THE UNIVERSITY OF TOLEDO
COLLEGE OF ENGINEERING
ENGINEERING TECHNOLOGY DEPARTMENT

FUNDAMENTALS OF ELECTRICITY 
ENGT 3050 
LABORATORY MANUAL	

Prepared by: Frederick J. Nelson
January, 2005

FUNDAMENTALS OF ELECTRICITY 
ENGT 3050 
LABORATORY MANUAL
TABLE OF CONTENTS
•	SAFETY REGULATIONS
•	LABORATORY GRADING POLICIES
•	LAB REPORT GUIDELINES
•	EXERCISES
1.	Resistor Color Code
2.	Ohm's Law
3.	Power in DC Circuits
4.	Resistors in Series
5.	Resistors in Parallel
6.	Mesh Analysis and Thevenin's Theorem
7.	The Oscilloscope and the Function Generator
8.	RL Circuits and Time Constants
9.	RL Circuits with AC Sources
10.	RC Circuits and Time Constants
11.	Frequency Effects in Series RLC Circuits
12.	The Silicon Diode and the Diode Curve

SAFETY REGULATIONS

•	No smoking, no chewing tobacco, no eating, no drinking.
•	Unauthorized experiments are not permitted. Scheduled experiments must be completed during regularly scheduled lab periods or during open lab periods when a lab instructor or assistant is present.
•	All injuries must be reported to the lab instructor immediately.
•	You work area must be clean when you leave.
•	All lab equipment must be turned off when you leave.
•	If you are under a doctor's care or are taking any medications that might interfere 
with your ability to perform the lab activities, please inform the lab instructor.
•	Shoes and shirts must be worn in the lab at all times.
•	Radios or other audio devices, including those with headphones, are not permitted in the lab.
•	All lab equipment must be treated with proper care and respect. Abuse of the equipment will not be tolerated.
•	Additional safety information may be communicated by your lab instructor during regularly scheduled lab periods.

LABORATORY GRADING POLICIES
•	Laboratory exercises will start in the second week of the term.
Your lab grade will be based on the average of the lab report grades for these exercises, plus a component for attendance and participation.
•	In general, the lab reports are due one week after the lab is performed. A penalty of twenty percent per school day will be assessed for reports that are submitted late.
•	Lab reports must be typed and printed using word processing equipment.
•	If calculations are performed using software such as Minitab® or Excel®, then the outputs from these programs can be used as report appendices, but it is your responsibility to extract the appropriate values from these computer outputs and use them to address the issues raised in this manual.
•	It is expected that lab reports will be complete and will contain all of the elements listed under the instructions for each laboratory exercise.
•	There will be grade penalties for work that is clearly inaccurate or sloppy.
•	There will be grade penalties for lack of proper units associated with numerical data.
•	Each student is responsible for writing his / her own lab report, even though data is frequently shared. Duplicate lab reports will be given a single score that will be shared equally among the participants.
•	In general there are no make-up labs. If you are physically unable to attend your scheduled lab session, you may be able to attend another lab section. Otherwise, obtain the data from your lab partners and prepare your lab report on the basis of that data.
•	It is acceptable to seek advice from other persons concerning laboratory data analyses, but each student is ultimately responsible for the content of his / her own lab report.

LAB REPORT GUIDELINES
•	All reports must be written in the English language.
•	All statements must be written using proper sentence structures with subjects and verbs.
•	All words must be spelled correctly.
•	All sentences must utilize proper punctuation.
•	Always refer to what was done using the past tense.
•	Do not use pronouns or the names of persons.
•	Do not use "run-on sentences". Minimize the use of words such as "and then".
•	When appropriate, all numerical information must be accompanied by proper units.
•	All tables must be numbered and labeled, e.g., Table 1, Resistance Data.
•	All graphs must be numbered and labeled, e.g., Figure 2, Voltage versus Current. 
•	All tables and graphs must include proper labeling to identify the meaning of numerical information and associated units.
•	In general, tables and graphs should be discussed in the body of your report. Don't flop a page full of numbers before the reader and then say nothing about what the numbers represent or where they came from.
•	Reports must be written and assembled in a concise and logical manner. A stranger with minimal understanding of the subject matter should be able to read your reports and deduce the essence, and perhaps even some of the details, of what you did and what happened.
•	Imagine that your reports are for the benefit of your employer, who signs your paychecks, but may know little or nothing about the details of your work. If you were the employer you would want reports to be accurate, complete, neat and understandable. You have to assume that others expect no less.

