How to Calculate RLC Phase Angle in Multisim

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Discussion Overview

The discussion revolves around calculating the phase angle in an RLC circuit using Multisim, particularly focusing on the phase angles across capacitors and inductors. Participants share their experiences with a lab assignment and seek clarification on measuring phase angles and interpreting oscilloscope readings.

Discussion Character

  • Homework-related
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes their lab setup in Multisim and expresses uncertainty about calculating the phase angle across the capacitor and inductor, noting that they have the measured values from class.
  • Another participant suggests measuring the distance between the source wave and the component wave and proposes using the equation tan-1(dV/R) for calculating phase angles.
  • A different participant indicates that the provided equation is for the phase of the entire circuit and suggests that a "phase difference" might be what is needed, referencing the equation φ = ω ΔT = 2 π f ΔT.
  • One participant mentions issues with oscilloscope readings not matching lab measurements and indicates a need to adjust the placement of a resistor to obtain accurate readings.
  • Another participant notes that the oscilloscope is monitoring the capacitor voltage and observes that this voltage lags the signal voltage.

Areas of Agreement / Disagreement

Participants express uncertainty about the correct method for calculating phase angles, with multiple approaches and interpretations presented. There is no consensus on the best way to proceed with the calculations or the interpretation of oscilloscope data.

Contextual Notes

Participants have not fully resolved the application of phase angle equations, and there are indications of missing assumptions regarding circuit configurations and measurement techniques. The discussion reflects varying levels of understanding of phase relationships in RLC circuits.

dwn
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Homework Statement


This is actually a lab I'm performing on Multisim. I've recreated a circuit that I build in lab class , but I'm not getting the output I need. I am trying to calculate the V and phase angle across each component. I already have the measurements found form the class lab. In addition to the oscilloscope terminal B not working, I'm not sure how to calculate the phase angle across the cap and inductor.

I know that each angle is -90 for cap and +90 for inductor.

Homework Equations


See images
RLC.png
RLC phase angle.png


The Attempt at a Solution



Measured values, but not sure how to apply to phase angle equation to find capacitor and inductor phase angles.
 
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Nevermind the multisim question, I figured out what I was doing wrong. As far as calculating the phase angles: do I measure the distance between the source wave and the component wave (wave/division) then take the tan-1(dV/R)?
 
but not sure how to apply to phase angle equation to find capacitor and inductor phase angles.

The equation you have been given is for the phase of the entire circuit.

I'm not sure, but you may be looking for a "phase difference". In that case ##\phi = \omega \Delta T = 2 \pi f \Delta T## should be all you need.
 
My second port is no longer flat-lining, and I know I have to move the placement of the resistor in the circuit in order to get a reading of it on the oscilliscope, but the scope doesn't match my Vr measurement from lab, instead its looks closer to what I got for the Vcap measure. Could someone please explain this to me?
 

Attachments

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You have B monitoring the capacitor voltage (between the capacitor and earth), and the display shows this voltage lagging the signal voltage.
 

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