EE101: Introduction to Electrical Fundamentals Lab

EE101 Final Exam
The final exam will be given during normal class time.  The exam will consist of a multiple-choice section and a practical section.  The multiple choice problems (about 20) will cover material from the 11 lab exercises, the reading assignments, and topics discussed during the lab sessions.  The practical problems will require observing a circuit and test equipment set up at a lab station, then answering questions such as waveform period, frequency, and peak-to-peak voltage displayed on the oscilloscope, the current in a circuit branch based on the measured voltage and the known resistance, and so forth.

The exam is closed book (no books or notes).  Calculators are allowed for numerical computation only (no stored formulas, text, or other material).  Students will work individually, not as teams.

The course evaluation survey will also be available this day.  Please give your honest and detailed assessment of the course, the instructor, and areas that should be addressed in the future.  Thank you!

I truly enjoyed the opportunity to work with you this semester.  Have a great summer!

NOTE:  Instructions on viewing the list of final exam scores and course grades will be emailed to the address of each student.  To verify your official email address, go to MSU My Info.

Lab #11:  Digital Logic Gates
This is the last lab of the semester!  In this exercise you will use some simple digital logic gates to make a combinational logic network.  NOTE that you need to look up a datasheet and prepare some information PRIOR to coming to the lab.

Reminder:  we will have the EE101 FINAL EXAM during the normal class time next week (April 29-30).

I will hand out a review sheet for the final exam this week.

To help with the practical part of the exam, here is an oscilloscope worksheet for you to practice on.  I won't be collecting nor grading the worksheet:  it is just for your own practice.  Here are the worksheet solutions .

Another Reminder:  there are three audio-related events on the MSU campus 4/28-4/30.  These are free and open to the public, so you are invited to attend if you are interested.

Lab #10:  Voice-activated switch kit: completion and testing
Nice work on the soldering so far:  you are all doing a great job with the circuit assembly!

The entire assembly of the kit (except for C3 and mic) needs to be done BEFORE you arrive at class this week.  See me or ask the department secretary if you would like to get into the lab to finish up your soldering.

If you have not done so already, you should perform the op amp measurements from Lab #9, and then proceed with the final assembly and testing of the entire circuit.  Plan to turn in the completed Lab #10 write-up (and Lab #9 if you did that separately) before you leave.

Reminder:  we will work on Lab #11 (digital logic) on April 22-23, then have the course final exam in class on April 29-30.  You're almost done with EE101!

Lab #9:  Voice-activated switch kit: assembly
This week and next week are devoted to constructing the voice activated switch (VOX) kit.  Note that you should NOT install capacitor C3 nor the microphone onto the board until you do the required tests on the op amp stages.

I recommend that you solder some spare wires onto the PC board connections (A-F) so that it will be easier to hook up the input and output circuits from your breadboard to your PC board.  You can attach the studs in the kit later if you want.

The physical assembly of the kit (except for C3 and mic) needs to be done BEFORE you arrive at class April 15-16.  If you do not finish the assembly during the lab period this week on April 8-9, be sure to come back sometime before the following week and get the soldering done.

Refer to a Soldering Tips document if you haven't done much soldering before.

REMINDER:  The homework paper for the Roger Boisjoly lecture is due at the start of class on April 8-9.

Lectures by Roger Boisjoly

HOMEWORK ASSIGNMENTfor EE 101:

• Attend either (or both) of the lecture presentation by Mr. Roger Boisjoly
  on Wednesday, April 2, 2003.
• Write a one page (minimum) summary of your reaction to what Mr. Boisjoly has to say.
• Your paper should be written carefully using a word processor, spell checked, and reviewed for proper grammar and punctuation.
• The papers are due at the start of lab next week (April 8 for Section 1 and April 9 for Section 2).

Lab #8:  2-stage Amplifier

This experiment is a continuation of Lab #7, but this time with a two op amp circuit.  The circuit is similar to what will be used in the voice activated switch project (Labs 9 and 10).

NOTE that you will begin assembling your voice activated switch (VOX) kit next week.  Each student needs a kit.