EXERCISE NO. 1 
RESISTOR COLOR CODE

Objectives: The objectives of this laboratory exercise are to become familiar with the resistor color code and to use a digital multimeter (DMM) to measure resistance.

Procedure:

1.	Determine the color codes of the resistors listed below. Locate one resistor in your parts kit for each value.

RESISTANCE (OHMS)

10  Ω
100  Ω
220 Ω
330 Ω
1 kΩ
5.1 kΩ
10 k Ω
100 k Ω
 1 MΩ

2.	Based on the tolerance, create a table with the nominal resistance value in the first column, the color code in the second column (if the colors are readable), the minimum resistance in the third column and the maximum resistance in the fourth column. Reserve a fifth column for the measured resistance values.  The resistors from the ELENCO kit are 1%.

3.	Use the DMM to measure the resistance of each of the resistors located in step 1, according to the lab instructor's directions. Remember not to hold the resistor leads with your fingers when taking measurements, since this may affect the measured values. Use the most sensitive resistance scale possible in each case to obtain the most accurate measured values.

4.	Record the measured resistance values in column five of your table, and check to make sure that the measured values lie within the expected tolerance ranges. If a measured resistance lies outside of the expected range, check the color code of the resistor and check to make sure that the DMM procedure has been followed properly. It is very rare that a commercial resistor has a resistance value outside of the specified tolerance range.

5.	Data Analysis: None

The connection diagram for this lab is very simple.  Use this setup for all resistor values:

EXERCISE NO. 2 
OHM'S LAW

Objective: The objective of this exercise is to show that the current and the voltage are linearly proportional in a resistive DC circuit and that the constant of proportionality is the resistance of the circuit.

Procedure:

1.	Connect the circuit shown in Figure 1 using a 1 kΩ resistor for the resistance. The portable multimeter can be used for the voltmeter. The DMM, used as an ammeter, must be connected in series between the power supply and the resistor.

Figure 1

2.	Beginning at 0.0 volts, increase the voltage across the resistor in 1.0 volt steps to a maximum of 12.0 volts. Record the voltage and current in a table in your lab notebook for each step.

3.	Replace the 1 kΩ ohm resistor with an 5.1 kΩ resistor and repeat the voltage and current measurements from zero to twelve volts. Record this data in a table in your lab notebook.

4.	Turn off all power to the circuit and remove the resistors from the circuit board. Using the DMM as an ohmmeter, measure and record the actual resistance of each of the two resistors.

Data Analysis:

1.	Use your data to create graphs of current versus voltage for the two resistors. Note that voltage is the independent variable and it must be plotted on the horizontal axis. Use linear scales and label them properly.

2.	Draw the single "best" straight line through the data points for each resistor. DO NOT "CONNECT THE DOTS!" Your straight lines may not necessarily touch all, or even any, of the plotted data points. Make sure that all scales are properly labeled and that each line is labeled according to the nominal resistor value that was used for that data set.

3.	Choose two convenient points on each of your straight lines and use them to calculate the slopes of your lines. It is better if you do not choose two points that are very close together. These slopes represent the reciprocal resistance, or conductance, values for each of your two circuits.

4.	Calculate the reciprocals of each of the slopes determined in step 3, above. Create a table that compares these resistance values with the nominal and measured resistance values.

Report:
Write a tech brief that summarizes this experiment. Your tech brief must include:

•	The objectives of the exercise.
•	A brief summary of the procedures.
•	A circuit schematic.
•	A table for voltage and current values.
•	Graphs of current versus voltage.
•	A table for resistance values.
•	A brief discussion of your conclusions, including how this experiment verifies (NOT PROVES) Ohm's Law.

EXERCISE NO. 3
POWER IN DC CIRCUITS

Objectives: The objectives of this exercise are to show how resistor power dissipation is related to voltage, current and resistance in a DC circuit.

