thu~t toan III m~ch
Ie wyen Hoh rift quan tn,mg, c6 rAt nhieu ling dl,lng.
Khuech d~i tuyen tfob ph6 bien nhllt I. IC 741. Cae IC 741 duqc chf tlJO trong cae lo~i vo
bQc khac nhau. do nhit!u hang kh8.c nhau sim xu.!t.
moh 5.32 bieu thj m..,t s6 Ie 741.
56 cae bl>
khuech d<,li thu~t
toan chua trong mQt vo bqc co th~
la. 1 (lo<,li dcm nhu:
~A 741. J.1f\ 709.
n081. LM 30lA, 3130 ... ); <6 th~ iA 2. 4 (lo~i kep. nhu LM 358, RC 4558,
LM 324, MC
3403 ... ).
Cb6 t: Khu!<h d,i thu.t t04n Ill. Ie
tuytn Hoh nhung Ie
tuyen Hoh t:6 nhi~u
IO{li tblle hi¢n cae chuc nang kh4c nhau: khufch dl!:i,
Can bAing .
2 • (+)
3 > 6
jfJ&m 0 §jChAn bO
(_) can -. bAng J.1A741HC lF351N lM318A CA. 081A
LF356
~(ằ
(-)U
lF353N HA17082PS lF442CN no12P
IU'C803
(ằ
(.)
ChAnbO
""'-..a • ....-~5 can bAng 0 (-)
J.1A741HC J.1PC151A LF411CH AD5474 ...
(.) lF412C lF442C
t,o dao dQng, tllch s6ng, 60 ap ... Ttn 8Qi khufch d,i thu~t
HlIIh 5.32 : M~t sO J.:Irueclr d~i th144t todn 741
toan III do ml!.ch di¢n nguytn thuy dllqc sir dl/-ng d~ thl!c hi¢n cAe ph6p tiob cQng. lrlr.
DhAn. tich phln ... trong may tioh.
MQt s6 th6ng s6 caban cua khu&h d'1-i'thu~t tolin ~ 741:
Thong so !lit 741 H~ s6 KE> KOA 200000
TrCl khang vilo Z. '''n I, R, •
TrCl khoi!mg ra Z, 120(1
Dili thong 1MHz
£)i~n ap ngu6n nuOi 5V ± 18V
£)i~n il.p veo cl/c d,1 ± 13V
-!"vu._ -I.
I
£)i~n ap ra cl,lc d,1 ± 14V
DI) tAng triJCng U, 0,5 V/j.l.S Hilll! 5.33: Khufch dlJi ddo dung khuech dlJi thugt toall
a) Kh~tch dgi dJo
Sa d6 mlJ.ch nhu hlnh 5.33. Tin hi~u vao dUB vito dliu daD. Di~n trO R~ HUn nhi¢m V1,I phAn h6i (h6i tilp) am til dAu ra v~ dliu vlo daD.
Coi khu&b dlJ..i thu~t toin 18. Ii tuOng thl Zv ~co nen Iv ::t!0; aUv =0.
Suy ra U. = U .. =0.(n6imat) TIJ..i nut cUu vito daD c6:
1\ =12 +Iv ~J2
U.-U_~U_-u" (U.=O)
"R\ R2 U v -Ur
-~--
R\ R2
U R
KOA =_-_r =--'
Uv R\
IMu (-) th~ hi~n tin hieu ra, bi daD pha so vm tm hieu vito.
U =_R,U , R •
I
(5.25)
(5.26) - Thl!c tl Iv * 0 nen S\lt ap do Iv gAy ra tren Rio Rl se tlJ.O sai s6 cho he s6
khulch dlJ.i KOA ' ~ lolJ.,i triiAnh huang nay, d4u vAo (+) duqc n6i qua mQt dien lra R xu6ng mal (bloh 5.34). Dien tra R dUQ'c CbQD bAng di~n tra wang duao.g cua (R , /I R,).
R R, +R2 - (5.27)
Khi d6, 8\1t ap gAy 1Xri. Iv tren cac dien nit mAc a d4u vao (-) 5i! bAng nhau va lIlIJ.ch khu&h ~i thu.t toon se dugc cAn bAng.
- KID R, =" R, thl Ko. = -I vA ~h khut'cb do!i dolo IIIIIt ella" ~ tn¥b lljp c6 dolo ,in hi~u (b¢ dio da'u tin hi~u) .
.,
R,
<
R,~ ff
u. -
I <
HillA 5.34: Mqch loqi Irit sa; sff lhllech d(li HiRh 3.35: M<,ch bien dd,. dll"S . up - Khi R, = 0 (blnh 5.35) thl: "
111'::112= U_;U, r =_~r ~Ur , =-R2Iv (5.28)
Day til mC;\Ch biln ddi dong -tip c6 dio pha: di~D lip ra ti l~ vOi dbng vao.
b) Khuech dt;li kMng ddo
Sa d6 m~eh nhu blnh 5.36. Tin hi~u vAD dua vAD dltu khOng dio .
- '.
