EE Electronics fundamentals/Lecture Basic Resistive Circuit Analysis

Kirchhoff's voltage law

Sum of voltages between the start and end of circuits is 0.

 

V0 = V1 + V2

Kirchhoff's current law

Currents in point are balanced. Sum of currents is 0.

 

I1+I3=I2

Mesh method

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based on KVL

  1. Choose the reference point
  2. Walk through this loop by labeling voltages(even if undefined)
  3. Construct equation
  4. Solve equation

*if more loops, then possible to create the system of equation

 
Example of circuit

Whole resistance:  
Whole current:  

 
 
*if any from this resistors is undefined, we can solve this equation


In general we can use also this equation:
 

Signs for elements mirroring the logic of KVL.

Node method

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Example of circuit
  1. Choose node
  2. Label currents
  3. Construct equation
  4. Solve equation

 

 

 
 


Also possible to create systems of equations for complex circuits.

Conversions

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https://en.wikipedia.org/wiki/Y-%CE%94_transform

References

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Book about circuit analyses: https://archive.org/details/engineeringcircu0000hayt_n1c5/

More about KVL on allaboutcircuits.com

More about KCL on allaboutcircuits.com

More about conversions on allaboutcircuits.com