May 10, 2020
Scores for Exam 3 have been posted to Canvas. Links to the solutions are on the quiz page. The average score was 32.9 out of 40.
May 5, 2020
Solutions to many of the diode, BJT, and MOS quizzes given since spring break (and relevant to Exam 3) have been posted.
Here is the solution to exam 3 from last year. Also, the solutions to HW 10 have bee posed — see the links in MOSFET section at the bottom of the homepage.
May 3, 2020
Solutions to HW problems D2 and D3, and B1 - B5 have been posted. Solutions to HW problems M1 - M5 will be posted Tuesday morning.
May 2, 2020
Reminder: The third exam for EE 230 is scheduled for Wednesday, May 6, starting at 7:30 a.m. (Bleh.) This is the time set by the Registrar. Of course, finals are normally for two hours, but we will extend the time to four hours, given the strange days that we are living through. I will email the exam to everyone at 7:30 a.m. You can start whenever you want. You will need to return the exam by uploading to Canvas or emailing the pdf to me before 11:30 a.m.
If you have any issues that will affect your ability to take the exam at that time — far-away time zones, technology limitations, clashing exam schedules, or anything else outside of your control — please let me know right away so that we can make adjustments for you. (Unfortunately, "Not being prepared." is not a mitigating factor.)
Here is Exam 3 from last year. You can use this in your preparations. I will post solutions to this old exam in a couple of days.
On a related note, I posted the solutions to Exam 2 a while back — perhaps you have already stumbled across them. The links are on the quiz page of the web site. I have asked the Lab TAs to help in grading some of those. So your Exam 2 score should show up on Canvas sometime "soon", depending on when your TA has time available to get through them.
As always, if you have questions, be sure to ask.
Apr 29, 2020
The MOS SpiceLab is available, if you are interested in doing it. To re-iterate, the three SpiceLabs now form a smorgasbord — do two out of three. If you have already done both the diode and BJTs labs, then you are finished. If you have finished the only diode lab, then you can choose either the BJT or MOS lab — I think they involve a similar amount of work, so it is really a matter of which you prefer. If you haven't done any labs yet — well, you should probably get started. Finally, if you have the time and inclination to do all three labs, then the third lab will be treated as extra credit to boost your total lab score.
The last part of HW M5 is unreasonably difficult to do in an exact form. So I have offered up three alternative methods for solving it. If you have been struggling with that one, take a look at the commentary that I've added to do that problem, and try one of my proposed approaches, any one of which should be simpler than trying to do it exactly.
Since I'm in a good mood, I'll extend an extra HW freebie to everyone. If you would like a bit more time to finish the HW, or would like more time to finish your 400 other projects, you can extend the HW submission time through the weekend.
Apr 27, 2020
SpiceLab news: I realize that SpiceLabs are challenging. They are certainly challenging for me to create. And, while running the simulations should be pretty "straight-forward", the quirkiness of the SPICE programs and everyone's general unfamiliarity with them make the work challenging for you, too. On top of that, we are running out of time. I've been pondering how create enough material for people to learn about electronics while still being reasonable under the unusual circumstances. In light of my own concerns, here are a couple of changes regarding the SpiceLab work:
- I will still assign SpiceLab 9. It will probably ready tomorrow. That will make a total of 3 SpiceLabs.
- We will change the requirements to: Do two SpiceLabs out of the three available. You pick the two you want to do. (Since most people have finished or are well on the way to finishing the diode exercises, the choice effectively boils to doing either the BJT lab or the MOS lab.)
- Then the "lab" grade will be based on 9 pieces of work: 6 cookbook labs done prior to spring break, 1 lab project done prior to spring break, and 2 SpiceLabs. That works out to 500 lab points.
- You can still choose do all three SpiceLabs. They aren't intended to be "busy work" to keep people occupied — I'm trying to come up exercises that demonstrate basic principles or show some examples of real, practical circuits. (Which is part of the reason that they take so long to generate.) For those genuinely interested in electronics (approx. 4.2% of the class), doing all three labs is probably a good idea — at least at some point, if not by the end of the semester. For anyone choosing to do a third lab and submit it, the extra work will treated as extra credit that can be used to bolster the lab score. In principle, your lab total could then be as high as 550 out of 500 (assuming that you never missed a single point). The extra lab points might come in handy to offset exam or quiz scores.