Procedure:

1.	Connect the circuit shown in Figure 1 using two 1 kΩ resistors in series. The portable multimeter can be used for the voltmeter. The DMM, used as an ammeter, must be connected in series between the power supply and the resistors.

Fig. 1	
		
Beginning at 0.0 volts, increase the voltage across the resistors in 1.0 volt steps to a maximum of 10.0 volts. Record the voltage and current in a table in your lab notebook for each step.

2.	Replace the 1 kΩ resistors with two 5.1KΩ resistors in parallel as shown and repeat the voltage and current measurements from zero to ten volts. Record this data in a table in your lab notebook.

3.	Turn off all power to the circuit and remove the resistors from the circuit board. Using the DMM as an ohmmeter, measure and record the actual resistance of each of the two connections of resistors (RT).

Data Analysis:

1.	Use your data to calculate the resistor power dissipation (in mW) for each voltage for each RT.
2.	Create a graph of power versus voltage for each of the two RT. Note that voltage is the independent variable and it must be plotted on the horizontal axis. Use linear scales and label them properly.
3.	Create a graph of power versus current for each of the two RT. Note that current is the independent variable and it must be plotted on the horizontal axis. Use linear scales and label them properly.

Report:
Write a tech brief that summarizes this experiment. Your tech brief must include:
•	The objectives of the exercise.
•	A brief summary of the procedures.
•	A circuit schematic.
•	A table for voltage, current and power values.
•	A table for actual resistance values.
•	Graphs of power versus voltage.
•	Graphs of power versus current.
•	A brief discussion of your conclusions, including:

•	Effect of voltage on power for fixed resistance.
•	Effect of current on power for fixed resistance.
•	Effect of resistance on power for fixed voltage.
•	 Effect of resistance on power for fixed current.

EXERCISE NO. 4 
RESISTORS IN SERIES

Objectives: The objectives of this exercise are to examine the behavior of current and voltages for resistors connected in series in a DC circuit.

Procedure:
1.	Construct the circuit shown in Figure 1 on a circuit board.

2.	Use the DMM, connected as an ohmmeter, to measure the resistance of each resistor in the circuit. Note that the power supply must be disconnected when these measurements are made. Record these values.

3.	Use the DMM, connected as an ammeter, to measure the current at points a, b, c, d and e. Record these values.

4.	Use the DMM, connected as a voltmeter, to measure the voltage across each resistor. Record these values.

5.	Use the DMM, connected as a voltmeter, to measure the voltage between points b and e (ground). Record this value.

Data Analysis:

1.	Use your measured resistance values to calculate the current. Create a table of calculated and measured current values for points as b, c, d and e.

2.	Use your measured resistance values to calculate the voltages across each resistor. Create a table of calculated and measured resistor voltages.

3.	Use your measured resistor values to calculate the voltage between point b and ground (e). Create a table comparing this value with your measured value.

4.	Use your calculated resistor voltages to verify (not prove) Kirchhoff's Voltage Law for this circuit.

5.	Use your measured resistor voltages to verify (not prove) Kirchhoff's Voltage Law for this circuit.

Report:
Write a tech brief that summarizes this experiment. Your tech brief must include:
•	The objectives of the exercise.
•	A brief summary of the procedures.
•	A circuit schematic.
•	A table for actual versus nominal resistance values.
•	A table for calculated and measured current values.
•	A table for calculated and measured resistor voltages.
•	A table for the calculated and measured voltage at point B relative to ground.
•	A brief discussion of your conclusions, including:
o	A comparison of current values. Does it matter where the current is measured in a series circuit?
o	A comparison of resistor voltages. Does the voltage divider equation work?
o	A comparison of the voltages at point B relative to ground.
o	Is KVL verified using calculated resistor voltages? Show how.
o	Is KVL verified using measured resistor voltages? Show how.

EXERCISE NO. 5
RESISTORS IN PARALLEL

Objectives: The objectives of this exercise are to examine the behavior of currents and total resistance for resistors connected in parallel (and series) in a DC circuit.

