Saturday, December 12, 2009

Fall Quarter

Unfortunately, this is one of those blog posts where nobody knows what I'm talking about, so feel free to not waste your time trying to read it.

Anyway, I took three engineering classes for Fall 2009 Quarter; EE 341 - Discrete Time Linear Systems, EE 473 - Analog Integrated Circuit Design, and EE 476 - Digital Integrated Circuit Design. In EE 341 - Discrete Time Linear Systems, you pretty much cover many of the principles needed for most audio, image, and video processing. The course pretty focuses on applications of Z-transforms (which are Laplace Transforms for discrete signals), Discrete Fourier Transforms, Discrete Time Fourier Transforms, and Discrete Time Fourier Series.

In EE 473 - Analog Integrated Circuit Design, you essentially learn how to create amplifiers using 23o nm CMOS technology. For our final project, we developed an 80-dB fully-differential amplifier with several design specifications for input and output capacitance, phase margin, power consumption, output swing, and unity-gain frequency. We used a folded-cascode topology with a common-source second stage, biased with low-voltage cascode current mirrors. The circuit also implemented common-mode feedback, which we just included as a couple resistors and an ideal op-amp, and also Miller compensation. Unfortunately, we only had one week to do the project, and we ran into a pretty time-consuming problem, but eventually we got something that met most of the specifications after a rather frustrating overnighter. We could have done better if we had a little more time.



In EE 476 - Digital Integrated Circuit Design, we worked on a 45 nm CMOS process. Our final project was to design an arbiter circuit in behavioral Verilog, then using software tools to convert the Verilog code into logic gates. We drew out a series of 9 logiItalicc gate standard cells, with which we actually drew out all the transistors and connecting metal layers, and used an automated process to convert the logic gates into a layout using standard cells. Below is our resulting integrated circuit, which measures only 15 x 15 μmFont size², consists of 91 standard cells, for a total 362 transistors.



Here is our design for just one of the standard cells, the D-Flip Flop, which measures 1.235 x 3.23 μm². A Flip-Flop is essentially a memory storage cell, which holds one bit of information.


D Flip-Flop Schematic

Layout of the D Flip-Flop

It would take a long time to explain what's going on here. All the blue rectangles are the lowest metal layer, the pink rectangles are the second metal layer, all the red rectangles are polysilicon (used for the gates for transistors), the W's indicate the p- or n-doped wells, the triangles indicate p- or n- heavily doped regions. The layout image directly translates to the schematic above. Each of the colors represents a different mask during the manufacturing process. Since it costs well over a million dollars to manufacture an integrated circuit, we mostly relied on simulation software to test our design.

Most of the work in this quarter was learning how to use the Virtuoso design suite to design and simulate our circuits. Unfortunately, the University of Washington file servers were running extremely slow, and so we wasted a lot of time waiting for the mouse to catch up. It was also frustrating, since there were three classes all trying to use the University of Washington's only 20 Linux computers at the same time.

Saturday, December 5, 2009

Roland C-330 Home Organ

I need to introduce you to the newest member of my family, the Roland C-330 Home Organ. I'm officially the first one in Seattle to actually own one. My Dad and I went down to pick it up from the Rodgers factory in Hillsboro, Oregon over Thanksgiving weekend, and we were quite confident that it would fit in the Toyota RAV, since the Rodgers salesperson we met with earlier mentioned that it was small enough to fit in a car. As we figured out, JUST BARELY. We had to remove all the packaging. After getting it back to my apartment, I set it up and started to crank it up to see how loud it would go. Less than 30 minutes into playing it for the first time, somebody knocked on the door and complained I was being too loud... Oh, well, I guess that's why I got head phones!




Below, I made a few recordings in my free time, to illustrate some of the sounds of this magnificent instrument. I will post more as I make them. The recordings came out perfect quality, and may have created some background noise and lost a little bit of high-frequency information as I converted them to MP3 format, so they sound a little different. They're not perfect, but they should at least give you an idea why I fell in love with this instrument. I recorded using the Line-in audio port on my Powerbook G4 using SoundStudio3.

O Lamm Gottes, unschuldig (O Innocent Lamb of God), J. S. Bach BWV 1095 - Uses mostly flute stops


Prelude and Fugue in G Major, J. S. Bach BWV 557 - Set with a high amount of reverb, to mimic a cathedral sound


Nun komm, der Heiden Heiland (Come Now, Savior of the Heathen), J. S. Bach BWV 599


Herr Christ, der einge Gottes-Sohn (Lord Christ, the only Son of God), J. S. Bach BWV 601 - Illustrates full organ sound

Thursday, September 10, 2009

Looking for organs

Hello, everyone!

