Saket Vora

We’ve come a long way this week. On Monday, we hadn’t even begun the main crux of our experiment, which involves studying the adverse effects that high frequency electromagnetic interference could have on power supplies that are found in every desktop computer. Konstantin has set up something called an oscillator which uses a special kind of amplifier to output high frequency signals. More specifically, he has configured this oscillator to oscillate chaotically, or nearly chaotically. The signal that it puts out is exists in a wide band of frequencies instead of a narrow band.
For the past three or four weeks, I have been studying a power supply, trying to understand the circuity and identify places where it might be most susceptible to interference. This week we finally brought together our two aspects of this research project: I installed an RF connection and soldered it to different points on the power supply’s circuitry and then we injected signals from Konstantin’s oscillator into the power supply. We used oscilloscopes to monitor the output voltages and varied parameters in order to see what it would take for the power supply to get disrupted.

We ended up finally injecting signals on Wednesday. By that point, I felt we were a week behind schedule. You see, our final poster for the MERIT Fair (on August 11) is due the following Thursday, and our final technical report (~20 pages) is due the following Monday. This gives us precious little time to analyze our results. Wednesday and most of Thursday was difficult, because we weren’t getting any real good results. We hammered that poor power supply with up to 5 Watts of peak power, and we were just able to get some output disturbances on the range of a few hundred millivolts. While this might enough to technically say the power supply is ‘disrupting’, I was hoping to shut the thing entirely down.
I had this hunch though, after noticing the behavior of the power supply as I was testing it earlier. I wanted to try injecting the signal into a particular cable, but it was met with some skepticism. Late Thursday night, around 9pm I think, I wanted to try it regardless so I soldered the connector on and gave it a go. To my delight, the power supply shut down! I spent the next two hours systematically testing it and grabbing a lot of data.

Today we further explored what was causing the power supply to shut itself down, and did some more tests using different setups and controls to get a better picture of what was going on. It was pretty good.

This weekend is going to be tough though. I have to first sort through and organize all the data we took these past three days, as well as analyze them for trends. Then I’m going to write as much of the final report as I can (covering my parts), because much of that will feed into the poster.

I just have to get to next Monday, after we send off the final technical report to all the judges. Then we can chill a bit before the MERIT Fair.

Last weekend Greg came up from Raleigh and Donny came down from Philadelphia and we all spent the weekend together. It was a lot of fun. I got to meet friends from Greg’s high school, we ate at some fine restaurants and saw Pirates 2. Donny stayed over in College Park with me and on Sunday we drove up to Baltimore to see Fort McHenry and had dinner at this nice place Donny found behind Camden Yards.

So far this week I’ve been staying 12 to 15 hours a day in the lab. It’s been going more slowly than I would have like. Finally though, with Todd’s (the graduate student) help, at around 8pm yesterday we actually got some results. It’s not ideal (ie, the power supply isn’t shutting off or restarting) but it’s a start. Today and tomorrow will be spent acquiring data like mad, and I’ll do most of the data analysis and start the report and poster over the weekend. It’s going to be tight, but I think I can make it.

We can sleep when we’re dead, right?

Yesterday the group took a field trip out to Johns Hopkins Applied Physics Lab. It was alright. They jumped so fast into areas of their research we might find interesting that they never really explained the history of APL, the different divisions or groups that make up APL, its funding and major projects. After someone explained his work in information security, two guys came and did an extensive description of microelectronics, with a lot of examples of MEMs fabrication that they do in their clean room. It was a bit over the heads of the TREND students and heck, probably a lot of the MERIT EE students too. APL also does software simulations for the TRIDENT missile systems for submarines. Two guys led us through an energetic simulation of how a missile launch would work. It was pretty cool, but didn’t really relate to engineering or physics. Anyway.

After getting back from APL, the guys went to the China Buffet and had lunch. We all ate a bit too much. After returning to the lab, I worked at helping Kristy and Michelle and Hymin out. I really didn’t get anywhere with my stuff. I did re-visit the power supply schematic, and spent the rest of the evening working on that. I got distracted a bit with some instant messaging conversations. I got into a zone and actually linked up the two main chips on the power supply. By the time I knew it, it was 10:30pm. Time to go home!

