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Electrical Fundamentals 1 - P.Sheldon
Complex Circuit Redraws - Sample Solution
Figure 1
Figure 2
The first step is to redraw the circuit so that it is
evident which components are in parallel and
which are in series for further simplification of
the circuit.
Figure 2
Figure 3
The second step is to simplify all series
components within single parallel branches.
RA = R2 + R3
Figure 3
Electronic Engineering Technician Programme - ef1-complex circuit redraw problems
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Electrical Fundamentals 1 - P.Sheldon
Figure 4
The third step is to simplify all possible parallel
branches
RB = RA   R4
Figure 4
Figure 5
Finally simplify the final series components for
RT.
RT = R1 + RB + R5
You must repeat these steps as many times as
necessary to complete the simplification of the
circuit.
Figure 5
Equations
RA = R2 + R3
RB = RA   R4
RT = R1 + RB + R5
Mathematically the circuit looks like this
RT = R1 + ((R2 + R3)   R4) + R5
Electronic Engineering Technician Programme - ef1-complex circuit redraw problems
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Electrical Fundamentals 1 - P.Sheldon
Complex Circuit Redraws - Problems
Set #1 R1 = 1kΩ, R2 = 4k7Ω, R3 = 6k8Ω, R4 = 10kΩ, R5 = 2k2Ω, R6 = 1k8Ω, R7 = 3k3Ω, R8 = 5.6kΩ
and R9 = 1k2Ω.
Set #2 R1 = 2k2Ω, R2 = 12kΩ, R3 = 5k6Ω, R4 = 3k3Ω, R5 = 4k7Ω, R6 = 10kΩ, R7 = 1k2Ω, R8 = 3k9Ω
and R9 = 9k1Ω.
Set #3 R1 = 2k7Ω, R2 = 3k3Ω, R3 = 1k8Ω, R4 = 3k9Ω, R5 = 1k2Ω, R6 = 1k5Ω, R7 = 470R, R8 = 680R
and R9 = 1kΩ.
Solve for RT in the following 10 circuits using the above sets of values.
Figure 1
Figure 3
Figure 5
Figure 2
Figure 4
Figure 6
Electronic Engineering Technician Programme - ef1-complex circuit redraw problems
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Electrical Fundamentals 1 - P.Sheldon
Figure 7
Figure 8
Figure 9
Figure 10
Electronic Engineering Technician Programme - ef1-complex circuit redraw problems
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Electrical Fundamentals 1 - P.Sheldon
Complex Circuit Redraws - Answers
Set #1
(unit)
1
2
3
4
5
6
7
8
9
10
Figure #
Set #2
(unit)
1
2
3
4
5
6
7
8
9
10
Figure #
Set #3
(unit)
1
2
3
4
5
6
7
8
9
10
Figure #
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
RT
(Ω)
3k78
7k62
13k8
8k55
7k08
5k87
6k53
16k
14k2
6k83
RT
(Ω)
6k02
7k46
9k32
9k68
8k64
7k14
9k74
14k
23k7
5k73
RT
(Ω)
3k86
3k29
7k76
6k11
3k92
3k39
5k16
8k96
6k96
5k03
Electronic Engineering Technician Programme - ef1-complex circuit redraw problems
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