lecture 6: thevenin and norton equivalents, maximum power transfer, & superposition nilsson...
TRANSCRIPT
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Lecture 6:Thevenin and Norton Equivalents,Maximum Power Transfer, &SuperpositionNilsson & Riedel 4.10-4.13
ENG17 (Sec. 2): Circuits I
Spring 2014
April 17, 2014
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Overview
• Thevenin Equivalent• Norton Equivalent• Special Cases• Maximum Power
Transfer• Superposition
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Thevenin Equivalent Circuit
• Independent voltage source in series with resistor• Provides simplified equivalence to more complex circuit
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Finding Thevenin Equivalent
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Overview
• Thevenin Equivalent• Norton Equivalent• Special Cases• Maximum Power
Transfer• Superposition
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Norton Equivalent Circuit
• Independent current source in parallel with resistor• Provides simplified equivalence to more complex circuit• Relates to Thevenin Equivalent (source transformation)
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Finding Norton Equivalent
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Overview
• Thevenin Equivalent• Norton Equivalent• Special Cases• Maximum Power
Transfer• Superposition
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With Dependent Source
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Alternate Method
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Overview
• Thevenin Equivalent• Norton Equivalent• Special Cases• Maximum Power
Transfer• Superposition
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Power Transfer
• Two issues:– Efficiency of Power Transfer– Amount of Power Transfer
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Maximum Power Transfer
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Example
• Find value of RL that results in maximum power transfer.
• Use Thevenin Equivalent circuit.
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Overview
• Thevenin Equivalent• Norton Equivalent• Special Cases• Maximum Power
Transfer• Superposition
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Superposition
• Applies to linear system• Defined: when linear system is excited by >1
independent energy sources, the total response is the sum of individual responses.
• Clarified– Deactivate 1st source, find response from 2nd
source– Deactivate 2nd source, find response from 1st
source– Add these responses
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In practice
• May not help so much right now…
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w/Dependent Sources
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Overview
• Thevenin Equivalent• Norton Equivalent• Special Cases• Maximum Power
Transfer• Superposition