## PHYS345 Electricity and Electronics

Student Suggestions and My Responses

My responses are italicized. I sometimes edit slightly, truncate, or abridge the submissions. Listed in reverse chronological order.

1. I know that I and at least several others have been studying for exams and have not had sufficient time to put toward this week's homework. I was hoping that it would be possible to delay the deadline for the homework. Thanks. [11/17 1:32am]

See below...

2. Did you say last week that it is OK for us to turn in our homework up until the review session on wednesday night?  I wasn't sure, and confusing rumors are going around about it.  I am having some trouble completing this homework section due to an exam in Mechanics of Solids.  So having it due on Wednesday would help. If not...then I will manage.  Thank you! [11/16 9:16pm]

I have been asked to clarify the homework due date issue. I have recently been cited as having stated that homework can be turned in up to the time I start the Wednesday evening review session. I sort of recall saying that, so by all means prepare for your exam and catch up with your homework later tomorrow. See you in class and good luck on your exam. [11/16 10:06pm]

3. I am really having a hard time constructing this IC for the prime number counter. I have made it over 4 times from scratch, using the NAND only circuit we made on EWB. I am not sure if there is something wrong with EWB, the way the voltage sources and grounds are connected, or my selection of chips. I am using a Quad D-flip-flop (with a clr connection; should this be connected?), and 3 quad 2-input NAND chips. The regular NAND configuration we did prior to the IC worked fine, but all I get for the D's now is a constantly lit indicator (if i ground the Vcc, all the indicators go out). It is becoming very frustrating. Please give me any help you can. Thanks. [11/12]

Sounds like you may be having troulble with the set or clear function of the flip-flop. Generally every input of a flip-flop has to be tied to either +Vcc or ground. [11/12]

I don't exactly understand what to do with the clear input. We don't have it on our Karnaugh maps, and its not used in the example on the Internet for the 2-bit IC counter. And if you mean everything has to be tied to ground or Vcc, does that mean I have to hardwire each input, or can't I just hook them up through the IC chip, which has a Vcc input and group recepticle? [11/12]

Check the online data sheets! [11/12]

I actually had a suggestion about the switching-OR-to-NAND predicament. When I did the lab, I finished the entire first part with ANDs and ORs. I then copied it and dragged it down to start the second part. I just dragged down some NANDs and placed them right next to the ORs and ANDs. I clicked at the input terminals of the old gates, where the wiring was already "right," and one-by-one I connected the wires to the same input of the NAND by dragging the heads of the wires. After I had filled the NAND with the inputs from the OR (this works for ANDs also), I just deleted the old gate and plugged the new one into the gap the old one left. If I messed up somewhere and was unsure what to hook up, I still had the original above as a reference. Simple, painless, no need for nodes (which can be a pain hooking up to sometimes), and although it took some time, was error-free! What more could you ask? All right, a Solve-the-entire-problem gate would be nice too... [11/12]

Thanks for the suggestion! [11/12]

4. I was browsing through the technology articles on the NYTimes online and saw an article from July 23 that directly correlated to your transistor lecture from thursday. It is titled "Behind the curtain in digital Oz, the simple chip." It mentions Moore's law also. I though the rest of the class might be interested in reading this article also. Maybe you could add it to the archive you have on your web page. [11/12]

Thanks! I added it to the bottom of the recent class page on that topic. [11/12]

5. Today's class helped to explain the homework that was due today. However, I know that I and many other students came to class today clueless about the homework that was due. When I first looked at the homework on Sunday night, I honestly thought to myself that it was material we hadn't covered yet. I figured you had posted it to the web as our next assignment, but that you hadn't really explained it yet. As for Thursday's lecture, I felt that I understood it fine and I followed everything you were saying. But I still did not think that Thursday's lecture applied to the homework problems. In class today, another student leaned over and whispered to me, "If I had heard this last week, I might have been able to understand the homework.", so I know I'm not alone. Anyway, I think that it would benefit a great deal of students if you would allow us to redo the homework that was due today and resubmit it. I think you're going to find that many of the students turned in homework that really isn't even worth grading. Now I could be wrong, everyone could have been just agreeing with me to make me feel better (and I wouldn't put it past them) but I still wanted to address the issue in hopes that you would consider my suggestion. [11/10]

I accept this recommendation. I will continue to accept homework submissions up to the review session Wednesday at 6pm. You may place them in my mailbox or bring them to my office. [11/10]

6. In looking over the chapter 8 problems and notes we took on the subject, I feel like we were thrown into the advanced concepts without a basic overview (understanding) of the bulk of the material. This isn't specific to amplifiers, but I feel especially unsettled on that subject.