Procedure:

1.	Construct the circuit shown in Figure 1 on a circuit board.

2.	Use the DMM, connected as an ohmmeter, to measure the resistance of each resistor in the circuit. Note that each resistor must be disconnected from the rest of the circuit when this measurement is made. Record these values.

3.	Use the DMM, connected as an ohmmeter, to measure the total resistance of the circuit from the point of view of the power supply. Note that the circuit must be disconnected from the power supply when the resistance measurement is made. Record this value.

4.	Use the DMM, connected as an ammeter, to measure the currents at points A, B, C, D and E. Record these values.

Data Analysis:

1.	Create a table of nominal and measured resistance values.
2.	Calculate the total resistance of this circuit using nominal resistor values. Calculate the total resistance of this circuit using measured resistor values. Create a table comparing the two calculated values and the measured value for the total resistance of this circuit.
3.	Calculate the currents at points A, B, C, D and E using nominal resistor values. Calculate the currents at points A, B, C, D and E using measured resistor values. Create a table comparing the two sets of calculated values and the set of measured values for the currents at points A, B, C, D and E.
4.	Use your calculated currents to verify (not prove) Kirchhoff's Current Law for this circuit.
5.	Use your measured currents to verify (not prove) Kirchhoff's Current Law for this circuit.

Report:

Write a tech brief that summarizes this experiment. Your tech brief must include:
•	The objectives of the exercise.
•	A brief summary of the procedures.
•	A circuit schematic.
•	A table for actual versus nominal resistor values.
•	A table for calculated and measured total resistance values.
•	A table for calculated and measured current values.
•	A brief discussion of your conclusions, including:
o	A comparison of total resistance values.
o	A comparison of current values. Does the current divider equation work?
o	Is KCL verified using calculated currents? Show how.
o	Is KCL verified using measured currents? Show how.
•	An appendix containing total resistance calculations and current calculations.

EXERCISE NO. 6 
MESH ANALYSIS AND THEVENIN'S THEOREM
Objectives: The objectives of this exercise are to compare measured voltage and current values with values obtained from a mesh analysis, to compare measured and calculated values for a Thevenin equivalent resistance and a Thevenin equivalent voltage, and to compare the effects of a Thevenin equivalent circuit on a load resistor with the effects of the original circuit on that same load resistor.
Procedure:
1.	Construct the circuit shown in Figure 1 on a circuit board.

2.	Use the DMM to measure the current through each resistor in the circuit. Record these values.
3.	Use the DMM to measure the voltage across each resistor in the circuit. Record these values.
4.	Remove the 1KΩ  load resistor from the circuit and use the DMM to measure the Thevenin voltage between points "a" and "b". Record this value.
5.	Turn off and disconnect the power supply and replace it with a short. Use the DMM to measure the Thevenin resistance between points "a" and "b". Record this value.
6.	Use your measured values for the Thevenin resistance and the Thevenin voltage to construct the Thevenin equivalent circuit on the breadboard. You may need to obtain some resistors from the instructor to approximate the Thevenin resistance. Replace the 1KΩ  load resistor between points "a" and "b".
7.	Use the DMM to measure the current through and the voltage across the 1KΩ load resistor in the Thevenin equivalent circuit. Record these values.

Data Analysis:

1.	Perform a mesh analysis for the original circuit. Use the calculated mesh currents to determine the currents and voltages for each resistor.
2.	Create a table comparing the calculated and measured currents and voltages for each resistor in the original circuit.
3.	Calculate the Thevenin voltage and the Thevenin resistance from the point of view of terminals "a" and "b".
4.	Create a table comparing calculated and measured values for the Thevenin voltage and resistance.
5.	Use the calculated Thevenin equivalent circuit to determine the current through and the voltage across the 1KΩ load resistor.
6.	Create a table comparing the four different values for the load resistor current and voltage . . . calculated and measured for the original circuit, and calculated and measured for the Thevenin equivalent circuit.