- It is still permissable to do the SPICE work with your lab partner. Of course, the expectation is that you are actually collaborating, and it's not just a case of one person getting a free ride. Make sure that when you submit the report, it clearly states that the report is intended for two people.
Hopefully, that makes things a bit easier for everyone to plan their last two weeks.
A new versions of quiz 28 and a first version of quiz 29 ready to go. Quiz 29 (The last one!) will have both NMOS and PMOS transistors, either in two separate circuits, or possible a single circuit with both types of transistors together.
Apr 26, 2020
The dreaded SpiceLab 8 has landed. See the schedule page — hover the cursor trepidatiously over link before clicking.
Apr 25, 2020
New versions of quizzes 27 and 28 are loaded and ready to go. Reminder: Today is the last day for quiz 27.
Apr 24, 2020
The final homework set has been posted. It is due on May 1.
Apr 22, 2020
Quizzes 26 (round 3) and 27 (round 1) are available to take today at 4:00.
Quiz commentary: Quiz 26 is (meant to be) quite easy. Quiz 27 is harder. Note that you should be able to handle an NMOS circuit that requires solving a quadratic equation — either the NMOS is in ohmic mode, there is a resistor voltage included in vGS, or some other weirdness. Get your calculator set up to do the work of solving quadratics for you. Although all the examples show the tedious math to solve the quadratic equations by hand, it is not necessary to do that for quizzes, etc. Set up the relevant KVL or KCL equation from the circuit, and let the calculator do the work. As always, you should check your answers — plug them back into the circuit to confirm that everything checks. Of course, if you really like doing quadratic algebra by hand, that's fine — solve away!
Reminder: HW set 9 is due today. Upload on Canvas before midnight. If you are using a freebie, you will need to send your pdf to me by email.
Apr 21, 2020
The missing homework B3 has been found. You can check it out via the schedule or homework pages.
Apr 20, 2020
Reminder: Today is the last day to take quiz 25.
Now we move from the BJT era to the MOSFET era. Of course, that means that we are getting close to the end of EE 230 WooHoo! For the adventurous, the first NMOS quiz can be taken today.
- Starting with the NMOS quizzes, there will be a slight format change — you will not be able to see the quiz unless you are taking the quiz. So don't click on anything until you are ready to do actually do the quiz and submit it.
- From this point on, I will not give full credit for quiz submissions that are answers only. You must show your work. In other words, we are going back to the original (pre-virus) policies regarding quiz work. If you provide only answers, without any supporting work, you will get 3 points if the answers happen to be correct and no points if they are not. By now, there are only a tiny handful of people submitting "answers only" quizzes.
- I will still accept solutions by email, but make sure that they arrive before 5:00 p.m. on the day you are taking a quiz. And although I still prefer that you use the quiz sheets to write the answers and submit a pdf of that, I will still accept solutions written on a separate sheet of paper. However, if using a separate sheet, do me a favor and add some sort of identification as to which particular version of the quiz you are doing (add the date, add the letter to quiz — quiz 24c instead of just quiz 24 — or sketch the circuit onto your sheet). If all I have to look at are a pile of equations, it really slows down the grading. Using Canvas to collect the quizzes has some advantages — flexibility in terms when you can take a quiz and way less paper for everyone — but it takes me about twice as long to grade a quiz set on Canvas versus using paper. And that's when I can find the answers on the sheet easily. Thank you.
Apr 18, 2020
Reminder: Today is the last day to take quiz 24. No quizzes tomorrow. Monday is the last day to take Quiz 25.
Apr 16, 2020
There is a new version of the pnp quiz (Q24) ready to go. Also, as final salute to BJTs, there is Quiz 25, which consists of either two separate (but possibly related) BJT circuits — any combination of npn/pnp and FA/sat — or a single circuit that has 2 or more BJTs in it. When you are feeling good about BJTs (Does that ever happen?), you should try Quiz 25. There will be versions available between today and Monday.
Apr 15, 2020
There are a handful of pnp practice problems available. I realize that it is short notice, but if you wanted to try Quiz 24 today, which will have pnp transistors, you can practice a bit before hand. Of course, there are a few more days to take Quiz 24 after today.
Also, note that today is the last day for quiz 23.
The long anticipated SpiceLab 7 has arrived. Along with (most of ) HW set 9.