The last lecture on binary was great, that was a nice pace with all the basics outlined, leaving room for us to do some learning on our own and feel confident in our basics. [10/26]

Sorry about the confusion regarding amplifiers. I have added a summary diagram called Amplifiers in Use that may serve as a guide to understanding the bulk of Ch.8. I will approach the material differently next time. I aspire to have all classes be as effective as the class on binary, but it doesn't always happen, especially the first time a course is taught. Not that I'm making excuses... [10/30]

7. Could you include more simple problems in the homeworks? I feel that in some of the more complex examples, we dive into some tough questions that don't reinforce the basic ideas and I get confused. The tougher ones are fine if I understand the basic concepts but sometimes that doesn't happen. [10/22]

I am reluctant to begin assigning a higher load of problems at this point in the semester, even if they are simpler. In future semesters I may modify the homework schedule along your suggesion.

The so-called drill problems in our textbook (designated by D at the end of the chapter) are available with answers. I would recommend that you scan through those problems and attempt a few that incorporate the new or troubling concepts. I am happy to review any such work with you during office hours or in the Wednesday evening review session. [10/23]

8. I think you have been extremely patient with the student suggestions you have been getting. I read what my classmates say every now and again, but lately the suggestions that were posted seem like a bunch of petty whining from some students who either don't want to take the time to prepare for lecture or have zero motivation to gain the skills they need to do the work without it being expressly assigned. I am disappointed in their attutudes toward education... [10/16]

I held this note a week before deciding to post a truncated version of it. I do not wish these recent notes to turn into a point-counterpoint escalation, but I have not refrained from posting any submissions yet this semester (that I recall), so here they are... [10/23]

9. I can fully apreciate that you have deterred from the computer and started doing problems on the board. However, there is one slight problem with this. I don't take it against my fellow classmates that are generally "excited" by this class. It's just that to some of us, this stuff is not coming easy.

It has gotten hard to grasp some of the concepts. I come to class all of the time and even spend an extra amount of time reading the material over 3 or 4 times. It's just that class is a great time to get you to do problems so that we can understand what these concepts mean. We know that it is not always chug and plug.

It's just that some students are always answering your questions, and not giving any of us a chance to let things sink in. I know that classes can not necessarily go slow, but it would be nice to give some of us a chance. It would be nice to see you finish a problem without a student blurting out the answers for you. Some of us need to see things worked out before we can fully understand it.

The problem session on Wednesday is great, but some of us have other activities (sports, clubs, et al.) that take up our evenings and meeting at [that] time is impossible. Thank you. [10/15]

I'll take it under advisement, as they say... [10/15]

10. First off, I must agree with my classmates in stating that our book isn't worth the paper it's printed on. The examples don't cover the normal problems, let alone the "computer aided" ones. Specifically, I'm unhappy with 6.11, 6.12, and 6.13. I hope you reconsider grading these problems, even with the extra time you gave us. All it did was extend the time that I stared at the page by a few days. Also, I don't know how to use maple, or mathcad, or any other computer math program. I think everyone would agree that we have enough to handle with our courseload and subject material without struggling with some arcane computer program. If you'd like to take us to a computer lab and teach us the skills necessary to complete any computer aided assignments, then by all means, but otherwise, I'd appreciate it if we could keep our work confined to pencil and paper. Thanks. [10/11]

OK, I hear your frustration with the process. I may have overestimated the extent to which students were using Maple from their experience in the calculus program here. To be honest, I assigned these 3 problems to check your resourcefulness and facility in using software plotting programs. I now have the information that I was looking for, that the student access to and use of plotting programs is still very mixed.

The availability of powerful computers and software is changing the practice of engineering. My goal is to bring this power into the classroom. What I will most likely do next time this course is offered is to order student versions of MathCAD (and Electronics Workbench) for student purchase at the bookstore and schedule separate training sessions for those interested or inexperienced. The days of pencil and paper problems should have ended ten years ago -- note that I am not still using my sliderule... [10/14]

11. I was wondering if there is any where to get the answers to the concept checks. [10/7]

I do not post answers to the concept checks for several reasons. One reason is that a good concept check is sometimes hard to develop; I would like to continue to use the questions in future years and ready availability of answers on the web might subvert my intentions.

