Useful functions to do LaPlace and Inverse LaPlace on your TI-89.
http://www.ticalc.org/pub/89/basic/math/

 

Remember to test the functions. When I was using degrees for angles, the program gives weird answers. I have to change the mode to radian mode to give the right answers.

 

inv_laplace.zip

42k

04-04-30

Inverse Laplace Transformation v 1.04 Returns the inverse Laplace transformation of a f(s) function. Bugs fixed.

Professor Pinto,

 

I am a 4.0GPA student, and I have been a tutor for an introduction circuit class. If there is only one thing I am good at, and that is I am good at making friends. I talked to enough people ,and this is my humble comments about the ee40 class.

 

In response to your email request, I would like you to know people who take EE40 have very different purposes. There are 4 types of people, and they should expect different styles of lectures.

 

The first type, or the main type are students who are EECS major with different options (like option I to option V). I know 8 of these kind of people, and I believe this is the main group of students in the ee40 classroom. This type of students like the interesting electrical presentation during the lectures, and I am one of them. I notice there are a lot of interseting things in the lecture like the microwave, the Am radio, and the analog-to-digital circuit that are very interesting and out of the book. I like those presentations. I am the type of people who determined to be an engineer the rest of my life. Therefore I don't mind spending extra time reading the book after class. However, I have friends who are taking 2 or 3 classes during summer, and what they complain is they don't understand the lecture because half of the lecture time is used to talk about things out of the book and they don't have time to read the book to get the basic ideas of the subject.

 

The second type are people who have worked for many years in the industry, for example they worked the computer science field, and after the " dot com" period they decided to study more about electronics. I know 2 people in the class are this kind of people. One of them is a professional programmer who worked for companies many years, and his programming ability is amazing. He won scholarships and programming contests and became a technical director of a programming firm. He told me he saved so much money to study at Berkeley, and all he wants is to get a diploma and get a high paying job. He told me explicitly how he was disappointed by the first class (EE40) he had at Berkeley. He was expecting a clear and well constructed lecture that makes him understand. Instead he feels like the lectures sometimes talk about the first thing and then jump to second thing, and the first and the second things are not related. He said,"the lectures are just not well organized." I think he likes more step by step introduction of the subject instead of the interesting topics that was presented.

 

The third type are people who are not electrical engineering major. I have a friend from bioengineering major, and ee40 is the only electrical engineering class he will ever take. I have friends from civil engineering and mechanical engineering wanted to take ee40 because they want to know a little bit about circuit designs and analysis. They are fascinated by the electrical stuff (like cell phone and computer) that we have nowadays and want to learn some basics about electronics. Similarly, this type of people only take introduction class like ee40. My friend actually told me he doesn't follow the lectures, and he spent a lot of time reading the book to get the idea, and after he got the ideas from the book, he attend the lecture and see things very differnt than those from the book. He complained he spent lots of hours doing HW2 and got a very complicated answer also. From my friend, I realize many people didn't take any introduction circuit class like I did. In fact, I took the introduction circuit class and I have a certain level of understanding on circuits before I take ee40. I was a paid tutor for tutoring others about the introduction circuit class. However, a lot of students in this ee40 are encountering the circuit elements in the ee40 the very first time. Everything on the blackboard of the ee40 lectures are weird to them. When I was fascinated by the use of op amp during the lecture, my friend was feeling op amp is a weird element that he has never seen before. In simple words, people are confused because the circuit elements in ee40 are not the microwave or the cell phone that they have seen, and they are confused and they couldn't find further reading about the lecture on some of the topics.

 

The fourth type of people are those who are only at Berkeley for the summer session. I know 3 of these kind of people. They are either from electrical engineering major of another country, or maybe even from high school in the us. The friends I know from another country told me that they don't have microelectronics (ee40) as a class in their country, and they are here to experience the American teaching style and to see the differences and similiarities of electrical engineering teaching. I believe they want a more standard and easy to understand lecture instead of challenging projects or homework that they cannot be sure if they get the right answer. Summer session is shorter than usual, and the pace is fast. Sometimes we may not get the right idea if we don't have the chance to talk to others and make sure we get the right ideas. I have the experiences of not knowing the properties of linear circuits and non-linear circuits, but my friend corrected my understandings.

 

Some other comments about the labs. During the labs, we often are required to use spice to stimulate circuits. I have spent a lot of time playing with pspice, and I get pretty familiar with pspice now. I have installed different versions of spice in my computer(hspice, two version of pspice, and 5spice). I notice many students in the class uses 5spice, others use pspice, and a few use linux based spice. I used all of the spice, and I agree 5spice is very easy to use. However, I choose to get familiar with pspice because the textbook have a detail step-by-step tutorial session (Appendix D) teaching us how to use pspice, and the textbook used examples from the chapters to do the pspice stimulation. The second reason using pspice is that the EE140 lab room only has pspice on the computers, and 5spice is not allowed to be installed due to computer restrictions. Friends I know who are good at linux spice and 5spice can only draw their circuit by hand and use notepad to record their data. At the same time, every lab I do I pull out my circuit generated by pspice capture, and stimulate my circuit during the lab. I usually finish my labs faster than any others, and I got full credits for my reports. The final thing to mention is that the textbook provided a version of pspice that has all the libraries we need for this class, I didn't have to look around for parts. I am getting better at hspice because I know I have to typing the circuit into the program using hspice is faster, and is more close to the industrial standard.

 

Good Luck.