Apr 14, 2020
There is a slight change in the schedule today. I'm not quite ready for a pnp BJT quiz, and I assume that most of you are not either. So the start of pnp quizzes is delayed until tomorrow, and the last day for those will be Saturday. I've updated the schedule page to reflect that change.
Apr 13, 2020
New versions of Quizzes 22 & 23 are ready to go. Reminder: Today and tomorrow are your last opportunities to take Quiz 22.
I've re-written the notes for BJT saturation — I think the new version is more readable, particularly in the justification for vCE(sat) = 0.2 V. Be sure to re-read if you are getting ready to take Quiz 23. The notes are a bit short on examples — I will try to add a few more when I get a chance.
Apr 11, 2020
A new version of Quiz 22 is loaded into the quiz cannon and is ready to fire out at 4:00 p.m. The first version of Quiz 23 is also in the breech and ready to launch. Show up at 4:00 if you would like to try to catch either of these.
A note on the differences between 22 and 23: All of the circuits on the two quizzes have the same forms — an npn BJT with some resistors and power supplies attached. In Quiz 22, the BJTs are guaranteed to be operating in forward-active mode. In principle, you don't even need to check, although you end up checking anyway due to the values that I ask you to calculate. In quiz 23, saturation mode is added to the mix — you can be assured that one or both of the circuits has its transistor in saturation. You need to check and confirm your assumed mode of operation. The next round of BJT practice problems that are showing up are the proper place to prepare for Quiz 23. The circuits are the same as in the previous set of BJT practice problems, but now the possibility of saturation is included. Roughly half of the circuits that you ring up will be in saturation. And a small number will be "off", characterized by not having enough base voltage to forward bias the base emitter junction.
You have surely noticed that the practice problems have changed somewhat. Rather that having one giant script that randomly generates different circuits and different values, I have split the scripts so that each one has only one circuit. The scripts are numbered. When you click (or refresh) on a particular number, you will always get the same circuit, but with different component values each time. I've tried to arrange the sequence so that the circuits get harder as the numbers get bigger — for example, circuit 6 should be somewhat trickier than circuit 1. It is not a hard rule, but that is the general trend that I'm trying to achieve. Hopefully this approach will allow you to work a bit more effectively. First, read the notes. Then start on the corresponding set of practice problems, working your way from 1 on up. Do several examples of each circuit to make sure that you have it mastered. Then go to the next. When you are able to work the highest numbered problems, you are probably fairly proficient and ready to take the corresponding quiz. With the new arrangement, if you are stuck on solving any particular circuit, you can focus on that one until you figure it out or can send out a call for assistance. With the old arrangement — one giant script — if you wanted to focus on a particular circuit that was vexing you, it was necessary to madly hit refresh until the probability gods deigned to serve up that particular circuit. And then it would probably have the wrong values. (Also a factor: the new approach makes it easier for me to write and de-bug the scripts.)
Apr 10, 2020
Don't forget that homework 8 is due today. There is an assignment link in Canvas where you can upload your scanned HW solution. That door closes at 11:59 p.m. (I note that about 25 people have already submitted — nice!) If you have late freebies still available, you can use one of those and submit the work on Monday. In that case, you will have to email your pdf to me rather than submit to Canvas. If you don't have any freebies left and you won't be able to finish the homework, then you should contact me. We will see how effective groveling is when done on-line...
- The second offering of Quiz 22 is on Canvas. Take it today, if you are up for it.
- From here on, each quiz will be available for 4 days only. ("Only" Ha!) Make sure that you are aware of the changes in the quiz schedule.
- The beginning and ending dates for the quizzes will be staggered. At most, there will only two quizzes available on any given day.
- The exception to the above two items is Quiz 22, since it is first quiz after the schedule change. (And since only 5 people took Quiz 22 on the first day it was available — the other 150 of you will probably need a bit more time.) Quiz 22 will be available for 5 days, and there will be three different quizzes available on Tue Apr 14.
- Other than that, the procedure for taking quizzes remains unchanged.
- I will point out again that there is a 45-minute limit for taking and submitting a quiz. There is one-hour window in which you can take a quiz — between 4:00 p.m. and 5:00 p.m. — but once you start you have 45 minutes before Canvas will shut you down. We could probably tighten this up even more — most people seem to be finishing quizzes in the usual 10-15 minutes — but given the technological issues that can crop up, it is probably better to leave some cushion.