Today, John made his return and everyone was happy. He went around to each of us and fixed our problems and got us back on track more or less. With a renewed sense of focus, I didn’t even go to lunch until 4:30pm. I stayed around at the lab until 9:30pm. I think this trend will continue, because we are about 3 days behind where we should be.

Greg is coming up on Friday and we’re gonna go walk the streets of Georgetown. Old Glory! It’s going to be great. I can’t wait.

On Saturday I took a day trip to Gettysburg, just north of the Maryland-Pennsylvania border. As students of American history know, the small town of Gettysburg was the site of the largest battle ever fought on American soil. It was the climactic battle of the Civil War and 51,000 men were killed or wounded over the three day battle.

Gettysburg is about 1.5 hours by car north of College Park. Along the way, I listened to Car Talk, one of the best shows aired by NPR. It’s a tremendous show. If you’ve never listened to it, give a chance and you’ll be pleasantly surprised. I reached Gettysburg around 11:30am, and picked up a map of the battlefield at the visitor’s center. It turns out there is this 18-stop auto tour of the battlefield that pretty much everyone, I noticed later, decided to do. The battlefield is about 2 or 3 miles tall (if you want to include the first day’s skirmishes northwest of the town) and 1.5 miles wide. The Visitor Center is located along the Union Line, north of where General Meade’s headquarters are.

Since the Union and Confederate troops didn’t have cars back in 1863, I decided to walk the battlefield. I was the only one to have made this decision, though I did see some others biking around. I started walking south along the Union line, seeing the place where Pickett’s Charge took place and the ‘High Water Mark of the Confederacy’, the farthest point their soldiers reached against the Union line. Gettysburg has markers every 30 or 50 yards, marking X brigade of Y regiment of Z state and what they did at that spot. Looking out from Cemetary Ridge across the field to Seminary Ridge, where the Confederate line was, was pretty illuminating. The Confederate soldiers had to march across a completely open field for almost a mile before then having to charge an elevated position against the Union line. Crazy.

I continued walking south down the Union line, by Plum Run and the Peach Orchard, the Wheatfield, and made my way down to Devil’s Den. Devil’s Den is this bizarre rock formation in this Pennsylvanian farmland. The Union held it until it was overrun by Confederate troops, who then used it to shoot at the Union position on top Little Round Top.

As I was making my way towards Devil’s Den, I saw for the first time Little Round Top. This area of Gettysburg, indeed behind the whole Union line, is quite forested. Little Round Top has a special significance for me anyway, because that is where the 20th Maine Regiment under the tremendous leadership of Joshua Chamberlain held their ground and the entire Union line against superior Confederate numbers. I wasn’t sure exactly where the stand occurred, but as I approached Little Round Top from the southeast, I saw through the streets a low rock wall. I remembered a scene from the movie Gettysburg so I approached it. Sure enough, I spotted a lonely stone marker with the words ‘20th Maine’ chiseled into it. I had finally reached it.

At the battle of Gettysburg, Little Round Top was not occupied by either side. As the lines of each army began to extend farther south, this was a very strategic point. From Little Round Top one can survey almost the entire battlefield. Although it does not seem very high from the ground, the view from on top makes its stragetic qualities immediately clear. Colonel Vincent rushed to occupy Little Round Top for the Union and minutes later the Confederates were attacking it. Fearing they might sweep to the east and flank the entire Union line to the rear, he assigned the 20th Maine to hold the left most edge of the entire Union line. They had to “hold this line at all hazards.” They could not retreat or surrender. Chamberlain quickly assumed position a short distance down from the top of Little Round Top with a position with a short rocky wall. They repulsed numerous waves of attackers. The Confederates kept moving eastwards, trying to get around the line. Chamberlain would take every third man on his line and keep extending the line at angles. Finally, with ammunition almost run out and no other options left, he gave out the call: “Fix Bayonets!” Moments later, the 20th Maine charged down the hill with their bayonets, catching the Confederate soldiers by surprise and pulling out victory from the jaws of defeat. An incredible story. The Killer Angels, by Michael Shaara, is an outstanding read and highly recommended.

