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schematic

simulate this circuit – Schematic created using CircuitLab

As the schematic shows, there is a voltage source in between capacitor and inductor. Is it a valid Parallel RLC circuit. For example: can we say that we can use the standard equations like:

  • Alpha = 1 / ( 2 * R * C)
  • W0^2 = 1 / (L * C)

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    \$\begingroup\$ Where are you applying stimulus? At the location of V1, or across the whole network? \$\endgroup\$
    – The Photon
    Commented Oct 3, 2015 at 3:42
  • \$\begingroup\$ @ThePhoton I'm not quite sure on what stimulus means in this case, as I am just starting to learn electronics and I came across a circuit that is similar to this schematic. My original instinct was that it is neither parallel nor series. \$\endgroup\$ Commented Oct 3, 2015 at 3:56
  • \$\begingroup\$ You are trying to make a resonant circuit. It will resonate in response to some stimulus. Where do you intend to apply the stimulus? \$\endgroup\$
    – The Photon
    Commented Oct 3, 2015 at 3:59
  • \$\begingroup\$ Then, I would say it would be at the location of V1. \$\endgroup\$ Commented Oct 3, 2015 at 4:05

1 Answer 1

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In comments, you say you'll apply a stimulus at the location of V1. In that case, you can redraw the circuit like this:

schematic

simulate this circuit – Schematic created using CircuitLab

You can see that as far as this stimulus is concerned, the L and C elements are not in parallel. Nor are they strictly in series, since not all current through the C element also flows through the L element.

You can also see immediately that this circuit has some behavior that doesn't match either a parallel or series RLC circuit. For example, the impedance goes to inifinity (like a series RLC circuit) at \$\omega=0\$, but it goes to R (instead of to infinity again) in the limit as \$\omega\to\infty\$.

Short answer: This circuit does not behave like either a series or parallel RLC circuit.

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  • \$\begingroup\$ Would it still be same case if the stimulus was applied across the whole circuit? \$\endgroup\$ Commented Oct 3, 2015 at 17:57
  • \$\begingroup\$ The DC source would have no effect (assuming an ideal source, real world devices might be different) on the ac behavior, so if your stimulus between ground and the node where V1, L1, and R1 meet, then yes, the AC behavior would be like a parallel RLC circuit. \$\endgroup\$
    – The Photon
    Commented Oct 3, 2015 at 21:36

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