- You can probably use the timing and spacing of the quizzes to gauge how fast to proceed through the "lecture" material. I've also added a little calendar to the schedule page that might help you plan your time.
Apr 9, 2020
Diode quizzes are done, and we are entering in bipolar junction transistor (BJT) quiz epoch. If you are ready, the first BJT quiz is available today. Of course, there will be several more days to take this initial quiz. I need to adjust the general timing of quizzes so that I'm not making so many different quizzes every day — I'll post a revised quiz schedule later today.
Apr 7, 2020
Reminder: You do not need to send me emails requesting quizzes. I am no longer emailing those out. When you are ready to take a quiz on a particular day, go to Canvas at 4:00 p.m. — a fresh version of each current quiz will be waiting for you there.
More example calculations have been added to the on/off diode example notes. I won't make any further changes to these notes.
Apr 6, 2020
Monday versions of quizzes 19, 20, and now 21 are ready to go. Take one at 4:00 p.m., if you are so inclined.
All of you who have been fretting about homework problems can now rest easy. The problems for HW set 8 are now available. The due date is Friday. Check the schedule or homework pages. (Actually, now is the time to start fretting about homework, because there is now work to be done. All of you who have been concerned about the lack of homeworks should consider the related concepts of "Let sleeping dogs lie." and "Don't poke the monster with a stick." HaHa!)
Apr 4, 2020
"Notes" news – I have added the start of a new set of notes with examples of diodes circuits analyzed using the on/off method. There are only two complementary examples there now, but I will add more over the next couple of days. If you are still a bit puzzled by the whole "on/off approach", take a look at what's there now and check back again later after I've added more examples — I think these might be helpful.
- Saturday versions of quizzes 19 and 20 are ready to go. Take one at 4:00 p.m., if you are so inclined.
- Because the exam gave us a one-day pause in quiz availability, I've adjusted the schedule for diode quizzes slightly. Specifically, there is one extra day to complete the diode quizzes (Wednesday instead of Tuesday). Also, start of the Zener quizzes is delayed until Monday. Check the schedule for details. Make sure that you are aware of the schedule and don't get yourself into the bind of having to do a bunch of quizzes on one day.
Apr 2, 2020
Solutions to homework problems OA7 - OA16 have been posted.
A new version of Quiz 19 and the first offering of Quiz 20 will both be available at 4:00 today. Note that there will be no quizzes tomorrow — presumably most of you will be busy with other matters.
Apr 1, 2020
- Exam 2 will start at 4:00 p.m. on Friday, Apr 3. (I had attempted to change the date in order to free up our Friday afternoon — we all need a little more drinking time — but my suggestion was shot down within five minutes. Actually, I'm surprised it lasted that long. I suppose we could try to find yet another day to move the exam, but it probably best to stick to the original date and get it over with.)
- I plan to conduct the exam just like quizzes 17 and 18. At 4:00 p.m., I will send you an email with the exam attached. You will work the exam, scan your solutions and send it back, either by uploading to Canvas or attaching the pdf to a return email. You will have three hours to work the exam and return it.
- The exam should not take 3 hours — it will be designed for one hour — but I want to give you plenty of time to work it. With some allowance for email or Slack questions, if you are unclear about any of the questions.
- I will not be putting an equation sheet onto the exam. (See similar comments below in regard to quizzes.) If having the equation sheet makes you feel more confident, print out the sheet from the old exam to have by your side.
- If you have vacated the U.S. and are isolating yourself on the other side of the world, such that taking a synchronously-timed exam would cause to have to work very late at night or in extreme early morning, please let me know. If it would help you, we can try to find a more mutually compatible time for you to take the exam. If there any situations like this, we will handle them on a case-by-case basis.
- On Thursday, from 7:00 p.m. to 9:00 p.m., I will make a point of being available on Slack (and email) to answer questions. The idea is to give you chance to ask questions that may also be on the minds of others, and get quick responses. (This is in lieu of our old exam review sessions.) Of course, you can ask questions any time, but I may not answer right away depending on what else I'm doing at that time.
The next version of Quiz 19 is ready, for those of you who are ready to try it. You have a few more days, if you aren't ready yet.