After leaving Gettysburg at around 3pm, I picked up some food at the grocery store outside Taneytown and headed back home. Cunningham State falls is on the way and I stopped by there to see the park, but Maryland charges people to gain entrance into state parks, so I said ‘no thanks’. I did stop by a brook running near the road for some quiet time in nature.

It was a nice road trip to see a place rooted in American history. I do find it amusing that I was the only Asian I saw there, and only three African Americans were to be seen. Heh. For more pictures, check out my gallery.

This weekend was quite slow going. A chronic headache and general soreness did not put me in the mood for much anything. Ross and I watched the third place match for the World Cup on Saturday, and I was happy to see Germany win. I tried working a bit more on some MATLAB computations for work, but didn’t get much anywhere. That evening I made veggie chili which turned out quite nice, and we watched two episodes of From the Earth to the Moon via Ross’s laptop.

On Sunday, despite my alarm going off early, Ross and I caught the Wimbledon final with the fourth (and final) set in progress. Federer was just too good. That afternoon we sat down to watch the World Cup final. I was going for France, but I stopped my support after Zinedene Zidane committed an incomprehensible personal foul by violently headbutting an Italian player. It was shameful, particularly for someone with such a storied career as his. It was also disappointing seeing the game go to penalty kicks. I don’t like team Italia, but oh well.

John leaves us on Wednesday to go to his conference in Albuquerque, NM so we have to get settled in for a week without his guidance. Todd should be around so it shouldn’t be too bad.

Happy belated 4th of July! No updates in a long time, but it’s been a busy last few days. My family came up here on Saturday, and we spent the afternoon and evening touring the University of Maryland campus and taking a trip to Ikea. My family thought Ikea was pretty cool, though I think Sapana was a little underwhelmed. Perhaps we had hyped it too much. We had some big plans there — we talked about ‘ikeaifying’ our formal living room (desk, reading chair, side table, lamp, bookshelf, everything) and also to replace Sachi’s very old bedroom furniture. Ultimately though, we had no way of bringing large items back home and Cary, NC is too far away for any of the IKEA stores to ship to us. So my family just picked up a few small things.

Sunday was spent in Washington, D.C. We visited the National Gallery of Art, Smithsonian Air & Space museum, and walking around the Capitol building. We got back early to College Park and my mom found a great Thai restaurant nearby.

On Monday we drove out towards Annapolis, the capital of Maryland and home of the US Naval Academy. Annapolis was a surprise to me; it is a nice small town with a great harbor area and small shops. We took a boat tour out on the harbor and saw the sprawling Bay Bridge in the distance.

After picking up sandwich wraps, we drove over to a small park just before the Bay Bridge (costs $5 per person!) and walked along the beach for a while. We continued our tour of the Chesapeake area and the Eastern Shore of Maryland across the bridge and then south towards the small bayside town of St. Michael. And is it ever small! Just one real street; one could walk the entire town in maybe 10 minutes. It was almost closing time for the maritime museum, so we skipped it. We only spent maybe an hour here before heading back home, though we stopped in Baltimore and had dinner at the inner harbor area (which was underwhelming due to poor service).

The 4th of July was spent in our nation’s capital. We hit the National Zoo and saw its star attraction: Tai Shen, the baby panda cub, who turns 1 year old this Sunday. He was adorable and put on a wonderful show for us. He started on a branch, then climbed down and sat by a log while hunting for food, then clamored up onto a rocky outcropping before we left.

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I asked the kind volunteer there, and it turns out he sleeps half the day and eats the other half! Everything he does is adored by the hundreds of people who watch him. What a life! Afterward we caught lunch at Dupont Circle (where I stayed in my D.C. trip two Octobers ago) and continued down towards the National Mall. I took them to the recently finished World War II memorial.