Yesterday, my Dad, sister Diane, and I went down to Oregon to visit Rodgers Instruments LLC. Rodgers of course is the company that produced the organs for Faith Presbyterian Church. I have been having in my mind to pick up a good home practice organ, since I was losing valuable sleep on Saturday nights practicing for church service on Sundays, usually hindering my ability to stay alert in the service the next day.

I had a couple major criteria looking for an organ. Firstly, it would have to be compact and easy to move around, since there isn't much space in the apartment to fit it. Also, I wanted something that didn't sound like an electronic instrument, and had a good variety of instruments. After wasting time on Craigslist and being terribly disappointed by the terrible selection at Prossers Piano and Organ, began looking into the major Classic Organ companies (Johannus, Allen, and Rodgers), and actually got to go preview the Johannus 37 SE at somebody's apartment in downtown Seattle. Johannus has been having a half-off sale for sometime, so some of their organs were attractively priced, including the Opus 7 I was looking at. Frankly, I wasn't impressed with the Johannus organ tones, which still sounded very electronic to me, especially the reeds. To me, there really is no comparison with the Rodgers organ sounds.

I discovered the Roland/Rodgers C-330 organ while surfing online, which just started selling a week ago and there has been a wild internet buzz for a while. Roland is coming out with a Classic series, where they are trying to make authentic-sounding harpsichords, pianos, and organs for homes. After looking into this organ a little bit, I discovered that it is a very special piece of equipment. For starters, it had packed in it over 100 different Rodgers pipe sounds. The organ had excellent acoustics for what I wanted. And the tone quality was phenomenal (hear samples here).

Here is a photo of me trying out the Roland/Rodgers C-330 at the Rodgers plant in Hillsboro, Oregon:



Tuesday, July 21, 2009

New Apartment

Hello, everyone;

Yet again, I need to apologize for not blogging in a really long time. Time just tends to fly between posts, and being in Engineering, it feels like I can never find any leisure time to update.

I just moved into my new apartment in the last week. I promised I would upload some photos of my new place. I decided to move off campus for several reasons. One of the primary reasons is that the UW Housing and Food Services decided on a new rule that if you live in the residence halls, you have to subscribe to the university meal plan. The food really isn't that great, and it is way overpriced. To illustrate, for a simple breakfast of a waffle, scrambled eggs, bacon, and orange juice, you can be charged over $10. I found myself in the habit of eating out every day, since it was cheaper and higher quality than provided by the HFS.

So after a week of searching, a fellow Electrical Enginner colleague and I found a good 2 bedroom apartment at Travigne Apartments. Our place is located on 11th Ave in the University District. After spending a week of searching, we decided on this apartment, since it is unusually high quality for the low price. I'm paying just a little more than I was for the residence halls, but now I am able to cook for myself, plus it is a significant increase in quality.



Main entrance



Our apartment is the one with the balcony on the top floor.


Inside the lobby area


Coming out of the elevator, our apartment is the first door on the left.


My futon, which until just recently, served as a bed rather than a couch. I got the blanket when I was on my first deployment with the USAF to Qatar.


Bookshelf containing the textbooks my roomate and I have been accumulating over the years, as well as leisure reading.


Looking outside to the balcony


Looking down from off the balcony.


My roomate's grill, so we could eat lots of barbecue.


Kitchen area


The coffee pot, which is now used primarily for making tea since I quit coffee.


My desk and dresser area

My bed.


The apartment opens up rooftop access to the residents.


Views from the roof of the apartments. Blessed Sacrament Church (catholic), and a view of downtown Seattle and space needle.


Right now, I'm taking the Summer off from school. I began the Summer Quarter out taking a full load of classes, although I began to have really bad anxiety attacks for some reason while performing coursework. I think the main causes for this anxiety are because for Spring Quarter, I was pushing myself too hard, pulling too many overnight study sessions, and drinking coffee. This combination can make you really go crazy after a while. A couple weeks ago, I decided to quit drinking coffee, because I think that was the main culprit. After I quit coffee and went through a period of withdraw, I felt a lot better.

Now that I'm off, I intend to catch up with a lot of things that due to my course load, I never really could find much time to do: reading, learning new music, exercising, research employment opportunities and organizing unsorted computer files and stacks of papers. I'll also be looking for Summer jobs painting and doing yard work.

I intend to be complete with all my coursework after Spring Quarter next year, and I will have a Bachelor's of Science in Electrical Engineering. This next year is going to be my toughest year, since from the looks of it, I have a capstone design class every quarter. I'm intending on getting completing at least two areas of knowledge in the next year in Embedded Systems and Analog Circuit design, and if I feel like it's not too much, attempt VLSI (Very Large-Scale Integration).

