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Experiment No.3
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Any linear bilateral network may be reduced to a simplified
two-terminal
circuit consisting of a single voltage source in series with a
single resistor.
A
VTH
RTH
B
RL
IL
V2
I2R2R1
I1
V1 RL
IL
To find current through RL,using Thevenins theorem.
(V1=4V; V2=6V; R1=1K; R2=10K; RL=15K)
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R1 R2
RTH
Step 1: To find RTH
R1 R2I
V2V1 VTH or VOC
A
B
C
DE
F
Step 2:To find VTHor VOCIn a closed circuit ABCDEFA, apply
KVL
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Now consider the loop ABEFA, apply KVL
RL
IL
ILVTH
RTH
Step 3:To find IL
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Any two terminals of a network containing linear, passive and
active
elements may be replaced by an equivalent current source IN in
parallel with
the resistance RN, Where IN is the current flowing through a
short circuit
placed across the terminals AB and RN is the equivalent
resistance of the
network as seen from the two terminals with all independent
sources
suppressed.
RL
IL
IN
RN
A
B
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V2
I2R2R1
I1
V1 RL
IL
To find, current through RLusing Nortons theorem.(V1=4V; V2=6V;
R1=1K; R2=10K; RL=15K)
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R1 R2
RN
Step 1: To find RN
A
B
C
DE
F
R1 R2I1
V2V1 ISC or IN
I2Step 2:To find ISCor IN
(INor ISC=I1+I2)
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In a closed circuit ABCEFA, apply KVL
Solving for equation (1) and (2),
I1= 3.9954mA ; I2=0.59954mA
IN=I1+I2=4.59494mA
RL
IL
IN
RNH
A
B
Step 3:To find IL
Using current division technique
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Experiment No.4
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The superposition principle states that thevoltage across (or
current through)
an element in a linear bilateral circuit is the algebraic sum of
the voltages
across (or currents through) that element due to each
independent source
acting alone.
IL
V2V1
R1 R2I
2
I1
R3
IL
V1
R1 R2IT
V2ShortedR3
(V1=4V; V2=6V; R1=1K; R2=10K; R3=15K)
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IL
V2V1
Shorted
R1 R2IT
R3
IL= I
L'+I
L'' = 0.2284mA + 0.034286mA = 0.262686mA
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IL
V2V1
R1R2I2I1
A
R3RPS
RPS
AA
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Experiment No.4
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In D.C circuits
Maximum power is transferred from a source to the load when
the
load resistance is made equal to the resistance of the network
as viewed from
the load terminals with load removed and all the sources
replaced by their
internal resistances. (Theveninsresistance)
RL=R
TH
RL
D.C CIRCUIT RL
RTH
VOC
A
B
IL
The current supplied to RLis given by LTH
OC
L
RR
VI
Power is delivered to RLis LLTH
OC
LLLL R
RR
VPRIP
2
2
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Maximum power is transferred from a source to the load when
the
impedance of the load terminal is the complex conjugate of
source
impedance measured by looking back into the terminals of the
network.
(Theveninsimpedance)
ZL=Z
TH*
RL
IL
VL
RTH
RPS
A
V
RL Ohms
P
Watts
Pmax
Maximum
0