Report:

Write a tech brief that summarizes this experiment. Your tech brief must include:
•	The objectives of the exercise.
•	A brief summary of the procedures.
•	A circuit schematic for the original circuit.
•	A circuit schematic for the Thevenin equivalent circuit.
•	A table for resistor voltages and currents for the original circuit.
•	A table for Thevenin voltage and Thevenin resistance values,
•	A table for load resistor voltages and currents.
•	A brief discussion of your conclusions, including:
•	A comparison of mesh analysis results with measured results.
•	A comparison of calculated and measured Thevenin voltage and resistance values.
•	A comparison of load resistor voltages and currents.
•	An appendix containing the mesh analysis calculations.
•	An appendix containing Thevenin voltage and Thevenin resistance calculations.

EXERCISE NO. 7
THE OSCILLOSCOPE AND THE FUNCTION GENERATOR
Objectives: The objectives of this exercise are to become familiar with the basic operation of the oscilloscope and the function generator and to use the oscilloscope to measure voltage and time.
A good review of the oscilloscope is found on: https://www.youtube.com/watch?v=u4zyptPLlJI
Procedure:
OSCILLOSCOPE DEFAULT SETTINGS 
1. Set the default settings for the oscilloscope according to the instructor's directions. Use these default settings to familiarize yourself with the basic oscilloscope controls.
OSCILLOSCOPE VOLTAGE MEASUREMENTS
1.	Set the TIME/DIV control to 0.1 ms/div and the trigger mode to AUTO. Adjust the focus and intensity controls to achieve a clear display.
2.	Adjust the vertical position control for each channel to center the beam on the screen. The input mode switch should be set on AC.
3.	Connect the input probe for channel I to the PROBE ADJUST terminal on the face of the scope. The ground clip need not be attached. A square wave should appear on the screen. Measure and record the peak to peak voltage, Vp.p, for this square wave using several different vertical sensitivity settings (VOLTS/DIV).
4.	Repeat step 3, above, for channel 2.
5.	Compare the measured values for Vp-p with the calibration value listed on the scope. If there are significant discrepancies, check to see if the RED inner knobs on the VOLTS/DIV controls are in the CAL position. If not, turn them to this position and repeat your measurements.
OSCILLOSCOPE TIME MEASUREMENTS 
1.	Time measurements are best made along the center horizontal graticule line. Using the signal from the PROBE ADJUST terminal, center the square wave vertically on the screen with the VERTICAL POSITION control.
2.	Use the HORIZONTAL POSITION control to line up one rising edge of the square wave with the vertical graticule line that is second from the left side of the screen.

3. Count the number of major and minor divisions across the center horizontal graticule line that span one cycle of the square wave. Multiply the number of major divisions (including the fractional part) by the SEC/DIV setting to determine the time required for one cycle, i.e., the period of the wave.
Calculate the inverse of this value to determine the fundamental repetition frequency for the square wave. Compare this value with the one printed on the scope face near the PROBE ADJUST output pin.
THE FUNCTION GENERATOR
1.	Connect the oscilloscope to the function generator, making sure that the polarity of the connection is correct. Set the function generator for a sine wave output with any amplitude and a frequency of about 1 kHz. Adjust the oscilloscope controls to display several cycles of this waveform on the screen.
2.	Switch the input coupling of the oscilloscope to DC. The sine wave displayed on the screen should not change. Switch the input coupling of the oscilloscope to GND. What happens to the sine wave?
3.	Switch the input coupling of the oscilloscope back to DC. Turn on the DC OFFSET on the generator and watch what happens to the oscilloscope display as the DC OFFSET voltage is varied in the positive direction. Switch the input coupling of the oscilloscope back to AC. What happens to the voltage display?
4.	Turn off the DC OFFSET of the generator and set the input coupling of the oscilloscope to AC. Change the output of the function generator to a triangular waveform and adjust the amplitude to 2 volts peak-to-peak, as measured on the oscilloscope. Set the frequency control on the generator to the maximum possible value with a multiplier of 1kHz.
5.	Determine the period and the fundamental repetition frequency of this triangular waveform as accurately as possible with the oscilloscope.

