Equivalent capacitance of an infinite system

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SUMMARY

The discussion focuses on calculating the equivalent capacitance of an infinite capacitor system between points a and b. The relationship Q=CV is established, where Q represents charge and V is the potential difference across capacitors. The user derives equations for the potential differences and attempts to express the total charge in terms of an infinite series. The key challenge identified is determining the equivalent capacitance of the right-hand portion of the circuit after dividing it along a specified line.

PREREQUISITES
  • Understanding of capacitor fundamentals, specifically the formula Q=CV.
  • Familiarity with infinite series and their convergence properties.
  • Basic circuit analysis techniques, including voltage division.
  • Knowledge of potential difference and charge relationships in capacitors.
NEXT STEPS
  • Study techniques for solving infinite series in electrical circuits.
  • Learn about the concept of equivalent capacitance in complex networks.
  • Explore advanced circuit analysis methods, such as Thevenin's and Norton's theorems.
  • Investigate the behavior of capacitors in series and parallel configurations.
USEFUL FOR

Electrical engineering students, circuit designers, and anyone interested in advanced capacitor network analysis will benefit from this discussion.

Fahamedi
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Homework Statement


Find the equivalent capacitance of the infinite system between points a and b (see figure).
Where Vi is the potential difference in the number i capacitor.

Homework Equations


Q=CV

The Attempt at a Solution


For number i capacitors we have the relations

Q_i=CV_i and Q'_i=CV'_i
\Rightarrow Q\equiv \sum_{i=0}^{\infty}(Q_i+Q'_i)=C\sum_{i=0}^{\infty}(Vi+V'i)

Now if V is the potential difference V=Va-Vb and we look at the paths in the system,

V_0+V'_0=V ; V_0+V_1+V'_1=V ; ... ; V_0+V_1+V_2+...+V_i+V'_i=V ; ...

From this I found

V'_i=V_{i+1}+V'_{i+1}

\Rightarrow Q=C\sum_{i=0}^{\infty}(V_i+V_{i+1}+V'_{i+1})

And I'm stuck here, I don't know what to do next, or should I do something different?
 

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Hint: Say you divide the circuit into two along the dotted line. What's the equivalent capacitance of the righthand portion?
 

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