Practical Diagrammatic Electrical Circuit Theory
Transcript of Practical Diagrammatic Electrical Circuit Theory
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Practical Diagrammatic
Electrical Circuit Theory
Guillaume Boisseau and Pawe l Sobocinski
July 16, 2021
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Applied applied category theory
We already know we can analyze electrical circuits using diagrams.
Q: is this practical? A: yes!
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Graphical Linear Algebra
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Background: Graphical Linear Algebra
Idea: we write affine equations using diagrams.
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GLA: building blocks
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GLA: composing
Composition works by identifying connected variables.
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GLA: reasoning
We can prove any equivalence.
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Electrical circuits
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Electrical circuits
Ohm’s law:
Diagrammatically:
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Electrical circuits: building blocks
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Electrical circuits: composition
The behavior of a circuit is made by plugging together the
behavior of its elements.
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Impedance boxes
Notice a pattern: write for the circuit .
Then , and .
This generalizes complex impedance.
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Impedance boxes
Notice a pattern: write for the circuit .
Then , and .
This generalizes complex impedance.
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Closed circuits
Problem: a closed circuit has a trivial equation
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Closed circuits
If only we could tap a wire
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Closed circuits
Solution: add a measuring element
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Closed circuits
Solution: add a measuring element
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Closed circuits
Solution: add a measuring element
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Let’s prove some theorems!
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Conservation of currents
Currents entering a circuit C must sum to zero.
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Conservation of currents
Currents entering a circuit C must sum to zero.
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Conservation of currents
Currents entering a circuit C must sum to zero.
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Conservation of currents: proof
Proof: by induction.
Base case:
Inductive case:
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Superposition theorem
The behavior of a circuit is linear in its sources.
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Conclusion
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Conclusion
• This is a credible alternative to standard linear algebra.
• Diagrams are good at inductive & topological properties.
• Diagrams are extensible.
• Diagrams are truer to the model because relational.
• This is fun, I want to see more of that.
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Questions?