Report: None

Data Analysis: None

EXERCISE NO. 8 
RL CIRCUITS AND TIME CONSTANTS

Objectives: The objectives of this exercise are to determine the time constant of an RL circuit and use it to deduce the inductance value.
Procedure:
1.	Measure and record the resistance values of a 10 kΩ and a 5.1 kΩ resistor.
2.	Obtain an inductor from the instructor and use the DMM to measure its resistance value, R.
3.	Measure and record the inductance of the coil according to the instructor's directions.
4.	Construct the circuit shown in Figure 1 on a circuit board. Set the function generator to create a square wave with a fundamental frequency of six or 500 Hz and a peak to peak voltage of 10V. The exact frequency does not matter as long as the coil can be fully fluxed during one half of the square wave cycle. Use channel one of the oscilloscope to display the voltage at point "a". Confirm the frequency and amplitude of the square wave.
 
Figure 1
5.	Connect channel one of the oscilloscope to point "b" such that the voltage across the 10 kΩ resistor is displayed on the screen. Adjust the time scale to 10μs per division. Adjust the oscilloscope controls such that one charging cycle is displayed, using as much of the vertical height of the screen as is practical. Align the leading edge of the charging cycle with the intersection of a vertical and a horizontal line on the screen such that screen divisions can be conveniently counted.
6.	Take a picture of the waveform for analysis later.

Data Analysis:

1.	Your picture should look like the picture above with a rise time to a final value.  By observation, find the 63% point which is e-1 or the point at which t = L/R (tau or the time constant).
2.	Use your time constant, together with the total series resistance, to calculate the inductance of your inductor. Note that the 5.1 kΩ resistor does not contribute toward this calculation in any way. It is merely a shunt across the signal generator.
3.	Create a table that contains the time constant and compares the measured and calculated values for the inductor.
Report:
Write a tech brief that summarizes this experiment. Your tech brief must include:
•	The objectives of the exercise.
•	A brief summary of the procedures.
•	A circuit schematic.
•	A graph of the 10 kΩ voltages versus time.
•	A table containing the time constant and measured and calculated inductance values.
•	A brief discussion of your conclusions.
•	An appendix containing the calculations for the inductor value.

EXERCISE NO. 9 
RL CIRCUITS WITH AC SOURCES

Objectives: The objectives of this exercise are to verify the voltage waveforms for RL circuits with AC sources.
Procedure:
1.	Measure and record the resistance values of a 10 KΩ and a 5.1 KΩ resistor.

2.	Obtain an inductor from the instructor.

3.	Measure and record the inductance of the coil according to the instructor's directions.

4.	Construct the circuit shown in Figure 1 on a circuit board. Set the function generator to create a sinusoidal wave with a frequency of 500 Hz and a peak-to-peak value of 10 volts. Verify the frequency with the frequency counter and verify the amplitude by connecting channel one of the oscilloscope to point "a". Use the AC setting for the oscilloscope and make sure that the ground position is centered vertically on the screen. Adjust the time scale with the scale setting and the "calibrate" knob such that one cycle of the sine wave occupies exactly eight divisions on the screen. Each large division will then correspond to one eighth of a cycle, or 45°, and each small division will correspond to one fortieth of a cycle, or 9°.

Figure 1
5.	Connect channel two of the oscilloscope to point "b", displaying the voltage across the 10 kΩ resistor; along with channel one, which is displaying the source voltage. Trigger the oscilloscope with channel one. Determine the peak-to-peak voltage for the resistor and record this value. Count the number of small divisions between similar points on the two waves and convert this value into the phase angle for the resistor. Record your measured phase angle. Pay attention to the algebraic sign of the angle as well as the magnitude of it, i.e., whether the resistor voltage leading or lagging the source.