More quiz information
- There is some confusion about obtaining the quizzes through Canvas, so let me try to clarify. My intent is to have the current set of diode quizzes work exactly the same as the two semiconductor quizzes — you will have multiple days in which to do each of the three quizzes. You can choose the day that you want to do each, based on your schedule and your preparation. For instance, the date range for Quiz 19 is Mar 31 (yesterday) to Apr 7 (next Tuesday). It is up to you to make sure that you take quiz 19 on or before Apr 7. Each day, I will load a new version of the quiz onto Canvas. Canvas, being Canvas, will try to tell you that you have a quiz that must be done "today". You can ignore that if you are waiting to take the quiz later. The other time restriction is that a quiz must be done between 4:00 p.m. and 5:00 p.m. Each day, I will "reset the clock" so that quiz is accessible during our class hour on that day. I expect that you will get multiple messages from Canvas telling you that you must complete Quiz 19 on each of the days. At the moment, I don't know any way around that — we will have to treat it as a minor inconvenience in exchange for more schedule flexibility. Be sure to let me know if you still have questions about how this is supposed to work.
- Note that because I am resetting the clock for each quiz, it is possible that Canvas will allow you to take a quiz more than once. (I'm not sure how that will work — we will see what happens after today.) However, I will accept only your first try at each quiz! So don't plan to start until you are certain that you will be able to finish it.
- I will stagger the starts for the quizzes within any group of quizzes. For example, Quiz 19 started yesterday, Quiz 20 will start tomorrow, and Quiz 22 will start on Saturday. This is for my own sanity, so that I'm not creating a bunch of quizzes that will not be used.
- Some of you waited until the very last minute to take both of the previous quizzes. (Some even past the last minute.) This will not be a good idea going forward. For example, if you wait to the last minute for the three diode quizzes, you will be attempting to squeeze three quizzes into one hour. Maybe you can do it, but you will be putting undue pressure on yourself. Obviously, my intent is for you to stagger the quizzes, doing one a day or one every other day.
- I will not be putting equations and other data on the quiz sheets. I assume that you are all doing the quizzes with the class notes open with Professor Google at the ready, so putting extra information on the sheets seems like a waste of space.
Mar 31, 2020
- Today is the last day take quizzes 17 & 18. If you haven't already, send me an email right away in order to take those today.
- As I had said, I'm viewing much of what we do during our new Covid-shaped academic existence as a set of experiments, and I've learned some interesting things with quizzes 17 and 18. If I have time later, I may share some info and observations with you. But now it is time evolve our quiz-taking methods.
- The next few quizzes will be delivered through Canvas. You no longer need to send me emails requesting a quiz and I will not email them to you.
- For now, quizzes must still be done between 4:00 and 5:00 p.m. To a quiz on any day, go to Canvas. The quiz will become available at 4:00 p.m. You will have 45 minutes to work it. Before the 45 minutes is up or 5:00 p.m., whichever comes first, you should upload your solution. In some sense, it is very similar to what we have been doing, except that you obtain the pdf from Canvas, not from me.
- We will continue with the option of sending me your solution by email. That seems to work, and other than keeping track of emails, it is no harder for me to grade than using Canvas. If sending answers by email is easier for you, you can continue to do that.
- In an email submission, you can continue to a) give only the answers in the body of the email (with the attendant grading risk) or b) attach a good scan of your quiz paper with your work. Also, if you don't want to have to print out the original quiz sheet, you can write out your answers on a separate, clean sheet of paper and submit that, as long as you write legibly and clearly indicate your answers.
- A few of you have indicated that you are ready for quiz 19. If so — and assuming that everything goes the way I think it will — it is ready and waiting for you on Canvas. However, before leaping into it, you might want to check the practice problems, which have been updated and linked on our new schedule page. This first quiz will have one simple diode problem AND one problem that requires you to use the exact equation for the diode. Make sure that you are ready.
Mar 26, 2020
I updated the drift/diffusion practice problems. They have been split into two separate scripts — one for drift and one for diffusion. If you are getting ready for Quiz 18, be sure to use the diffusion problems. Also, I added one more type of problem to the drift script — there is now an option that asks for a calculation of current density. This type of question might show up on future versions of quiz 17.
Mar 25, 2020
I sent a long a email explaining how we will do quizzes. Please read it all and make sure that you understand the procedure. If you have questions, be sure to ask before you take the quiz or before the deadline passes for the first quizzes.
