How to tell if the components are in parallel or series

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Discussion Overview

The discussion revolves around understanding the configuration of components in a notch filter circuit, specifically whether the inductor and capacitor are in series or parallel, and how the resistor interacts with them. The focus is on reading circuit diagrams correctly to derive the impedance of the filter.

Discussion Character

  • Homework-related
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses uncertainty about how to read the circuit diagram and whether the inductor and capacitor should be treated as in series or parallel.
  • Another participant suggests that the circuit's impedance may depend on the range of frequencies the notch filter is designed to stop.
  • A participant outlines rules for determining series and parallel configurations, noting that series elements are connected at one end and have the same current, while parallel elements are connected at both ends and have the same voltage.
  • One participant asserts that the inductor and capacitor are connected at one end, indicating they are in series.
  • Another participant agrees that the three elements are in series and suggests marking input and output signals for clarity.
  • A participant acknowledges confusion due to the arrangement of variables in formulas that appeared to suggest a parallel configuration, clarifying that the arrangement was misleading.

Areas of Agreement / Disagreement

There is no clear consensus on the configuration of the components, as some participants assert they are in series while others express uncertainty about the implications of adding a load that could create a parallel connection. The discussion remains unresolved regarding the exact relationships between the components.

Contextual Notes

Participants express varying levels of experience with reading circuit diagrams, which may affect their interpretations. The discussion includes references to specific circuit configurations and the implications for impedance calculations, but these are not universally agreed upon.

Emspak
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Homework Statement



I need to work out the impedance of this notch filter, and what I really need is to know how to read the diagram, because if I can do that the rest isn't so hard. The diagram looks like this (I don't know if this uploaded right)

So really, all I am trying to do is tell if the inductor and capacitor should be considered in series or parallel, and if the resistor should be trated as in series with another "resistor" (the parallel sum of the inductor and capacitor) or if I should treat the resistor as in parallel with both the inductor and capacitor. Reading diagrams is elementary I know but sometimes a little explanation goes a long way, and I suspect that I should treat the inductor and capacitor as a mini-series in parallel with the resistor but I wanted to make sure.

I don't want the answer or anything, jut a note as to where to get the ball rolling.
 

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Doesn't the circuit (for a lack of better word) or the path taken by the charge change based on the impedance of the filter?
 
ShawK said:
Doesn't the circuit (for a lack of better word) or the path taken by the charge change based on the impedance of the filter?

I am honestly not sure, I was just told to find the impedance. I have zero idea of what you mean here.
 
A notch filter is a bandstop filter that stops certain frequencies while letting others pass. I have a feeling the impedance is a direct function of the range of frequencies it stops. And this range should be fairly easy to find although I forgot the exact formula
 
ShawK said:
A notch filter is a bandstop filter that stops certain frequencies while letting others pass. I have a feeling the impedance is a direct function of the range of frequencies it stops. And this range should be fairly easy to find although I forgot the exact formula
I get what a notch filter does. That isn't the problem. I need to be able to read the diagram is all, that's what I am asking so I can do the derivation correctly. I am trying to discover if I am reading it correctly or not! I don't have much experience doing it which is why I asked the question.
 
I do follow certain rules in order to check whether elements are in series or parallel.

For elements to be in series:-

If two elements are connected at only one end.
Current flowing in elements must be same and their voltage drops different(depending on resister values).

For elements to be in parallel:-

If two elements are connected to each other by both ends.
Voltage across both the elements is same and their currents different (depending on resistance values).
 
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In your circuit inductor and capacitor are connected at one end so they are in series.
 
Emspak said:

Homework Statement



I need to work out the impedance of this notch filter, and what I really need is to know how to read the diagram, because if I can do that the rest isn't so hard. The diagram looks like this (I don't know if this uploaded right)

So really, all I am trying to do is tell if the inductor and capacitor should be considered in series or parallel, and if the resistor should be trated as in series with another "resistor" (the parallel sum of the inductor and capacitor) or if I should treat the resistor as in parallel with both the inductor and capacitor. Reading diagrams is elementary I know but sometimes a little explanation goes a long way, and I suspect that I should treat the inductor and capacitor as a mini-series in parallel with the resistor but I wanted to make sure.

I don't want the answer or anything, jut a note as to where to get the ball rolling.
The 3 elements are all in series. It would help you to see how this works if you were to mark the input and output signals of this filter showing how it is used.
 
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@lazyaditya and NascentOxygen -- thanks, that is what I was trying to verify. Input is on the left, BTW, and output is on the right. The reason I was getting confused was when I looked up the actual formulas they looked as though the elements were in parallel; they weren't it was just the way they'd arranged the variables. (Some were fractions). Now that I know that the whole thing is simpler.

@lazyaditya I suspected that the "both ends" rule applied here but I wasn't sure because if you connect a load that is in parallel with the inductor and the capacitor. So it looks like a parallel connection from that point of view.
 

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