho Em = 20V, f = 400kHz. Tnh Um,
?
Gii: a/ Bin i mch nh hnh v trn ( )Page 14
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R= Ri // R = 5k b/ Vi Em = 20V
R// ( )
V d 2: Cho mch in nh hnh v.
( ) ( )
a/ Cho Ingm = 5mA. Tnh R, C? b/ Cho Q = 10. Tnh c/ Tnh Um vi f = 200kHz.
Gii: a/ Ti f = 0 th ( ) ( )
b/
c/ ( )
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TH BODENguyn tc chung ca th Bode l v p ng tn s ca mch (bin v pha) bng cch tng hp trc tip cc c tuyn tn s thnh phn ng vi cc im 0 v im cc ca H(p). ( ) ( ) [ ] c tuyn bin : ( ) c tuyn pha: ( ) [ ] Cc c tuyn ny c thc hin trn thang t l logarithmic i vi , k hiu l trc [Decade] ( )
nh v tr ca trn trc : a v dng ( ) n quyt nh Decade, nmg trong Decade (n; n+1) m quyt nh v tr ca trong Decade , m = 2 th nm ti 1/3 Decade, m = 5 th nm ti 2/3 Decade V d: nm trong Decade (3; 4) nm ti v tr 1/3 Decade th Bode ca mt s hm s (xt im 0): 1. ( ) ( ) [ ] ( ) { 2. ( ) ( ) ( ) Nu ( ) ( ) th ng cho 20dB/D
khng i qua gc ta m i qua Nu ( ) th ng cho c dc 40dB/D v i qua 3. ( ) | | [ ( ) ]
( )
(
[ ]
)
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( )
(
)
Nu
( ) ( ) ( ) (
th th bin khng thay i ) th dc ca th bin l 40dB/D.
nhng th pha i xng qua trc honh Nu
4.
C cp nghim phc lin hip. Nu cp nghim phc ny nm na mt phng tri th: ( ) [( ) ]
(
( )
)
( )( ( * )
Nu cp nghim phc nm na mt phng phi th th bin khng i, nhng th pha ly i xng qua trc honh.
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5.
( ) | |
( )
(
)
( )
arg (
*
,
Mt s ch : 1. a thc bc nht: ( 2. a thc bc hai: ( ( ) ( ) ( ) ( ) ( ( *( ) * * ) ( *
th Bode ca im cc (nghim mu s) i xng vi th ca im 0 qua trc honh. V d 1:
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V d 2:
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(1)
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MNG BN CC
I/ H phng trnh tr khng h mch:
i vi s hnh T:
II/ H phng trnh dn np ngn mch:
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i vi s hnh :
Bn cc i xng: Khng phn bit c ca 1 v ca 2. Khi :
V d: Xt s tng ng hnh X c mng 4 cc i xng: | Theo Kirchoff II: ( )
| {
(
)
III/ H phng trnh c tnh truyn t:
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a = detA = -1 i vi s hnh G: ( *
i vi s hnh G ngc:
IV/ H phng trnh c tnh truyn t ngc:
b = det B = -1 V/ H phng trnh c tnh hn hp:
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VI/ H phng trnh c tnh hn hp ngc:
Lin h gia cc thng s ca mng 4 cc:
c im ca bng: + Trong mt hnh ch nht bt k ca bng, tch cc thng s trn ng cho bng nhau. VD: -h21.z12 = h12.z21
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VII/ nh l Batlet dng cho 4 cc i xng: Mi 4 cc i xng u c th c thay th bng s tng ng hnh X, vi cc phn t c xc nh nh sau: + B i 4 cc i xng thnh 2 na bng nhau + - Dy dn thng b ct c ngn mch. - Dy dn cho b ct c h mch. + - Dy dn thng b ct c h mch. - Dy dn cho b ct c ngn mch. V d:
VIII/ K thut tnh ton - Chun ha gi tr: S dng cho 4 i lng: R, L, C, [ ]
+ Chn 2 trong 4 i lng trn lm chun, ri tnh 2 i lng cn li theo 2 cng thc trn. + Tnh ton cc gi tr tng i, gii bi ton bng cc gi tr tng i . + i gi tr tng i thnh gi tr tuyt i (nhn vi ) V d: Chn 2 gi tr chun: { Tnh 2 gi tr cn li:
