Fourier Transform Lab

Fourier Transform Lab

This week’s lab is based on the application of Fourier analysis of an RL circuit in Multisim.

Construct Figure 18.44 in Multisim with Vi(t) set to the pulse train as below.

1. Run simulation to perform Fourier and Transient Analysis to measure the output voltage ‘V_c (t)’.
   1. Record the voltage ‘V_c (t)’ and the current ‘I’ through the capacitor in the table below.
   2. Take the screen capture for the measurements for ‘V_c (t)’ and line spectrum from Fourier analysis.

 

Without tolerance

With tolerance of 5%

 

2. Add 5% tolerances to resistor and inductor and repeat step 3.

	Measured ‘Vc (t)’	Measured current ‘I’
Without Tolerances	0.411231∟-91.853◦	0.645∟0.4860◦
With Tolerances	0.411231∟-91.853◦	0.645∟0.4860◦

3. Answer the following questions:
   1. Explain the effect of tolerance on output voltage ‘V_c (t)’.

Ans . Getting no effect

1. Identify the frequencies and trace the frequency spectrum for the voltage ‘V_c (t)’.
2. How does tolerance effect the frequencies in the spectrum and the output voltage? Explain with the help of measurement results and screenshots.

 

 

 

 

 

 

 

Circuit Analysis

For the circuit below, perform the following:

1. Given an AC input voltage of Vrms = 200Vrms and a sinusoidal frequency of omega = 120pi rad/sec, determine the following: ◦V1peak (peak value of AC input voltage)

◦ V1(peak-to-Vpeak )(peak to peak value of AC input voltage)

Ans   V1 =   V

◦ Frequency of input voltage V1 in Hz.

Ans  f = 60 Hz

◦ V2peak (peak value of AC output voltage)

Ans

V2 =  V1

Where

Z=

V2 =   V

◦ V2(peak-to-Vpeak )(peak to peak value of AC output voltage)

Ans

V2 =  V

◦ Frequency of output voltage V2 in Hz.

Ans f = 60Hz

2. Construct circuit in MultiSIM using calculated values for V1.
3. Capture a screenshot that shows V1 and V2 on an oscilloscope XSC1.

For V1

 

 

For V2

 

 

4. Submit calculations, MultSIM screenshot and MultiSIM circuit (.ms11) file

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

For the circuit below, perform the following:

1. Given a voltage gain of -10, determine the value of R2.

Ans1   R2 = 10 KΩ

 

2. Calculate the peak-to-peak value of Vout and rms value of Vout.

Ans2  Vout (peak-to-peak) = 2Vin X |Gain| = 20

Vout (rms) =  Vin |Gain| = 10 V

 

3. Construct circuit in MultiSIM with calculated value of R2.
4. Capture a screenshot that shows the input voltage V1 and output voltage Vout in MultiSIM with an oscilloscope XSC1

Input Voltage V1

Output Voltage V2

5. Submit calculations, MultSIM screenshot and MultiSIM circuit (.ms11) file