Solving RC Circuit Voltage: Find Vn

Click For Summary

Discussion Overview

The discussion revolves around finding the voltage Vn in a given RC circuit. Participants explore various methods for solving the circuit, including the use of Thevenin's theorem and KVL (Kirchhoff's Voltage Law). The conversation includes aspects of circuit analysis, specifically focusing on capacitive voltage dividers and the effects of ideal voltage sources.

Discussion Character

  • Homework-related
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant suggests that C12 and C2G function as capacitive voltage dividers but expresses uncertainty about how to account for the resistor in parallel with C2G.
  • Another participant notes that there are at least three mathematically distinct approaches to solving the problem and asks which technique should be used.
  • A different reply indicates a preference for using KVL as a solution technique.
  • One participant argues that if V1 is an ideal source, then C1g is irrelevant, except for the current it draws from the voltage source, and proposes removing the load resistor to find the Thevenin equivalent of the circuit.
  • The same participant later expresses satisfaction with the solution after considering the implications of ignoring C1g.

Areas of Agreement / Disagreement

Participants express differing views on the relevance of certain components in the circuit and the methods to solve for Vn. There is no consensus on a single approach, and multiple competing views remain regarding the best technique to use.

Contextual Notes

Participants mention frequency dependence of the Thevenin voltage and the implications of ideal sources, but these aspects remain unresolved in terms of their impact on the overall solution.

likephysics
Messages
638
Reaction score
4

Homework Statement


Find Vn in the attached ckt.


Homework Equations





The Attempt at a Solution


C12 & C2G act as capacitive voltage dividers. But I don't know how to account for R in parallel with C2G.
 

Attachments

  • ckt.png
    ckt.png
    4.3 KB · Views: 521
Physics news on Phys.org
There are at least three mathematically distinct approaches to solving this. What technique are you supposed to use?
 
Antiphon said:
There are at least three mathematically distinct approaches to solving this. What technique are you supposed to use?

Any technique that works.
I'd prefer KVL.
 
Anyone?
 
If V1 is an ideal source, then C1g is irrelevant (except for the added current it will draw from the voltage source, it won't have any effect on the voltage delivered to the remainder of the circuit).

Why not remove the load resistor and determine the Thevenin equivalent of the rest? When you then add back the load you'll have a voltage supply and RC voltage divider to analyze (note that the Thevenin voltage will be frequency dependent unless V1 has a given fixed frequency).
 
gneill said:
If V1 is an ideal source, then C1g is irrelevant (except for the added current it will draw from the voltage source, it won't have any effect on the voltage delivered to the remainder of the circuit).

Why not remove the load resistor and determine the Thevenin equivalent of the rest? When you then add back the load you'll have a voltage supply and RC voltage divider to analyze (note that the Thevenin voltage will be frequency dependent unless V1 has a given fixed frequency).
Thanks. I got it. It's so simple, if C1g is ignored.
 

Similar threads

Engineering Intro to Power Systems: AC RLC circuit voltage calculations
  • · Replies 17 ·
Replies
17
Views
3K
Calculating Current in a Series RC Circuit
  • · Replies 4 ·
Replies
4
Views
3K
Engineering Transient RC Circuit (got answer in s but not in t-domain)
  • · Replies 2 ·
Replies
2
Views
2K
RC time constant problem — confusing problem statement
  • · Replies 3 ·
Replies
3
Views
2K
Engineering Why are the voltages calculated in this way? (CE BJT Amp circuit)
  • · Replies 8 ·
Replies
8
Views
2K
Engineering Circuit theory: capacitor energy storage and discharging/charging times?
  • · Replies 10 ·
Replies
10
Views
3K
What is the Voltage on C1/C2 after the switch closes?
  • · Replies 11 ·
Replies
11
Views
3K
Engineering What is the Time Constant for an RLC Circuit?
  • · Replies 9 ·
Replies
9
Views
12K
Engineering Analyzing the inductor current in the circuit
  • · Replies 1 ·
Replies
1
Views
2K
What is the gain error for this opamp driven by a voltage
  • · Replies 18 ·
Replies
18
Views
3K