The Canvas gizmo for the class is active. Right now, the only thing I intend to use it for is uploading quizzes, homeworks, etc. I don't plan to duplicate anything that is already being done with usual web site to Canvas. As I become more familiar and comfortable Canvas, I may invoke more features. As our fearless leader likes to proclaim, "We will see."
I goofed up with the quiz numbering. Our last in class quiz was #16, so our first "remote" quiz should be #17.
Mar 24, 2020
I’ve fixed up some of the issues with the drift/diffusion practice problem script. Right now it works fine for drift (resistor) problems. I will add the diffusion problems in later.
The revised schedule with the module listing has been posted. Have a look. I'll give more details about how to do the quizzes in a later post. Note that the drift/diffusion practice problems need to be updated — the script is sort-of usable now, but it needs a bit of maintenance work.
Mar 23, 2020
After giving it some thought over the past week, I’ve come to the conclusion that we need to go as asynchronous as possible.
I will also use this time to do some experimentation with online teaching. As I experiment, I will try to keep things as simple as possible for you. But be advised that the methods may change over time.
Here is what I know for sure.
- The schedule will change from a detailed week-by-week thing to a list of “modules” that have material to be learned and exercises with due dates. The modules will include lecture material, practice problems, quizzes, homeworks, and lab work (which will essentially be homework in the form of SPICE exercises). Other that the lack scheduled hands-on labs, it will be pretty the same as what we had been doing, just organized differently.
- As stated before, the “material to be learned” will be essentially the notes that we have been using and that are already on the website. I will be working to enhance those, filling in gaps and tightening up the presentation. I *may* do some recorded lectures, but those would consist of me talking over the notes, and that is likely just as boring and useless as a regular lecture.
- Homework will be essentially the same as before: A set of problems with a due date. You work the problems, scan them into a pdf, and upload them. Initially, the uploads will be through Canvas. I have the Canvas shell ready to go and will publish it before it is needed. The upload mechanism may change as I experiment, but I will keep you informed of changes.
- Lab assignments will look like homework assignments, except that everything will involve SPICE. The exercises will probably be more in-depth than a regular homework SPICE problem. You will do the SPICE assignments and upload them by the due date, again through Canvas initially.
- Quizzes will be “semi-asynchronous” (semi-synchronous?) initially. I’ll explain in more detail tomorrow, but the basic idea is that you pick that day that you want to do a quiz. On that day I will send it to you, you will have some time to do the work, and then send it back. This is where I will be doing the most experimentation. I hope to move to completely asynchronous quiz taking, but the form will depend on the results from the first few quizzes.
- Exam 2 will be completely synchronous, in that we will all work it at exactly the same time. In the old schedule, Exam 2 was set for Friday, Apr. 3 at 4:10 p.m. Well, life is hard enough already that we don’t need to be ruining our Friday evenings. (Although, what are going to be doing on Friday evening these days, anyway?) I propose that the we move Exam 2 to Thursday, Apr. 2 at 3:00 p.m. with a completion time of 3 hours. (It will still designed as a one-hour exam, though.) At that time, I will send out a mass email to everyone with different versions of exam. You work it, scan it, and send it back by 6:00 p.m. (All times CDT — those of you in other locales will need to adjust your times accordingly.) If there is a great outcry that the Thursday time does not work, then we will revert to the Friday at 4:00 p.m. time slot — I think that I can claim that as “our” time. We will see how things go over the next few weeks, and then determine the format of the third exam.
Whew! I’ll have more info tomorrow, including the revised “module list”.
Stay healthy everyone!
Mar 11, 2020
Due to the impending shift to on-line only instruction (as discussed in class yesterday):
- Friday's class is canceled. I had planned a couple of fun things for tomorrow, but those are not essential. If you can go home early, do it. (See below.)
- Before you leave town, turn in HW set 7, which was supposed to be due at class time on Friday. Bring it to my office -- 335 Durham. I will be in my office from 10:00 till 2:00 on both Thursday and Friday. If I am not in my office when you come by, then put in the box that I will leave outside my door. (Or slide it under the door.)