6.	Reverse the polarity of the source such that the ground position is at point "a".
7.	Connect channel one of the oscilloscope to point "c", representing the source voltage, and connect channel two of the oscilloscope to point "b", representing the inductor voltage. Make sure that one cycle occupies eight divisions on the screen.
8.	Measure and record the peak-to-peak value and the phase angle for the inductor voltage.
9.	 Repeat steps four through eight at a frequency of 1 kHz, 3 kHz and 5 kHz.
Data Analysis:
1.	Create a table containing the measured resistance values and the measured inductor value.
2.	Using your measured component values, calculate the peak-to-peak voltages and the phase angles for the resistor and the inductor for each of the two frequencies, 5 kHz and 40 kHz.
3.	Create a table comparing measured and calculated values for the peak-to-peak voltages and the phase angles.
4.	Using your measured values, write the sinusoidal equations for the resistor voltage and the inductor voltage at each frequency. Put these equations into a table.
Report:
Write a tech brief that summarizes this experiment. Your tech brief must include:
•	The objectives of the exercise.
•	A brief summary of the procedures.
•	A circuit schematic for measuring the resistor voltage.
•	A circuit schematic for measuring the inductor voltage.
•	A table for the peak-to-peak voltages and phase angles.
•	A table for the sinusoidal equations.
•	A summary of your conclusions
•	An appendix containing the voltage calculations for a frequency of 500 Hz
•	An appendix containing the voltage calculations for a frequency of 5 kHz.

EXERCISE NO. 10 
RC CIRCUITS AND TIME CONSTANTS
Objectives: The objectives of this exercise are to compare resistor and capacitor voltages during the DC charging cycle of a capacitor and to deduce the time constant of the circuit.
Procedure:
1.	Measure and record the resistance value of a 470 Ω resistor.
2.	Obtain a 10 μF capacitor from the instructor or from your kit.
3.	Measure and record the capacitance of the capacitor according to the instructor's directions.
4.	Construct the circuit shown in Figure 1 on a circuit board. Set the function generator to create a square wave with a fundamental frequency of 100 Hz and a peak to peak voltage of 10V. The exact frequency does not matter as long as the capacitor can be fully charged during one half of the square wave cycle. Use channel one of the oscilloscope to display the voltage at point "a". Confirm the frequency and amplitude of the square wave.

Figure 1
5.	Connect channel one of the oscilloscope to point "b" such that the voltage across the capacitor is displayed on the screen. Adjust the oscilloscope controls such that one charging cycle is displayed, using as much of the vertical height of the screen as is practical. Align the leading edge of the charging cycle with the intersection of a vertical and a horizontal line on the screen such that screen divisions can be conveniently counted.
6.	Reverse the polarity of the source and repeat step 5 for the resistor voltages.

Data Analysis:
1.	Create a table containing the nominal and measured capacitor and resistor values.
2.	Use your measured component values to calculate the circuit time constant.
3.	Obtain the graph of voltage rise and fall across the capacitor with the square wave input. Identify the point on your graph that represents 63% of the maximum capacitor voltage. Identify the time value, as accurately as possible, that corresponds to this voltage. This is an estimate of the time constant, T.
4.	Create a table that contains the calculated time constant and the values obtained from the graph.

Report:

Write a tech brief that summarizes this experiment. Your tech brief must include:

•	The objectives of the exercise.
•	A brief summary of the procedures.
•	A circuit schematic.
•	A table for capacitor and resistor values.
•	A graph of the measured capacitor voltages versus time.
•	A graph of the measured resistor voltages versus time.
•	A table containing the three values for the circuit time constant.
•	A brief discussion of your conclusions, including:
o	A comparison of measured and calculated voltages.
o	A comparison of capacitor and resistor voltages.
o	A comparison of the time constant values.
•	An appendix containing the calculations for the time constant and the voltages.

EXERCISE NO. 11
THE SILICON DIODE AND THE DIODE CURVE

Objective: The objective of this laboratory exercise is to study the electrical properties of the silicon diode and to determine the voltage-current characteristics of a silicon diode.  The devices used in this lab are pictured below and are found in your lab kit:

Procedure:

1.	Use the diode in your kit.  Use 1KΩ for the resistor R1.
2.	Connect the circuit as shown in the figure below (forward bias). Adjust the voltage of the source from 0 to 10 volts in increments of 0.1 volts between 0 and I volt, and in increments of 0.5 volt thereafter. For each voltage setting of the supply, record the diode voltage, the resistor voltage, and the current.

3.	Connect the circuit as shown in the figure below. Note that the direction of the diode has been reversed. Adjust the DC source from zero to 10 volts in increments of one volt. Measure the voltage across the diode, the voltage across the 1 kΩ resistor, and the current for each source voltage setting.

