Parallel Resonance
Dr. Mohamed Refky Amin
Electronics and Electrical Communications Engineering Department (EECE)
Cairo University
http://scholar.cu.edu.eg/refky/
OUTLINE
• Previously on ELC N112
• Analysis of Parallel Resonance Circuits
• Quality Factor of a Coil
• Solved Examples
2Dr. Mohamed Refky
Previously on ELC N112
In physics, resonance is the tendency of a system to oscillate with
greater amplitude at some frequencies than at others.
Frequency at which the response amplitude is a maximum is
known as the system's resonant frequency, or resonance frequency
Dr. Mohamed Refky
Definition of Resonance
Previously on ELC N112
Series resonance Parallel resonance
Dr. Mohamed Refky
Previously on ELC N112
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Current Expression in Series Resonance
Previously on ELC N112
Dr. Mohamed Refky
Previously on ELC N112
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Previously on ELC N112
Resonance at
-
in rad/s in Hz
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Parallel Resonance
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Ideal Parallel Circuit
Parallel Resonance
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In parallel circuits, at resonance,
the capacitor and the coil are
replaced by an Open Circuit.
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Ideal Parallel Circuit
Parallel Resonance
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Quality Factor of a Real Coil
Parallel Resonance
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Parallel Resonance
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The Equivalent All-Parallel Circuit
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Parallel Resonance
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The Equivalent All-Parallel Circuit
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Parallel Resonance
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The Equivalent All-Parallel Circuit
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Parallel Resonance
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The Equivalent All-Parallel Circuit
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Parallel Resonance
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The Equivalent All-Parallel Circuit
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Parallel Resonance
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Parallel Resonance
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• Impedance & voltage in terms of quality factor
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Parallel Resonance
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Parallel Resonance
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Parallel Resonance
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Bandwidth and Cut-off Frequencies
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Parallel Resonance
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Bandwidth and Cut-off Frequencies
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Parallel Resonance
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Bandwidth and Cut-off Frequencies
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Bandwidth and Cut-off Frequencies
a b c
1
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Bandwidth and Cut-off Frequencies
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Parallel Resonance
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Parallel Resonance
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In general:
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Resonance at
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Parallel Resonance
Parallel Resonance
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Example (1)
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Example (2)
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Example (3)
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Example (4)
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