- Finish any pending lab work before you leave. That means that if you have lab on Thursday or Friday, you should go to lab and get the work done. The report for Lab 6 should be submitted during the week of Mar. 23 at your normal lab time. You will have to submit it to your TAs via email — send it directly to them, not to me. If you have not demonstrated your circuit for the first design project, then get something done and demonstrate it to a TA before you leave. You can go to the Thursday or Friday sections to show your project to those TAs (who will then relay the information to your regular TA) or make arrangements with your regular TA for a demo sometime before 5:00 p.m. on Friday. Then finish the project report and submit via email to your regular TA during the week of Mar. 23.
- For the most part, "lecture" will consist of simply reading the notes that I would e have discussed during our normal class times. I may experiment with other on-line means for presenting information, but my notes have always been our standard way of transferring information, and that will continue.
- We will continue having a two (or three) quizzes every week. I would like to continue with a "non-paper" version of the types of quizzes we have been doing all semester, but that may not be possible. I will investigate means for doing handling the quizzes, and let you know before Mar. 23 how we will proceed. If you any of you have had good experiences with on-line quizzes that you think might be useful for us, please let me know.
- We will continue having weekly homework problems for the remainder of the semester. You will need to write these out, make a good pdf of your work, and then upload it to a place where the graders can access them. I will figure out the means we will use for submitting the homework, but it definitely will not be by email. Possibilities are Canvas, Google docs, carrier pigeons, or Vulcan mind melds. Again, I will let you know the details by Mar. 23. Note that making a "good pdf" does not mean "take a photograph of each page". If you are doing your work with pencil and paper, then use a hardware scanner or a scanner app on your phone to make a good image of your work. Alternatively you can do your work on a tablet or in a word processor and then send a pdf of the file.
- While we are on hiatus, there will be no labs. This is unfortunate, but there is no practical alternative. We will replace lab exercises with SPICE simulations — obviously not the equivalent of real hands-on work with circuits, but better than nothing. In some sense, SPICE exercises will be another form of homework. The current lab descriptions will be revised so that the basic work can be done in SPICE. Each week, you will do the do the SPICE simulations, collect together the results in the form of a short lab report, and upload the report for the TAs to read and grade. In principle, you could continue to collaborate with the lab partner that you have been working with all semester, but, in this time of isolation, it will probably be easier to just work on your own. Be sure that you have a copy of SPICE (LTspice or PSPICE) that you can use on a computer in your quarantine chamber.
- Since I can no longer make announcements at lecture time, the class web site to will become even more important for providing information to the entire class. I will probably post updates every day — be sure to check frequently.
- At the moment, I do not plan to provide any on-line office hours. Even when we are not isolated, the number of people who actually come to office hours is quite small, so not having office hours won't even be noticed by the vast majority of you. Email will be probably be the most useful way to ask and answer questions. I do plan to set up a Slack channel for the class — you should get an invite in the the next day or two. You can choose to join or not. (I don't think that you will be missing much if you choose not to join — I will never make a general announcement on Slack that is not also on the web site.) You can use Slack to ask questions, either in the general discussion or as private message to me, and I will respond in kind. If, on some occasion, you would like to have a more interactive discussion, we can use FaceTime, or Skype, or Zoom, or one of the 10,000 other tools for on-line meetings — just let me know, and I will set something up with you. However, I really doubt that there will be much benefit to having a "meeting" where all of us get on-line simultaneously to have some sort of massive group discussion. Perhaps I am wrong about that, and I will rely on you to educate me.
- This is new territory for all us, and there will certainly be some inconveniences in the weeks ahead. We all need to be patient and respectful. As I said in class, every problem that we encounter in life offers possible opportunities. The pandemic shut down gives us a chance to learn and try out new things that may remain useful after life has returned to normal.
- Stay healthy. Maybe I'll see you on the other side of Covid-19!
Mar 10, 2020
The remaining two problems for homework set 7 are on the web site. The set is complete. The due date is Fri, Mar 13.
Mar 4, 2020
The schedule has been updated to reflect current events. The most immediate thing to note is that there will be a quiz on Wednesday on linear oscillators. Basically, it will have a couple of simple Wien bridge calculations. This was announced in class on Monday, but I want to make sure that everyone is aware. If you haven't already, try do some practice problems beforehand.
Mar 3, 2020
Update: I've put together a practice problem script for Wien-bridge oscillators. Take a look if you have time. The quiz tomorrow will consist of a couple of Wien-bridge questions — the practice problem gizmo may be very instructive.