{ Xc nh cc gi tr tng i:
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Tnh ( ( ( ) ( IX/ Ni ghp cc 4 cc: 1. Ni tip Ni tip: ( * * ) ( ( ( ( ) ) )( ( ) )( ( ) ) ) )
2. Song song Song song:
3. Ni tip Song song:
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4. Song song Ni tip:
5. Dy chuyn:
(1)
(2)
(3) (4) (5)
ng dng: Bn cc phc tp c th c tch thnh cc bn cc n gin. Cc bn cc n gin ny ni vi nhau theo cc cch trn. Cc loi 4 cc n gin: Hnh T, hnh , hnh I, hnh G, hnh G ngc, hnh =, Transistor
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V d: Cho mng 4 cc nh hnh v, xc nh cc thng s dn np ngn mch ca mng. Cho Gii:
v thng s truyn t
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X/ Hm truyn t:
XI/ H s truyn t:
Vi 4 cc i xng: ( )
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XII/ Cc thng s sng (Thm ch s 0 vo thng s thng):
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Xc nh thng s sng:
( ) Ch : ( ) Vi 4 cc i xng c phi hp tr khng 2 ca: Nu l 4 cc i xng vi s tng ng mch cu:
V d 1:
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V d 3: a.
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XIII/ Bn cc tuyn tnh khng tng h: 1. H phng trnh tr khng h mch: ( {
) ( )
(
) ( ) ( )
2. H phng trnh dn np ngn mch: { ( ( ) ) ( ( ) ) ( )
3. H phng trnh c tnh hn hp:
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4. V d v bn cc khng tng h: a. Girator: K hiu ca Girator nh hnh v: H phng trnh tr khng: { ( ) ( , ( +
Cc thng s mang ngc du vi iu kin tng h Girator l bn cc phn tng h. () ( ) Cng sut tc thi p(t) = 0, Girator l phn t qun tnh, khng tng h nhng th ng. Quan h gi tr khng vo ca ny vi tr khng ti ca kia: nu r l s thc th 2 phn t tr khng i ngu. b. Mch bin i tr khng m (NIC):
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c. Transistor:
(
)
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d. Mch khuch i thut ton (Operational Amplifier)
Mch KTT l tng: ( )
{ Mch KTT khng l tng:
{
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V d 1: Xt mch khuch i thut ton nh hnh v:
()
()
()
V d 2: Mch cng v mch tr: Mch cng:
Mch tr: ( )
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V d 3: Xt mch khuch i thut ton: Xt nt 3: ( ) Xt nt 4: ( ) ( ) M ( ) T (2) (3) ( ( ) a/ { ( ) Mch lc thng thp ( ( ) ( )( ) ) )
( )
b/ { ( ) Mch lc thng cao
(
)
(
)(
)
c/ { ( )
(
) ( )( )
Mch lc thng di
Ba mch trn l Khu lc tch cc RC bc 2
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MCH LC TN SB lc cho 1 hay nhiu di tn hiu i qua (di thng), chn cc di tn s cn li (di chn). Tn s gia di thng v di chn l tn s ct (cutfreq) ( ) { ( ) | | {
Mt b lc phc tp c th chia thnh cc b lc n gin (hnh T, hnh )
iu kin di thng:
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I/ Mch lc loi K: ( )
1. Mch lc thng thp:
2. Mch lc thng cao:
3. Mch lc thng di:
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4. Mch lc chn di:
II/ Tr khng sng cc b lc loi k: 1. Mch lc thng thp: a/ Hnh T:
Trong di chn: mang tnh in cm ( ) Trong di thng: mang tnh in tr ( )