Data Analysis:

1.	Calculate the currents and the resistor voltages under the forward bias condition using the voltage — only diode model. Use the same source voltage values as in procedure step 2.
2.	Calculate the currents and the resistor voltages under the reverse bias condition using the voltage — only diode model. Use the same source voltage values as in procedure step 3.
3.	Create a table of measured and calculated diode voltages, resistor voltages and currents versus source voltage values from minus ten volts to plus ten volts.
4.	Create a scatterplot graph of measured current versus measured diode voltage for your range of values. Use the plotting option that puts the best smooth line through the data points.
5.	Locate the forward voltage, or barrier potential, on this graph and identify the corresponding forward current.
6.	Create a scatterplot graph of calculated current versus calculated (actually, assumed) diode voltage for the same range of source voltage values, based on the voltage — only diode model.

Report:

Write a tech brief that summarizes this experiment. Your tech brief must include:
•	The objectives of the exercise.
•	A brief summary of the procedures.
•	Two circuit schematics.
•	A table for measured and calculated voltages and currents versus the source voltage.
•	A graph of measured diode current versus measured diode voltage.
•	A graph of calculated diode current versus assumed diode voltage.
•	A brief discussion of your conclusions, including your value for the diode current when the diode voltage equals the barrier potential.
•	An appendix containing the calculations for the diode currents.

EXERCISE NO. 12
THE NPN TRANSISTOR

EXERCISE NO. 13
A MEMORY CIRCUIT WITH RELAY

Relay (24 VDC)

The Omron MY2N-D2 is pictured here:

	Omron MY2N-D2 Relay

This relay has a 24 VDC coil.  The coil is labeled (+) on terminal 14 and (-) on terminal 13.  Note the diode which is used as a fly-back diode to minimize current when the coil is being turned off.  Contacts are shown below the coil similar to the contacts of the 12 V relay.  

Terminal Arrangement of Omron MY2N-D2 Relay

The base of the Omron relay is pictured below.  

Screw Terminal Arrangement of Omron MY2N-D2 Relay

Also, the student may use the new pushbutton stations for this lab including the normally closed red buttons and the normally open yellow and green buttons.  Wiring of these buttons is shown in Figure 2-40 below.  Normally open are labelled NO and colored green.  Normally closed are labelled NC and colored red.

Indicator lights are incorporated into the pushbuttons.  Terminals for the lights are labelled X1 and X2.  These lights will illuminate with either the 12 V or 24 V power supplies. They are located on the right side of the figure below and labelled X1-X2.  

Above – Front side – Below – Back Side of New Pushbutton Stations

EXERCISE NO. 14
A Robot Assembly

Create a lab group of three and get a robot car kit from the instructor.
Assemble the robot car using the attached video instructions. 

Please insure:
1) You are very careful and take your time.  There are no spares so dropped parts could be a major problem.
2) Each person takes a turn working on the assembly.  Everyone should be paying attention and triple checking that the instructions are followed correctly.
3) You are using the correct sized screws.  Each screw has a diameter and length.
4) The parts are mounted on the correct side and correct holes.
5) When complete, go back and retighten all the screws.
At the end of the lab submit a selfie with you, your lab partners, and your robot car.  Everyone must submit for credit.
Note that it may take more than one lab to complete the assembly.

EXERCISE NO. 15
A Trial with Robot
Verify
1) Label your robor with it's name and exchange robot cars with another group
2) Check and tighten any loose screws
3) Carefully trace and check the connections to insure they are plugged into the correct location on the board.
4) Carefully check the connections to insure Vcc goes to Vcc
5) Insure the Blutooth module is aligned correctly.
6) Insure the controller module is plugged in in the correct location.
7) Document all found issues
8) Exchange with a different group and repeat 1-7
9) Get approval from instructor
9) Plug into with computer with provided cable and and check if lights appear on arduino, controller, Blutooth, amd both collision modules.  Batteries are not need.

Arduinio
1) Install Arduino software using the robot car info instructions
2) Connect cable to your computer
3) Configure the Arduino software
4) Run the Blink example software and insure it runs correctly

Mixly
1) Install Mixly software
2) Write a program to move the servo and run on the robot car
3) Make a short video of the servo moving

Upload video and issue notes in Word format to Blackboard.