Laboratory Procedures

DeVry University

College of Engineering and Information Sciences

 

I.                   OBJECTIVES

 

1.      To analyze a RC Low Pass Filter using simulation and circuit measurement.

2.      To analyze a RC High Pass Filter using simulation and circuit measurement.

3.      To analyze a LC Band Pass Filter using simulation and circuit measurement.

II.        PARTS LIST

Equipment:

            IBM PC or Compatible

Function Generator

Dual Channel Oscilloscope

 

Parts:

1 – 50 Ω Resistor                     1 – 470 nF, 50 V Capacitor

1 – 330 Ω Resistor                   4 – 47 µF, 35 V Capacitor

4 – 4.7 mH Inductor                 2 – 100 µF, 25 V Capacitor

1 – 470 mH, Inductor

Software:

MultiSim 11

 

III.       PROCEDURE

A.                Simulation of RC Low Pass Filter |

1.      Enter the circuit shown in Figure 1 in MultiSim.

 

Figure 1 – Low Pass Filter

 

2.      Set the function generator voltage, V_In = 1 V_P.

3.         Simulate the circuit shown for various frequencies indicated in Table 1 below. Record the output voltage, V_Out, for each frequency and calculate the gain using the formula: 20 log(V_{Out P-P} / V_{In P-P}).

 

Frequency, Hz	VOut P-P	GaindB	Frequency, Hz	VOut P-P	GaindB
100			2000
200			4000
400			8000
800			10000
1000

 

Table 1 – Low Pass Filter Frequency Response Simulation Data

Low

4.      Determine the voltage “Gain/Loss” in dB for the frequency response plot. Plot the simulation data of on the semi-log graph sheet below. The frequency must be on the X axis and the Gain_dB on the Y–axis.

 

5.      What is the 3 dB cutoff frequency from the plot?

f_C =___________________

6.      Calculate the 3 dB Cutoff frequency using the formula: f_C = 1/(2π R C)

f_C =___________________

 

7.      Does the simulated measurement agree with the theoretical calculation?

 

Yes ______ No ______

 

 

 

B.        Simulation of RC High Pass Filter

 

1.      Enter the circuit shown in Figure 2 in MultiSim.

 

 

Figure 2 – High Pass Filter

 

2.      Set the function generator voltage, V_In = 1 V_P

 

3.      Simulate the circuit shown for various frequencies indicated in Table 2 and record the output voltage and gain.

 

Frequency, Hz	VOut P-P	GaindB	Frequency, Hz	VOut P-P	GaindB
100			2000
200			4000
400			8000
800			10000
1000

Table 2 – Low Pass Filter Frequency Response Simulation Data

 

4.      Determine the voltage “Gain/Loss” in dB for the frequency response plot. Plot the simulation data of on the semi-log graph sheet below.

 

5.      What is the 3 dB cutoff frequency from the plot?

f_C =___________________

6.      Calculate the 3 dB Cutoff frequency using the formula: f_C = 1/(2π R C)

f_C =___________________

 

7.      Does the simulated measurement agree with the theoretical calculation?

 

Yes ______ No ______

 

C.        Simulation of LC Band Pass Filter

 

1.      Enter the circuit shown in Figure 3 in MultiSim.

 

 

Figure  3 – LC Band Pass Filter

 

 

 

2.      Setup the function generator voltage, V_In = 1 V_P.

 

3.      Simulate the circuit shown for various frequencies indicated in Table 3 and record the output voltage and gain.

 

Frequency, Hz	VOut P-P	GaindB	Frequency, Hz	VOut P-P	GaindB
200			340
250			344
280			348
290			355
300			352
320			356
324			360
330

 

Table 3 – Band Pass Filter Frequency Response Simulation Data

 

4.      Determine the voltage “Gain/Loss” in dB for the frequency response plot. Plot the simulation data of on the semi-log graph sheet below.

 

 

 

 

 

 

 

 

5.      What are the 3 dB cutoff frequencies from the plot?

Upper f_C =_____________   Low f_C =_____________

 

6.      The LC band pass filter is PI- Section filter which has been designed using the website:

 

http://www.raltron.com/cust/tools/band_pass_filters.asp

 

The filter has been designed to operate at a center frequency, f_o of 340 Hz and a 3dB Bandwidth of 10% of f_o.

 

Log in to the above website; feed the data of center frequency and the bandwidth desired. Verify if the design values chosen for the lab experiment are close enough.

 

7.      What are the calculated 3 dB cutoff frequencies?

Upper f_C =_____________   Low f_C =_____________

8.      Do the simulated measurements agree with the theoretical calculations?

 

Yes ______ No ______

 

9.      Increase or decrease the center frequency by 5 and recalculate the element values. Note and record the new design parameters. What can you comment on the new design values when compared with the original values?

 

 

 

 

10.  The filter can be reconfigured to a T–type using the transformation shown below:

 

 

Some useful formulas for the Constant K type band pass filter design:
fC = Filter Center Design frequency R0 = Filter Design Impedance f1 and f2 => 3 dB cutoff frequencies, Lower & Upper.. Also,    f1 x f2 = fC2 Bandwidth = f2 – f1

Source for the above formulas: “HANDBOOK OF LINE COMMUNICATIONS”, A Royal Signals Pub., 1947.

 

Using the suggested transformation, change the original PI type filter to T-type and simulate to verify if it works as the original. Include the new filter topology below here.

 

 

 

11.  Did the filter work as the original?        YES             NO

 

D.        BreadboardConstructionof the three Filters

1.      Build the three filters simulated above on a breadboard, one at a time

 

2.      Use a Function Generator to excite the filters and check for the pass band and the cut off frequencies.

3.      Submit a photograph of each of your working circuits (online) or have your instructor sign-off each circuit (onsite).

Assignment 3: Environmental Issues and the Industrial Revolution

The Industrial Revolution, which began in the eighteenth century, has had an ongoing influence on society as well as the relationship between humans and their environment. With the onset of industrialization came the drastic increase in urbanization, setting up of factories in places which were once biomes, and the rapid development of land. All this occurred without assessing the long-term impact to the environment. Recognizing the importance of the Industrial Revolution era and the ongoing impact it has had on the environment is essential to learning how to help the environment and correct the damage of that era.

Using the readings for this module, the Argosy University online library resources, and the Internet, complete the following:

• Identify three of the most environmentally negative impacts of the Industrial Revolution and justify your choices. For example, the invention of the automobile revolutionized travel in a positive manner. However, this invention is causing some of the biggest environmental problems as a result of the extensive use of oil extracted from the earth.
• Examine how these three negative impacts changed the environment; list the mechanisms through which this happened. For example, factories caused an increase in pollution through the release of toxic waste, which led to diminished and lost fish populations in rivers.
• Explain the effect of the environmental movement on the process of industrialization in the United States during the 1970s.
• Identify the laws passed to help ameliorate the environmental issues in the U.S. or around the world related to these three impacts. Have any laws been passed since this movement in the 1970s? If there have been laws implemented, summarize the spirit of the law and comment on the effectiveness of the law.
• Based on your research, examine whether the state of the environment has become worse or has improved as a result of these laws. If you think conditions have not improved, suggest solutions or steps that must be done to improve the situation.

Support your statements with appropriate examples and scholarly references. Be sure to include an additional page for references.

Write a 4–5-page paper in Word format. Apply APA standards to citation of sources. Use the following file naming convention: LastnameFirstInitial_M1_A3.doc. For example, if your name is John Smith, your document will be named SmithJ_M1_A3.doc.