.,
<
Hi"h 5.36: KIu4(ch dl,ii I:MnB dJo dung kh~£ch dl,ij Ih~t lo6n
u.!ZI--"'<
f
(5.29)
. R Ko .... =1+-'
R,
Khi R, = co (lW m~ch). Rl = 0 (ngin m,ch) tltl Ko" = 1 vA Ur = U y.
Mi).ch k.hu~ch d,i khOng dao tra thlnh mlJ.ch 13p 1,i
di~n ap. Tin hi~u ap dJ.u ra
l~p l.i tin hi~u c1p d4u vila (hlnh 5.37).
"
u" - -I, •
(5.30)
>--~-f!lu,
1 -
- M,ch k.hu~ch d,i con gQi la khau Ii I~ P (Proportional).
c) Khuech d{Ji c~ng
Hb." 5.38 : Mt;lch I:hll~c" df!i ct'ng dUlig thu.leh dt;Ji rhu~t rod"
Sa d6 m~ch nhll hlnh 5.38.
Suy ra:
c6 :
Coi Z, ="', 1.= 0 Ihl: 1,+1,=1' vaU, =U. =0.
Uvl - U_ + Uv2 - u_ U_ - Ur
R, R2 R'
Uv1 Uv2 Ur - + - - = - -
R, R2 R'
• R' Dat Q.=-
• I R ,
( R' R' )
Ur =- - Uv1 +-Uy2
R. R2
Ur =-(a,UYI +a2Uy2) hay t6ng qrult: U, =-La,U,;
N~u ch9D R, = Rl = R' = ... thi cac aj = 1 vi}.:
(5.31) (5.32) (5.33)
(5.34)
•
Day IA m~ch cQng dao.
~ c6 m~ch cQng khOng dilO. ta dung sO d6 hinh 5.3.9.
V6i khue'ch d~i thu~t tOOn If [trang thi lv+ = Iv. = 0 (vi
Zv=c.o) nen U+ = U., ta c6 (thea m~eh ph4n lip R - R'):
U = R U =u
- R+R' r +
DiU: . c t = -R' R
u~ !.!.~
u" ~~
I+u ( )
co: Ur = R2Uvl +RIUv2 Rt+R2
Khi chQn R, =R2 thl:
I+u( )
Ur=-2- Uvl+bv2
hay tOng quat cho n d4u vao:
+
~u,
f
R' R
(5.35) (5.36)
(5.37)
U,=I~U:tU,; (5.38)
i_I
d) Khui'ch dgi Irir
Sa d6 m/l.ch nhu hlnh 5.40. 1m bi¢u vile a ca 2 cUa vAo dAo vii khOng dao.
Ap d~ng cae bii!u thiic di¢" lip ra trong tnrong hqp m4c khODg <hIo (5.29) vil dao {5.26) Wi nguyen Ii x/!p cMng ~i tMu ra, ta cO:
U=U R R,+R' U,~
r v2R+R R vR
~ I '-..---' I
U+ Ur_
Khl chQn R' = ctR, va R = aR2 thl co:
U, = u(u., - U.,) (5.39)
ehu y :
C6 the: sir dl,mg
m~ch c~ng blob 5.38 dt thge
hi~n phep trll' khi U v2 d Il'Q'c dao dau theo
m~ch hloh 5.33 v6i KOA = 1.
M~ch obit tren hlnh 5.41.
R
R
+
Rã
+
R
Hi"h 5.40 : M{lch khuech drp' tril dllng khuleh dqi thu4t toon
u.,
Rã
R, +
+
Hi"" '.41 .. M(lch trildilng 2 klJll.ech ~i thu4t todll
e) Mq.ch tickphdn
Sa dd m~ nhrrblnh S.42.M4ch clmg¢ 1A khAu !leb pbAn I (lntergral). T~i lUu vlod8.oc6 :ir =ic(vl ~=O)
VlU.=U .. =Onen:
Uv =_C dUr . R d t '
dU = - - U dt 1
r RC v
I I )1
U = - - f u dt=--fu dt , R C ' •
o ' 0
vai hang s6 thai gian ella m~ch tich pMn : t:o: RC f) Mqcll vi pluill (mqch d{Jo ham)
So do m~ch nhu hlnh 5.43a. Mi;lch con 8Qi fa khau vi pMn hay d~o nam D (Differential).
T~i d<iu vao dao c6:
i" ::: i, (vI coi Z, = OCI, Iv::: 0):
cdU• =-~
dt R
d d
V,y: U =-RC-U =.-,-U
. r dr Y dt Y
v{:ti Mng s6 thai gian eua mt.lch VI pMn:
t = Re.
Khi tin hi¢u van co titn 56 caD, tI,I C c6 dung kMng nhi>
(X<=_I_) c6 the
2.tC
gay ng<ln ml:tch dau van va m~ch k~m On dinh. De khac phl,lC
Onh tr~g Day. ditu Vao dlIQC n6i them di¢n trb Rlf (hloh 5.43b).
I, C
u,"'- - I
.J f
.. c
Uv~
.J f
(MO)
(5.41)
f
(5.42)
I, R
- •
>----91u,
- f
R
f
Hid 5.43 : M(lcit I'i p/ldn dill/a 1:.IIIII'ell J",i tllllql 100i/l
CAU H61 CHUONG 5