Capacitance vs. Resistance Proof

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SUMMARY

The discussion centers on the relationship between capacitance and resistance using a wye-delta transformation to derive equivalent capacitance. The user derives the equation t = R*C, indicating that resistance (R) can be expressed in terms of capacitance (C) and time (t). However, a critical note highlights a contradiction in the assumptions made during integration, specifically regarding the constancy of voltage (V) over time. This indicates the need for careful consideration of variable voltages and currents in circuit analysis.

PREREQUISITES
  • Understanding of basic electrical engineering concepts, specifically capacitance and resistance.
  • Familiarity with wye-delta transformations in circuit analysis.
  • Knowledge of calculus, particularly integration techniques.
  • Proficiency in analyzing time-dependent electrical signals.
NEXT STEPS
  • Study the principles of wye-delta transformations in greater detail.
  • Learn about the time constant in RC circuits and its implications.
  • Explore variable voltage and current analysis in electrical circuits.
  • Investigate advanced integration techniques relevant to electrical engineering.
USEFUL FOR

Electrical engineers, circuit designers, and students studying circuit theory who are interested in the interplay between capacitance and resistance in dynamic systems.

checkmatechamp
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Can somebody confirm if this is correct? I'm trying to use a wye-delta transformation on capacitors to solve for equivalent capacitance, but to be super-precise, I want to put capacitance in terms of resistance.

I = C*(dV/dt)
V = IR, so I = V/R

V/R = C*(dV/dt)

(V*dt) = R*C* dV

Integrate both sides.

V*t = R*C*V

t = R*C which means that R = t/C

That makes sense, since people talk about a time constant, but I just want to be sure.
 
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You need to specify the circuit ...

Note:
Your integration assumes that V is a constant with time, but your first equation assumes that dV/dt is not zero, therefore V does vary with time. This is a contradiction (unless I=0). Try using lower case for variable voltages and currents.
 

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