Fourier Series Week 7 Lab:
This week’s lab is based on the application of Fourier analysis of an inductive circuit in Multisim. You will learn to utilize Multisim to measure the unknown frequencies in the spectrum.
 Analyze the circuit and determine the output voltage ‘Vout’ of an Op Amp circuit, use a frequency of 150Hz.
 Construct Figure 18.15 in Multisim and perform the Fourier analysis.
 Run simulation to measure the frequency and the voltage gain of the amplifier.
 Change the input voltage magnitude to the values from the table and run the Fourier analysis again.
 Record the frequencies visible in the frequency spectrum in the table.
 Take the screen capture for the measurements for ‘Vout’.
Vin 
Calculated ‘Vout’ (pk –pk) 
Measured ‘Vout’ (pk –pk) 
Identified frequencies in the spectrum 
1V 

1.5V 

2V 

3V 
 Answer the following questions:
 Explain the effect of input voltage on the output voltage of the Op Amp.
 Express the voltage gain of an amplifier in terms of R1 and R2 and then compute it.
 From your measurements, what happens to the output when the magnitude of input voltage is increased?
 What is the effect of input voltage on the frequency spectrum? Explain with the help of measurement results and screenshots.
 Create a new word document called “Lab7_StudentID.docx” with your GID substituted into the file name.
 Save the analysis from step 2 and simulation results from step 3 along with the table and screen captures of all the measurements. Make sure to answer the questions in step 4.
 Upload file “Lab7_StudentID”.
Fourier Transform Week 8 Lab:
This week’s lab is based on the application of Fourier analysis of an RL circuit in Multisim.
 Watch video lecture entitled “Module 8 – SteadyState RL Circuit in Multisim”.
 Construct Figure 18.44 in Multisim with Vi(t) set to the pulse train as below.
 Run simulation to perform Fourier and Transient Analysis to measure the output voltage ‘V_{c}(t)’.
 Record the voltage ‘V_{c} (t)’ and the current ‘I’ through the capacitor in the table below.
 Take the screen capture for the measurements for ‘V_{c} (t)’ and line spectrum from Fourier analysis.
 Add 5% tolerances to resistor and inductor and repeat step 3.
Measured ‘V_{c} (t)’ 
Measured current ‘I’ 

Without Tolerances 

With Tolerances 
 Answer the following questions:
 Explain the effect of tolerance on output voltage ‘V_{c} (t)’.
 Identify the frequencies and trace the frequency spectrum for the voltage ‘V_{c} (t)’.
 How does tolerance effect the frequencies in the spectrum and the output voltage? Explain with the help of measurement results and screenshots.
 Create a new word document called “Lab8_StudentID.docx” with your GID substituted into the file name.
 Save the simulation results from step 3 and 4 along with the table and screen captures of all the measurements. Make sure to answer the questions in step 5.
 Upload file “Lab8_StudentID.docx”.