) .Thevinen's Theorem VTh RTh :
RTh I R :=I VTh RTh + R
: )( : ) ( ) 1-
).(VTh2-
( ) RTh RTh (. ) ( VTh 3-
RTh , :VTh RTh + R
=I
:
Complex Circuit .output Open ) 1-
. VTh2-
( ) ( RTh . , 3-
VTh , RTh RL . )1(: a,b :
a,b ) (open a,b1-
: VTh
:)8 + 4 ( 10 5 = I )5 01( 5 = I = A 21 21
Va :
4 Va = 10 I 5 4 Va = 10 12 Va = 8.33V
a ) a 5V Va :8 Va = 5 + I 8 8 Va = 5 + 12 Va = 5 + 3.33
8.33V
Va . RTh ):(Short RTh = Rab :2-
:
RTh:= RTh = Rab
)8 4 ( )8 + 4 (
= 2.66
:
3-
a,b:= I ab VTh 33.8 = = 0.96 A )6 + 66.2( RTh + 6
)2(: : : : 2 E 1 E :
Iab:+ 4 = RT = 1IT 1 I ab )6 8( = 7.43 )6 + 8(
01 = 1.345 A 34.7 8 = 1.345 = 0.77 A 8 +6
: 1 E 2 E :
2 Iab:+ 8 = RT = IT 2 I ab )4 6 ( = 10 .4 )6 + 4 (
5 = 0.48 A 4. 01 4 = 0.48 = 0.192 A 4 +6
: ab :I ab = 0.77 + 0.192 = 0.962 A
)3(: RL : )1()2(
12K, 8K 2 10 I RL = 2 = mA 3 10 + 20
)1(
:10K
: RL VTh :
VTh = 2mA 10 K = 20V
: :
RTh:RTh = 10 +12 = 22 K
: :
:= I = I VTh 02 = RTh + R 22 K + 8 K 02 2 = mA 3 30 K
.
)4(: : 1- RL D, C 2- RL
RL D,C VTh: KVLVTh = VC V D R3 4 R Vth = R + R VS R + R 3 2 4 1
VS
:
VT h = VC VD 680 560 Vt h = 2 4 42 + + 086033 065086 2 3.5 8 3
8.0 1 8 5 1.6 1 = {VT h = V
=0 RTh C, D
RTh:= RTh 3R1 R 4R2 R + 4R1 + R3 R2 + R
330 x680 680 x560 = + 330 + 680 680 + 560 RTh = 529 .27
: :
C, D := I CD VTh 23.5 = = 3.5mA 0001 + 72. 926 RTh + R L
)5(:
Rab VTh : : 6VV Th =V6 =V4 K
1.4K
4K // 6K = 2.4K :
= VTh
)(6 x 2.4 K = 4.5V ) (2.4 K + 0.8 K
: 10V
V Th =V6 K
6K//0.8K = 0.706K= V Th )(10 0.706 K = 1.5V ) (0.706 K + 4 KV Th
, V Th
:
VTh =V Th V Th = 4.5 1.5 = 3V
RTh
0.8 K// 4 K// 6 K = 0.6 K RTh = 0.6 K+1.4 K = 2 K
:
HW : 1-
2-
3-
4- 6
5- R
: Norton's Theorem , RN . IN :
:
: : RL RN RTh=RN IN short circuit . . )1(: : RL
: 1-
RN
2-
RN=3//6 = 2
3- b, a a, b 6 ohm short circuit :
= IN
9V = 3A 3
)2(: 9 :
R N = 5 + 4 = 9
4 :
= IN
)( 5 10 A )( 5 + 4
= 5.556 A
:
9 := I 9 ohm )9 655.5( = 2.778 A )9 + 9(
)2(: a,b :
: RN
R N = 6// 4 = RN )4 6 ( = 2 .4 )4 + 6 (
: : : 7V short 6
= IN
7V = 1.75 A 4
: 8A
4 , 6 short circuitI N = 8A
:I N = I N I N = 8 1.75 = 6.25 A
.
HW 1- :
2- :