b/ Hnh :
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Trong di chn: mang tnh in dung ( ) Trong di thng: mang tnh in tr ( )
2. Mch lc thng cao: a. Hnh T:
Trong di chn: mang tnh in dung Trong di thng: mang tnh in tr
b/ Hnh :
Trong di chn: mang tnh in cm Trong di thng: mang tnh in tr
3. Mch lc thng di:
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4. Mch lc chn di:
III/ Suy gim sng, dch pha sng ca cc b lc loi k: Trong di thng:
Trong di chn:
1. Mch lc thng thp:
3. Mch lc chn di:
2. Mch lc thng cao:
4. Mch lc chn di:
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IV/ Mch lc loi M:
1. Xy dng b lc loi m: a/ Chuyn ni tip t Tk sang Tm: + Gi li 1 phn + Chuyn phn cn li mt cch ni tip xung nhnh song song to thnh
sao cho
b/ Chuyn song song t k sang m: + Gi li 1 phn + Chuyn phn cn li mt cch song song ln nhnh ni tip to thnh
sao cho
2. Cc loi b lc loi m: a/ Lc thng thp:
{
{
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b/ Lc thng cao:
{
{ c/ Lc thng di:
{
{ d/ Lc chn di:
{
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{ 3. B phi hp tr khng:
Phi hp tr khng vi Ri = Rt = const
Tnh
( ):
ph thc vo m ( 0 < m < 1), vi m = 0,6 th tr khng sng bng phng trong sut di thng.( )
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Tnh
( )
ph thc vo m ( 0 < m < 1), vi m = 0,6 th tr khng sng
bng phng trong sut di thng.
4. Suy gim sng:
a/ Lc thng thp: b/ Lc thng cao:
c/ Lc thng di: ( *
d/ Lc chn di: ( *
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B lc loi K, cng i su vo di chn, B lc loi M, cng i su vo di chn, V. Thit k b lc y :
. Tuy nhin cng gim. Tuy nhin
chm. nhanh ti .
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V d: Thit k lc thng thp y c Phi hp tr khng gia ngun v ti c v c suy gim sng cng i su vo di chn cng tin ti Gii: 1. Lc K: ( )
( ) ( )
T (1) (2) suy ra:
2. Lc M:
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{ 3. Phi hp tr khng: (thay m = 0,6)
{
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MC LCKhi nim c bn I. Ngun c lp II. Ngun ph thuc III. Cc thng s r, L, C, M IV. Cc thng s dng phc Cc phng php phn tch mch in I. nh lut Kirchoff I II. nh lut Kirchoff II III. Phng php in p nt IV. Phng php dng in vng V. Nguyn l xp chng VI. nh l ngun tng ng VII. Bin i Laplace Mch qu rC, rL, rLC Mch dao ng n I. Mch dao ng n ni tip II. Mch song song i ngu vi mch ni tip th Bode Mng bn cc I. H phng trnh tr khng h mch II. H phng trnh dn np ngn mch III. H phng trnh c tnh truyn t IV. H phng trnh c tnh truyn t ngc V. H phng trnh c tnh hn hp VI. H phng trnh c tnh hn hp ngc VII. nh l Batlet dng cho 4 cc i xng VIII. K thut tnh ton Chun ha gi tr IX. Ni ghp cc bn cc X. Hm truyn t XI. H s truyn t XII. Cc thng s sng XIII. Bn cc tuyn tnh khng tng h Mch lc tn s I. Mch lc loi K II. Tr khng sng ca cc b lc loai K III. Suy gim sng, dch pha sng ca cc b lc loi K IV. Mch lc loi M V. Thit k b lc y : Mc lc Trang 1 1 1 1 2 3 3 3 3 4 4 5 5 7 11 11 13 16 22 22 22 23 24 24 25 26 26 27 30 30 31 34 40 41 42 44 45 49 52
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