In class yesterday, we mentioned the Wien-bridge oscillator circuit that was the starting point for the Hewlett-Packard company. (And hence the starting point for Silicon Valley). Here is brief history of the events and the short Wikidpedia description of the circuit.
We also mentioned the importance of clocks to navigation, and the effort to find good ways to determine longitude during ocean voyages in the 1700s. The book Longitude: The True Story of the Lone Genius Who Solved the Greatest Scientific Problem of His Time by Dava Sobel gives an interesting history of clock-maker John Harrison's efforts to solve the vexing navigational problem.
Mar 2, 2020
As discussed in class today, if you feel that you need more time to do a good job with the filter design projects, you can have an extension on the deadline for demonstrating your working circuit. Talk to your TAs to make sure that the know that you will be using some extra time. Of course, if you already having a properly working circuit, you should demo it this week in lab.
The second-order active filter notes have been updated with more examples and SPICE simulations for the various circuits. If you are still working to complete the first project, you might want to have a look at the revised notes — there might some info that will help you complete your design.
Feb 28, 2020
The original description for homework problem F9 contained a typo regarding transfer function T1. The correct ratio is T1 = V1/Vi. The problem description has been corrected.
Here are the solutions to the problems of Exam 1.
Feb 25, 2020
Lab 4 has been revised somewhat — no harder or easier, but with some parts modified a bit.
The four problems for HW set 5 are available.
Feb 24, 2020
Please note — no quiz today. There will be "real" op amp quizzes on Wednesday and Friday.
Feb 21, 2020
Feb 20, 2020
Also, I've posted solutions for homework set 4. If time permits, I will do some of the others as well.
Feb 20, 2020
I've built a new practice-problem script to help you learn to how to compute magnitude and phase from various 1-st order and 2-nd order transfer functions. Here is the link: calculating magnitude and phase. Hopefully, doing these will help you gain confidence in doing complex number calculations with transfer functions. As always when using a newly developed tool, beware of typos. (Unfortunately, I do not have a large software test staff.)
However, I suspect that, for some people, more practice exercises will not help, because the real problem in is not knowing to manipulate complex numbers in polar form in the first place. If that's the case for you, then you need to go back to the 201 notes and (re-)learn how to work with complex numbers in both real/imaginary and magnitude/phase form.
Feb 19, 2020
Here is the solution to last year's exam.
Feb 19, 2020
Schedule update: I had said that we should probably have a quiz today, but I've changed my mind about that. No quiz today. The next quiz will be on Monday.
As requested: Exam review session tonight — 8:00 p.m. in Hoover 1227.
Feb 17, 2020
I've added one more project to the list of options — a notch filter design. I've also clarified the due dates for the project demonstration and reports.
Feb 15, 2020
Here is a copy of Exam 1 from Spring 2019. Use it as you see fit.
Feb 13, 2020
Rather than send out the crappy notes that I wrote in class yesterday, I've written up a few pages with examples of how to analyze ladder circuits. Have a look if you are still struggling with those. Even if you have mastered ladder circuits, you might want to look at the last page of those notes to see how buffer amps might make life easier.
Feb 11, 2020
A slight change in the schedule – no quiz on Wednesday. Instead, we will have second-order filter quizzes on Friday and Monday.
Feb 10, 2020
The description for Lab 3 has been updated — make sure that you are using the newer version.
Jan 29, 2020
Homework problem L5 and L6 have been posted. These complete homework set 2.
Jan 20, 2020
In case you hadn't noticed, the 6 op amp homework problems are all available.
For those of you who are interested in the Audio/Arduino clubs, we will have the first meeting next Monday (Jan. 27) at 5:30 p.m. Location to be announced.
Jan 17, 2020
Due to the deteriorating weather, we will not have class today.
We will continue with scheduled activities next week. Since the op amp material is review, I will not cover the second half of those notes in class — you should read those on your own to make sure that you are up to speed on basic op amp topics. If you have questions about those topics, ask them when we meet for lecture next time. Once we dispense with the op amp questions, I will begin discussing Laplace techniques for circuits.
Jan 13, 2020
First-day intro slides
Two lists to read through at the beginning of EE 230:
Dec 18, 2019
This website will be updated over the next few weeks, getting ready for next semester.