Circuit Analysis III
description
Transcript of Circuit Analysis III
Circuit Analysis IIISection 06
Multiple Sources What if more than one source in the circuit?
How to solve for all currents?
Slide 2
KVL and KCL (nodes, loops, planner circuit, voltage drop)
then what?
To solve for all currents and volts in a circuit:
KVL: Kirchhoff’s Voltage Law the algebraic sum of voltages in a loop is zero
KCL: Kirchhoff’s Current Law the algebraic sum of currents into a node is zero
Slide 3
Circuit Analysis
1. count nodes minus one (possible ground)2. mark a current for each branch
name and direction
3. write KCL equations for each node4. count the loops5. write the KVL equations for each loop6. solve for all unknowns
Slide 4
Example
Slide 5
1
0
+ -
+++
-
-
-1 2
Example
Slide 6
1
0
+ -
+++
-
-
-
321: IIIKCL
01245
0565.1:
223
31
III
IIKVL mAI
mAI
mAI
5.116
4.36
9.152
3
2
1
Example
Slide 7
8 branches 8 currents I1..I8 8 equations4 nodes 4 eqs4 loops 4 eqs
Impedance treat all passive components as resistors
but with complex resistances
Electrical Engineering Umm Al-Qura University Slide 8
Impedance What is the impedance of a 10mF capacitor
when operated at 60Hz?
What is the impedance of a 2mH inductor when operated at 60Hz?
Electrical Engineering Umm Al-Qura University Slide 9
25.2651010602 6 j
jwCj
ZC
754.0102602 3 jjjwLZL
Example
Electrical Engineering Umm Al-Qura University Slide 10
Solution
Electrical Engineering Umm Al-Qura University Slide 11
321: IIIKCL
010003.11531
0531000,20110:
223
31
IIjIj
IjIKVL
Simulation Solution
Electrical Engineering Umm Al-Qura University Slide 12
Current Source Voltage Source
Generates constant volt regardless of the load
Current SourceGenerates constant current regardless of the
load
Electrical Engineering Umm Al-Qura University Slide 13
KVL & KCL
Electrical Engineering Umm Al-Qura University Slide 14
Vv 501051
Vv 751552
vx
+
-
21 vvvx
Example
Electrical Engineering Umm Al-Qura University Slide 15
321: IIIKCL
0105
05320:
23
31
ivII
IIKVL
Vv
AI
AI
AI
i 125.48
625.3
3
625.0
3
2
1
AIIS 3: 2
Power Power = rate of energy transfer
measured in Watts (W)
Electrical Engineering Umm Al-Qura University Slide 16
VIP
RIVIP 2
RV
VIP2
Process Check Solve the circuit shown and find the power
consumption of each component
Electrical Engineering Umm Al-Qura University Slide 17
Solution (1)
Electrical Engineering Umm Al-Qura University Slide 18
Akk
I
4001510
10
mWRIP 6.1101010400 3261
21
mWRIP 4.2101510400 3262
22
Solution (2)
Electrical Engineering Umm Al-Qura University Slide 19
Vkk
kV
Vkk
kV
61510
1510
41510
1010
2
1
mWRV
P 6.11010
43
2
1
21
1
mWRV
P 4.21015
63
2
2
22
2
Total Power = 0
Electrical Engineering Umm Al-Qura University Slide 20
mWVIPS 41010400 6
mWPP 421 Total Power = Zero