A couple weeks ago, I got called last minute to put together music last minute for a wedding. Due to a misunderstanding, the organist who was expected to do the wedding wasn't in town for that day, so I was called up as a last resort a week before the wedding. I pretty much chose out all the music, and I got together with a good friend who plays the violin, and we put together a prelude. I recycled pieces I had used for another wedding a couple years ago on Bremerton Naval Base, and tried a couple other pieces that I used for Resurrection that I thought would work. Overall, I got very positive response for the music, so I was glad I could help out and remove that burden from the family.

Speaking of weddings, congratulations to my sister Rachel for her recent engagement to Alex! She is getting married on January 2 at Faith Presbyterian Church. May God shower his blessings on both of you.



In September, my Dad and I are once again hiking the Wonderland Trail (110 mile hike around Mt. Rainier), and we're planning to spend a week doing that, so I'm trying to put together camping trips and day hike trips to make sure I'm in shape for that. Later this week, I will be at Eagle Creek for two days with my dad and some good friends.

Anyway, that is my spiel for the time being. I'll try to update more often, although when classes pick up again, I really won't have any time, so I'll apologize in advance for not posting in so long, and I hope you understand.

Wednesday, January 14, 2009

Update

I just happened to notice that my blog was horribly updated, and my last post was from back in August. Last year I took a web programming class to motivate me to create a really decked out web page, but it only taught me that it's way too time consuming and too much effort. So here I am, using Blogger.com still.

I'm now on Skype, which seems like a really nifty online phone service. If you want, you can reach me with my user name, jfeucht82, and I'll try to leave it on as much as possible. My philosophy is that I should pay as little on telephone communication as humanly possible. If you've ever tried calling me, you've probably noticed that I rarely carry my phone on me wherever I go, and I respond to email a lot faster than I do via telephone. I currently own the cheapest AT&T pay-as-you-go phones I could possibly get, and it's malfunctioning because the ringer doesn't work anymore for some reason.

I was just looking through my online degree audit (or a listing of classes you still need to graduate), and I figured if I take the right classes, I might be able to graduate the end of Spring Quarter in June. I've been following mostly the program requirements of VLSI (Very Large Scale Integrated) Circuits, although the final courses I would need for that program aren't offered until the Summer or Fall quarter. On the other hand, I could take two engineering courses next quarter, and be done with the program requirements for Embedded Computing Systems, which is another field I have quite a bit of interest in. And I kind of want to exhaust the funds in my GI bill before I get out of the University of Washington, and I have funds to cover me through Fall Quarter this year, if I take classes over the summer.

So that's something I'm going to have to start thinking about. I've been prettying up my résumé and cover letter for possible internships and jobs coming up, and I have some career fairs to attend...

This quarter, I'm taking two engineering courses, and a writing course (I have to take two technical writing courses). I'm also taking my first 400-level UW course, E E 471 Computer Design and Organization. This class seems like it's going to be quite a bit of work. We're learning how to design our own microprocessor using Verilog, which is a computer language designed specifically for modeling digital circuits. Over the course of four lab assignments, we will design critical components of the processor. The class pretty much deals with figuring out how a processor processes machine code, and how all the components in a processor interact with each other.

The other engineering course I'm taking is E E 332 Devices and Circuits II, which is a continuation of an engineering class I took last quarter. This class deals primarily with designing circuits with BJTs (Bipolar Junction Transistors), which are pretty much electronic parts that amplify signals. Our final design project is to design and build an audio amplifier.

Anyway, that's all I have to say for now. Sometime in the near future, I might come up with something that's actually interesting to talk about and blog about it, but as for now, if you're too bored, you can check out my AC to DC in my previous post and marvel at how incredibly interesting it is.

An AC to DC Converter

In one of my classes, E E 331 Devices and Circuits I, our final project was to build an AC to DC converter. Our design specifications were to take a 10 Vpp 60 Hz DC input from a center-tap transformer and have an adjustable 10 V to 20 V DC output. It was expected to have output noise of maximum 100 mV, and able to deliver 1 mA current for all voltage settings. Also, we were graded on how cheap the circuit was to build.



Above is a block diagram of our design. The circuit works by rectifying an AC input, creating a high frequency square wave, and using that wave to drive a boost converter to amplify the rectified input signal to a level dictated by a differential amplifier you could control using a potentiometer.



And above is the circuit schematic as viewed in PSPICE schematic and simulation software. The circuit was designed mostly on computer, then built later when the simulated circuit met specifications. The square wave was provided by a 555 timer, and the differential amplifier was built using a LM741 operational amplifier. The amplifier compares the voltage at the anode of a 5 V zener diode with the output voltage, and increases its output voltage when the output voltage falls too low, and decreases its output when the output voltage gets too high. This feedback system maintains a constant output voltage, which is calibrated using a network of resisters to operate within the specified range.



Above is the circuit built on a breadboard. The total cost of all the electrical components is a little under $8. Our design had barely any noise in the output, and it met all performance requirements within a narrow error margin.