You will be soldering components to a printed circuit board.  If you haven't ever done this sort of thing, refer to a Soldering Tips document.

Lab #7:  Op Amps

NOTE:  You will need to do P1-P4 of Lab #7 BEFORE you come to class!  It requires looking up some information on the web (an LM358 datasheet).

HOMEWORK:  Please read the textbook pp. 238-242 before coming to lab this week.

IMPORTANT:  You need to buy the sound activated switch project kit (~$10) from the EE Storeroom (6th floor Cobleigh) BEFORE coming to the lab.  We will be using the operational amplifier chip from the kit.

Topics:  Reading a datasheet for an integrated circuit, understanding basic op amp features, and assembling simple op amp circuits on the breadboard.

Lab #6:  Introduction to Matlab

REMINDER:  We will meet in the ECE Computer Lab (Room 625 Cobleigh) this week.  You need to have an MSU computer account AND an ECE printing account BEFORE you arrive at the lab!

Topics:  Using MATLAB for simple calculations, plotting, and signal generation.

MID-TERM EXAM results (out of 39 points total):

max:  37
min:  14
average: 26

Students scoring 30 or better did well (A and B range).
Scores between 20 and 30 are in the C or D range.
Scores below 20 indicate that some additional work is needed. I want ALL of you to succeed in this course:  please do not be shy about asking for extra help or advice!!!

Spring Break (no lab this week)

MID-TERM EXAM

The exam will be held during the normal lab time.  The exam will consist of a multiple-choice section and a practical section.  The multiple choice problems (about 20) will cover material from Lab #1 - #5, the reading assignments, and topics discussed during the lab sessions.  The practical problems will require observing a circuit and test equipment set up at a lab station, then answering questions such as the frequency and peak-to-peak voltage displayed on the oscilloscope, the current in a circuit branch based on the measured voltage and the known resistance, and so forth.

The exam is closed book (no books or notes).  Calculators are allowed for numerical computation only (no stored formulas, text, or other material).  Students will work individually, not as teams.

Key areas to review are:

• Basic lab procedures (using the oscilloscope and understanding scope measurements; using the multimeter for current, voltage, and resistance; breadboard connections, etc.)

• Ohm's Law, Kirchhoff's Laws and HOW TO APPLY THEM!

• Electrical measurement units, unit prefixes, and conversions

• Resistor and capacitor schematic symbols and device labels (codes)

• Diodes

• Series and parallel resistor combinations AND formulas

• Component tolerance (nominal vs. actual)

• Graph and report preparation

REMINDER:  Next week is Spring Break.  Enjoy your time off!!  The following week (3/18 and 3/19) we will meet to do Lab #6 in the ECE Computer Lab (Room 625 Cobleigh).

If you have not already done so, you MUST sign up for a free MSU computer account, then talk to Sharon on the ECE office (610 Cobleigh) to arrange for printing privileges in the ECE Lab.  This must be done BEFORE you arrive for Lab #6.

Lab #5:  Electric shock, and a simple diode circuit.

Topics:  Resistance of the human body to electrical current; diode half-wave rectifier circuit.

REMINDER:  The next lab session (3/4 and 3/5) will be the midterm exam.

Lab #4:  Frequency, Period, and Phase.

Here is an oscilloscope worksheet, and here is the worksheet solution.

Topics:  Frequency, phase, and voltage/current relationships.

• Frequency of a periodic waveform is measured in hertz [Hz], meaning cycles per second.  The period of a periodic waveform is the reciprocal of the frequency, with the unit of seconds.  The period of a waveform can be determined directly from the oscilloscope screen by counting the number of divisions between waveform repetitions, then multiplying by the time scale:  Y divisions times X seconds/division = period.  The frequency can then be determined as the reciprocal of the period.

• Measuring time differences on the oscilloscope is often more accurate if "steep" waveform segments are compared (like zero-crossings of a sine wave) rather than "shallow" features (like the rounded peaks of a sine wave):  it is easier to locate the steep feature at a specific time.  If zero-crossings are used, be sure the waveform is centered properly so that the centerline is actually at zero.

