-
ECA - Ch1.3 1
1.3 Cac phan t mach c ban
1.3.1 ien tr (resistor) :
R : gia tr ien tr (resistance) ,n v : Ohm () va cac c so,boi so
cua no.
la phan t tai 2 cc , co quan he u,i : u(t) R.i(t)=
10-1210-910-610-31031061091012pnmkMGT
Bang c so va boi so cua R trong he SI:
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ECA - Ch1.3 2
Cac trng hp ac biet :
i. R = 0 : ngan mach .
+
-u = 0
i
R = 0 u
i = 0+
-R =
ii. R = : h mach .
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ECA - Ch1.3 3
ien tr vach mau Rat thong dung trong thc te la gia tr cac ien tr
cho di dang ma vach mau.
310)( ValueResistor 21bbb =
valueactualin tolerance%4 =b
-
ECA - Ch1.3 4
1.3.2 ien dan (conductor)
la phan t tai 2 cc , co quan he u,i : i(t) G.u(t)=
G = 1/R = gia tr ien dan .
n v: Siemen (S) : he SI. va cac c so, boi so nh phan t ien
tr.mho : he USA.( )
()
i. G = 0 : h mach.ii. G = : ngan mach .
Cac trng hp ac biet:
-
ECA - Ch1.3 5
1.3.3 Tu ien (capacitor)
C : gia tr ien dung , v Farad (F) & cac c so cua no .
CC
ui C ddt
= La phan t tai 2 cc , quan he ap , dong tren no:
10-1210-910-610-3
pFnF(u)FmF
440pF
-
ECA - Ch1.3 6
Tu ien thc :
ien moiKim loai
dAC =
Tu n gian :
Va cac loai tu ien thc te :
-
ECA - Ch1.3 7
1.3.4 Cuon day (inductor)
L : gia tr ien cam (hay ien cam ban than) (self-inductance), v
Henri (H) & cac c so .
LL
iu L dd t
= La phan t tai 2 cc , quan he ap dong tren no :
10-1210-910-610-3
pHnHHmH
-
ECA - Ch1.3 8
Cuon day thc : ien cam n gian :
2N ALd
= Va cac loai cuon day : loi khong kh va loi la sat t :
-
ECA - Ch1.3 9
1.3.5 Ho cam (mutual inductance)
Mo hnh mach cua he 2 cuon day co tng tac ve t.
1 21 1
2 12 2
u L M
u L M
di didt dtdi didt dt
= =
Phan t tai 4 cc , co quan he ap , dong tren cac cc:
C 1 2M k L L (H)=C0 k 1<
-
ECA - Ch1.3 10
Xac nh cc cung ten: Cc cung ten (ky hieu : * , , ) : xac nh
chung t chieu quan day.
-
ECA - Ch1.3 11
Xac nh dau cua he phng trnh a) Dau cua Tphan ien ap do cam ban
than :
b) Dau cua Tphan ien ap do cam ho cam :
a) b)
c) d)
-
ECA - Ch1.3 12
1.3.6 May bien ap ly tng (ideal transf.)
a) Mo hnh: co 2 ieu kien e may bien ap thc c xet vi mo hnh may
bien ap ly tng .
-
ECA - Ch1.3 13
b) He phng trnh may bien ap ly tng:
T thong moc vong qua 2 cuon day la nh nhau:
1 11 1
2 22 2
u ( ) N ( )u Nu Nu ( ) N ( )
dt tdtdt tdt
= ==
1 2
2 1
i Ni N
=1 1 2 2u ( )i ( ) u ( )i ( ) 0t t t t+ =
May bien ap khong ton hao :
Neu ta at : 21
NnN
=
1 1
2 2
1 2
2 1
u N 1u N ni N ni N
= = = =
-
ECA - Ch1.3 14
1.3.7 Nguon oc lap ly tng
a) Nguon ap oc lap ly tng:
Ky hieu: INDEPENDENT VOLTAGE SOURCES
e(t) hay E = sc ien ong cua nguon ap , v (V).
nh ngha:i
u e(t) ==
-
ECA - Ch1.3 15
Phan loai nguon ap :
Tuy thuoc dang cua sc ien ong e(t) :
DC
AC
Pulsed
Ramp
time
voltage
-
ECA - Ch1.3 16
Phan t thc cua nguon ap :
Plug-in 220 V
1.5 V
9 V
Car Battery Electric Power Plant
13,500 V13,500 V
Solar Cell
Power Supply
-
ECA - Ch1.3 17
b) Nguon dong oc lap ly tng
Phan loai: DC (Direct Current) , AC (Alternating Current)
nh ngha:u
i J(t) ==INDEPENDENT CURRENT SOURCE
Ky hieu : J(t) = gia tr dong ien , v (A).
-
ECA - Ch1.3 18
Phan t thc cua nguon dong : Thng khong phai la mot phan t mach
thc ma la mot
mach ien (mot mang mot ca tch cc) , co tnh chat tng ng nguon
dong.
-
ECA - Ch1.3 19
1.3.8 Nguon phu thuoc ly tng
nh ngha nguon phu thuoc (dependent source) : phan t 4 cc
Phan loai nguon phu thuoc : co 4 loai
-
ECA - Ch1.3 20
a) Nguon ap phu thuoc ap (VCVS) :
Tn hieu ap b phu thuoc Sc ien ong cua nguon ap phu thuoc
He so k1 khong th nguyen
-
ECA - Ch1.3 21
b) Nguon dong phu thuoc dong (CCCS) :
Tn hieu dong b phu thuoc Dong ien cua nguon dong phu thuoc
He so k2 khong th nguyen
-
ECA - Ch1.3 22
c) Nguon dong phu thuoc ap (VCCS) :
Dong ien cua nguon dong phu thuoc
Tn hieu ap b phu thuoc
He so k3 th nguyen S
-
ECA - Ch1.3 23
d) Nguon ap phu thuoc dong (CCVS) :
Sc ien ong cua nguon ap phu thuoc
Tn hieu dong b phu thuoc
He so k4 th nguyen
-
ECA - Ch1.3 24
Phan t thc cua nguon phu thuoc :
Thong thng la mo hnh toan cua cac phan t ban dan .
-
ECA - Ch1.3 25
1.3.9 Phan t nguon thc te
Cac nguon ap thc hay nguon dong thc thng khong thoa t/chat cua
nguon ly tng . V du ap ra thay oi theo dong.
Do o , phan t nguon thc phai co s o tng ng:
Nguon ap thc Nguon dong thc
