Transcript Document

ADDITIONAL ANALYSIS TECHNIQUES
LEARNING GOALS
APPLY SUPERPOSITION
We discuss some implications of the superposition property in
linear circuits
DEVELOP THEVENIN’S AND NORTON’S THEOREMS
These are two very powerful analysis tools that allow us to
focus on parts of a circuit and hide away unnecessary complexities
THE METHODS OF NODE AND LOOP ANALYSIS PROVIDE POWERFUL TOOLS TO
DETERMINE THE BEHAVIOR OF EVERY COMPONENT IN A CIRCUIT
In this section we develop additional techniques that simplify
the analysis of some circuits.
Source Superposition
This technique is a direct application of
linearity.
It is normally useful when the circuit has only
a few sources.
LEARNING EXAMPLE
Compute V0 using source superposition
We set to zero the voltage source
Current division
Ohm’s law
Now we set to zero the current source
Voltage Divider
 2[V ]
6k
3V
V0"
V0  V0'  V0"  6[V ]
+
-
3k
LEARNING EXAMPLE
Compute V0 using source superposition
We must be able to solve each circuit in a very
efficient manner!!!
If V1 is known then V’o is obtained using a voltage divider
V1 can be obtained by series parallel reduction and divider
Set to zero current source

+
-
V1
V1
_

Set to zero voltage source
6k
4k||8k
V1 
2k
V1
_
8/3
(6)
2  8/3
V'0
_
2k
VO' 
6k
18
V1  [V ]
6k  2k
7
The current I2 can be obtained using a current divider
and V”o using Ohm’s law
I2
2k||4k
2mA
+
I2
6k
V"0
I2 
2k  (2k || 4k )
(2)mA
2k  6k  (2k || 4k )
VO"  6kI 2
VO  VO'  VO"
2k
_
WHEN IN DOUBT… REDRAW!
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+
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