• Two signals with the same frequency may have a relative time delay between them.  This is called a phase shift.  If the two waveforms are displayed simultaneously on the two separate channels of the oscilloscope, the delayed waveform will appear shifted to the right relative to the undelayed waveform.  The 'scope can be used to measure the relative time delay, and the phase shift can be calculated by determining the fraction of the waveform period that is represented by the delay:  phase shift = (delay/period)*360 degrees, for example.

• When two signals with a phase shift are added together, the amplitude of the sum will not in general be equal to the sum of the individual amplitudes, since the peaks of the waveforms do not occur at the same time.  The MATH function on the 'scope allows the sum (or difference) of the two input channels to be displayed on the 'scope screen.

Lab #3:  Capacitors and Frequency Response.

Assignment:  are you starting to wonder why clearly specifying measurement units is so important, and why the instructor is so picky about it?  Read the article from the December 1999 issue of IEEE Spectrum magazine on why the Mars Climate Observer crashed into Mars rather than going into the intended orbit:  Why the Mars Probe Went Off Course.  One short excerpt:

"NASA assigned three separate teams to investigate the embarrassing, US $125 million debacle and determine its cause. Preliminary public statements faulted a slip-up between the probe's builders and its operators, a failure to convert the English units of measurement used in construction into the metric units used for operation."

Topics:  RC circuits, frequency response measurement, semi-log graphs.  Here is the theoretical frequency response plot for the RC and RR circuits in Lab #3.

• Capacitors are circuit elements that temporarily store electrical charge.  If a circuit causes a current to flow through a capacitor, a voltage develops across the capacitor that is proportional to the amount of electrical charge delivered by the current.  The unit of capacitance is the farad, abbreviated "F".

• Physical capacitors come in a variety of shapes and sizes.  Plastic and metal film capacitors look a little bit like tan, brown, blue, or red Chiclet-brand gum with two parallel wires coming out.  Aluminum electrolytic capacitors look like metal cans about the diameter of a pen cap.  Some capacitors require a specific polarity (positive/negative) in the circuit.  Typical capacitors used in ordinary circuits range from hundreds of picofarads (pF, pico = 10^-12) to thousands of microfarads (mF, micro=10^-6).  For some reason, capacitors are almost never referred to in nanofarads:  it is traditional to say 0.001mF or 1000pF instead of 1 nF.

• Capacitors are often labeled with a 3 digit code followed by a letter, like "103K".  Referring to the three digits as ABD, the capacitor value in picofarads is ABx10^D pF.  For example, "103" would mean 10 x 10³ pF, or 0.01mF (microfarads).  The letter indicates the tolerance:  M=20%, K=10%, J=5%, G=2%, F=1%, and E=0.5%.

• Simple circuits involving resistors and capacitors are called "RC circuits".  RC circuits often allow the capacitor to charge or discharge through a resistor, and the larger the resistance the longer it takes for the capacitor to charge or discharge.  The product of R and C is known as the RC time constant for the circuit, and the units of R (ohms) times C (farads) is seconds.  The reciprocal of the time constant is 1/RC, and has the units of radian frequency (radians per second).  Radian frequency can be converted to hertz (cycles per second) by dividing rad/sec by 2p.  This frequency roughly corresponds to the separation between the low frequency behavior of the circuit and the high frequency behavior of the circuit.

• For this experiment you will be producing a graph of the frequency response of a simple RC circuit.  The graph will be on semi-log graph paper.  This type of graph paper has one axis scale that is linear (normal) and the other axis scale is logarithmic in powers of 10.  This type of graph is useful when there is a known exponential relationship for the data, or if there is a large range of values (small to large) to be plotted.

Lab #2:  Voltage and Current in simple circuits.
 

Here is the cumulative histogram (both lab sections) for the 4.7kW resistors tested in Lab #1.

Assignment:  before next week (Lab #3), read chapter 20 up through page 154.  Also read chapter 31, pp. 279-287.

Topics:  Kirchhoff's Laws, voltage and current measurement.

• A circuit node is a point where two or more elements (circuit branches) are connected together.  A circuit loop is a closed path from one node through a sequence of circuit branches and back to the starting node without the path crossing itself.