A second reason to keep the availability of answers to concept checks limited to the classroom is that it serves as a small incentive to have good attendance habits. This is not a problem at all this semester, but you never know...

Finally, the concept check questions stay available as a ready resource to check your thinking. If you really understand the concept, your confidence in your own answer should grow as a result. I am pleased to discuss any of the concept checks individually or at exam reviews. [10/8]

12. Is there any chance that you have any old phys208 or scen103 exams that would be useful in studying for the exam? Thank you. [10/3]

I do have exam archives for those two courses: SCEN103, PHYS208. However I am not sure how helpful they will be given that this is a seriously different course. But it would not be a bad idea to look over a few of those exams, especially for the concept check type of question! [10/5]

13. Find a different text to use for future PHYS345 classes. The one that you chose is difficult to understand. There are too many mistakes and I don't feel the examples prepare me for the homework problems. [10/2]

I will definitely be re-evaluating my selection of textbook for the next offering of PHYS345. I was also surprised that there are so many typographical errors, given that the text is in its second edition. There is a list of errata available; please let me know of additional errors that you discover.

14. Dr. Watson, keep up the good work with the website. To be able to refer back to it for notes and whatnot gives me a better understanding of the stuff we are learning. Thanks! One question about the homework though...can we simplify number D3.9 an further than it is? [9/20]

Glad to hear that the website is useful! Let me know if there are additional features that would be beneficial to your learning.

Re: D3.9, you should be able to replace everything except the 6.0 A current source with a Thevenin generator. Not sure exactly what you mean by simplify other than that, so I am not sure I have helped... [9/21]

15. I am frustrated by the inconsistency of problems in this class. One type of problem will be explained in class and in the book examples, but a totally different type of problem will be assigned in the homework. For instance, the book examples and examples done in class often use only voltage sources. Then, we are given problems with current sources in the homework, and we don't have experience in dealing with those. Would you please make an effort to do sample problems similar to what we'll need to do in the homework? Thanks. [9/16]

I am a big advocate of testing your understanding of the concepts with problems that send you to previously unexplored areas. I realize that you face frustation when this is the case, but these are the real learning opportunities as you engage the material. That having been said, I will try to incorporate more current sources into my examples. I will start class today with a circuit involving mixed sources to make it up to you... (See the text's P3.8) [9/17]

16. I like the website alot. I think that it is a very good learning tool. It enables me to focus all of my attention on the lecture instead of on my notes. If I miss something in my notes, I can just get it from the web. Please continue with the website. Thanks. [9/13]

I plan on continuing to make as many notes available at the course website as time permits. The adjustment that I have made is how often and to what degree I present web pages during class time. Thanks for your encouragement. [9/14]

17. I understand that your objective as a professor of this university is to instruct us as best as you possibly can, but the amount of work that is required for this course is, quite frankly, scaring me. ME majors this year have 17 credits involving Mechanics of Solids, Engineering Math, Stat for Engineers, Dynamics, and your class. Each other class requires a significant amount of work also. My suggestion is that only one homework assignment per week be given. That way, we would be responsible for the one homework, the pre-lab, and the lab itself. Still a fair amount of work for one class, but definately more reasonable than two assignments per week. Thanks for your time. [9/9]

18. This semester is going to be a lot of work as it is. The way this class is set up we are doing work on Monday, a pre-lab on Tuesday and more work on Wednesday. This takes up a large portion of a week which must be divided up for several other classes. It would help if all the HW was due on one day, preferably Thursday. I do like the website for the class it is a helpful tool for learning. [9/9]

As I announced in class, I have adjusted the homework policy so that all homework solutions are due on Tuesday, giving you the weekend to catch up and the midweek to focus on the laboratory exercise. I will still be associating problem assignments with each class, but assignments will no longer be due on Thursdays. [9/11]

19. Your electronic way of teaching through the Internet stinks. I learn very poorly through it since none of it remains on the board and you draw no pictures or write words. You don't emphasive anything or write outlines we can follow.

You have a good textbook that will give us much practical knowledge, what we need, instead of theoretical crud we'll forget. You should use the book more. The book explains things better. [9/7]

I hope the modifications that I have made in class presentations has alleviated some of your concern. [9/11]

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Last updated Nov. 17, 1998.
Copyright George Watson, Univ. of Delaware, 1998.