• Kirchhoff's Current Law (KCL) states that the sum of all currents entering a node must be zero.  In other words, the total current entering a node must equal the total current leaving the node.

• Kirchhoff's Voltage Law (KVL) states that the sum of voltages around a circuit loop must be zero.

• The convention for voltage and current in a resistor is

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Carefully follow Multimeter procedures in order to keep track of signal polarity.

• For current (ammeter mode), connect the red lead to the meter's current input and the black lead to the common input.  The meter must be inserted into the circuit branch where the current is to be measured:  current must flow through the meter.  If the current reads positive, this means the current is entering the red lead, passing through the meter and exiting the black lead.  If the current reads negative, the flow enters the black lead and exits the red lead.  The ammeter acts like a short circuit (no voltage across the meter).

• For voltage (voltmeter mode), connect the red lead to the meter's voltage input and the black lead to the common input.  The meter must be used in parallel with the circuit branch between the nodes where the voltage is to be measured.  If the meter indicates positive voltage, the red lead is at a higher potential relative to the black lead, and vice versa.  The voltmeter acts like an open circuit (no current through the meter).

Lab #1:  Series and Parallel resistor combinations, simple circuits, and resistor tolerance specs.
Assignment:  Review handout for Lab #2, and the multimeter notes.

Topics:  Ohm's Law, series and parallel resistor combinations.

• Ohm's Law:  V= I R
  V is voltage with the unit volts, I is current with the unit amperes, or just amps. The unit of resistance is volts/amps, which is called ohms.
  The voltage across a resistor is linearly related to the current through the resistor.  If we make a graph with measured voltage on the vertical axis and measured current on the horizontal axis, the data should produce a line with slope equal to R.  You can think of the resistor as taking a current and "making" a voltage equal to I times R.

•  Resistors connected in series are connected end-to-end.  The total equivalent resistance for resistors in series is simply the sum of the individual resistances.

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• Resistors connected in parallel are all connected between the same pair of nodes.  The total equivalent resistance for resistors in parallel is the reciprocal of the sum of the reciprocals of the individual resistances.

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• More complicated networks of resistors can be simplified by applying the parallel and series formulas over and over on each branch of the network.

• Resistors have a nominal value indicated by the colored bands or other labeling.  The actual (measured) resistance will vary from the nominal value due to subtle mechanical and chemical differences that occur during manufacturing.  The manufacturer specifies the maximum deviation from the nominal value as a percentage.  This range of deviation is called the tolerance of the resistor family.  Typical tolerance values are 1%, 5%, or 10%.

First class meeting
Assignment: 

1. Go to the ECE Shop (622 Cobleigh) and buy the EE101 lab kit ($2.80 for parts, $24 for prototype board).  There will be a separate project kit (~$10) to buy later in the semester.

2. Read chapters 1, 5, and 19 in the textbook.  NOTE in particular the details of series and parallel resistor combinations (pp. 123-125).

3. Prepare a table showing the standard SI unit prefixes for the range from 10^-12 to 10¹².  Hand in at the start of class next week (January 28-29).  Your table should look like:

Multiplier        Unit Name       Abbreviation
  10^-12              pico                     p
  10^-9                nano                    n
...etc...

Topics:  Basics of oscilloscope and function generator.

• In ECE we use lots of range units:  pico (10^-12), nano (10^-9), micro (10^-6), milli (10^-3), kilo (10³), etc.

•  Oscilloscope shows voltage (vertical scale) vs. time (horizontal scale).  The scope display shows the time resolution and amplitude resolution in units per division, where a "division" refers to the approximately 1cm square grid lines on the screen.

• We generally will set the scopes for 20MHz bandwidth:  go to the vertical display menu (button below vertical controls) and select 20MHz.

• If the waveform "rolls" horizontally instead of sitting still, make sure the trigger level and channel is selected properly.

• Adjusting the vertical and horizontal controls acts sort of like a microscope for electrical signals:  we can see details on very short time intervals. 

• Relationship between frequency (Hertz, cycles per second) and period (seconds per cycle) is a reciprocal:  period = 1/frequency.