Tuesday, August 25, 2009

Mjöllnir I: play time

A few shots of the coil taken with the shutter open for 15 seconds (PowerShot A650 IS)

Solar Flare

Tea anyone?

ARC de Triomphe

Monday, August 24, 2009

Adventures in Healdsburg

When we first arrived at the Davis airport, Breanna and I met the instructor who had rented the plane before us. He handed me a paper clip with the keys to the airplane and said, "you might try using this to keep the window shut." Evidently, the window latch had fallen off during taxi and was somewhere in the run-up area. After many unsuccessful attempts to keep the window shut, we took off in our more breezy Cessna 152. We were headed to Healdsburg, a little town north of Santa Rosa, to celebrate Kirstin going to vet school.

Our 40 min. flight took us west over Lake Berryessa, past the vineyards of Napa Valley, and by the highest landmark in the area, Mt. St. Helena. I couldn't help but think of how much time we were saving by cutting the 2 hour drive to less than half the time and how we were able to enjoy a beautiful view of the valleys below.
Above the vineyards and country roads of Healdsburg

More wine country through the window that wouldn't shut (Healdsburg airport can be seen in the distance)

We landed at the Healdsburg airport where Kirstin was waiting to pick us up. We drove to her house and soon after we arrived, toured parts of her family's 80+ acres. Later, we celebrated with her friends, family, and coworkers over barbecued burgers, salsa made fresh from the garden, and cake. Everyone enjoyed the food and company. As the evening progressed, I noticed a layer of clouds slowly approaching from the south. Though I was warned by a few at the party about the fog, I was confident that the weather reports would be accurate and the cloud layer wouldn't reach us till after we left. But as the outside temperature continued to sink, so did my faith in the reports. The drop in temperature hastened the formation of clouds up the valley. Checking the recently updated online weather reports only confirmed what I already suspected, we weren't going to be flying anywhere that night.

I felt bad for not getting Breanna back to Davis when she expected and for imposing myself on my hosts, but at that point there wasn't much I could do. It seemed that flying had increased our transportation time rather than shortening it. However, we were warmly welcomed to stay the night and after Breanna and I made a few phone calls letting people know we would be late in returning to Davis, our adventure continued.

Kirstin, her mom Kathy, Breanna and I then drove to Ed and Jean's house (close friends of Kirstin's) where we stayed up talking into the early hours of the morning. Breanna and I spent the night there and woke to a generous breakfast of omelets made with fresh vegetables from Ed and Jean's garden. Kirstin stopped by in the morning to join us for breakfast before heading off to a short day at work.

Still waiting for the cloud cover to burn off, Breanna, Kathy, and I decided it would be fun to go riding. Just as we were about to leave, Kirstin arrived back from work and we all went to her place together. Having nearly no riding experience, I had to be shown everything. Luckily, I was surrounded by real experts and before long was able to walk and trot around the arena. Now it was time to put my very elementary knowledge of riding to use. Kirstin led Breanna and I on a short ride up Pony Hill. From the top, we had a great view of the valley below, but above us, the clear sky beckoned our return to Davis.

Walking around the arena, being taught by the experts

The view from atop Pony Hill

Life rarely goes according to plan. But sometimes, significant changes can create an adventure better than what we planned for.

Thursday, August 20, 2009

Mjöllnir I: It's alive!

It's working!!! Mjollnir I came online today. Here are some photos of its first successful runs. Without any optimization of the primary coil, I have achieved spark lengths of 20 inches.
In the daylight it is difficult to see the longer arcs because they are so thin. In the picture below, I attempted to adjust the exposure and fstop on my camera to make the sparks more visible, but I'll probably be able to take better pictures at night.
Below is a video of the coil in action!

Sunday, August 16, 2009

Why you might see my brother climbing trees

The following is an anecdote written by my brother Ryan, seen below with his Triton Cockatoo, Cupid.
Well, I decided to go with the real short crew/buzz cut for the balance of the summer. So I did. When I got to school, the scarlet macaw I had to feed basically thought I was a completely different person and hissed and tried to bite at me through the cage. I was also not wearing my normal EATM uniform because it was a work day.

Then, when I got home, I approached Cupid's cage just like I usually do to say 'hello'. Her crest went up and she headed to the back of the cage. I thought she was just being a bit nervous, but she was actually totally spooked out. So, when I opened the cage door, she hit the floor in no time flat and flapped out onto the ground. I didn't want to scare her more, so I didn't grab her, but then she flat took off--from the ground! She went up over the backyard fence and out of sight. I headed out to go look for her and couldn't find her anywhere. I figured she couldn't have gone far because she barely made it over the fence and swooped low once she did and I hadn't seen her fly up anywhere so I was totally baffled. And, naturally, since she probably could see me from wherever she was hiding, she didn't call out like she usually does because she didn't want me to know where she was! So, I headed back inside and took a nap.

I awoke to a knock at the front door from my neighbor across the street. She had seen Cupid and wanted to let me know. So I went out with her and she showed me the shrub she was sitting on. So, I walked back inside to get some cashews. When I came around the corner again and looked at Cupid again (from like 50 yards) she could tell I was after her and flew up into a tall pine tree across the street. I went over and located her with the neighbor and her husband, children and children's friends and then proceeded to ponder the situation. I realized that she was spooked by my appearance and, because that was aversive to her, she would not fancy my chasing her up a tree unless she knew I had friendly intentions. So, I went back to my house with the kids stationed on the grass at the base of the tree to keep an eye on her (four 7 & 8 year old girls). I changed into my regular EATM uniform (which is normally what she sees me in when I come home) and found a hat to put on. I came back out with my ladder and bamboo retrieval pole and then proceeded to call her name, whistle my tune to her and get her attention. She signaled that she knew it was me then by doing her head bob and making happy noises.

So, I told the kids to keep an eye on her in case she spooked again and set the ladder up to get to the first branch of the pine tree. I had to do a bit of scouting out of this particular tree beforehand. Kind of hard to describe. If you saw it you would understand. Anyway, this whole time the kids are calling Cupid's name and saying, "Wow, this is just like Animal Rescue on Animal Planet" and asking me why I cut my hair, that I should wear a wig and how I was going to climb down. So, I did my best to answer their questions as I scaled the tree--bamboo pole in hand. I had to reach way way out, but Cupid did recognize me and walked on to the pole without much coaxing and got to my hand. I tossed the pole down to the kids (much to their delight) and then proceeded to climb down the tree--one handed.

After making it back on the ground, I was met with cheers from the kids and sat down on the grass with them to show them Cupid up close and answer another bunch of questions and listen to their stories. Meanwhile, two friends from the zoo drove by and stopped in the middle of the road to see what I was up to, so I walked over with Cupid and the kids to say 'hi'. While in the middle of the street, another car coming the other way had a recent EATM graduate who also stopped to see what was up and her boyfriend hopped in the shotgun seat right afterwards (she was coming to pick him up). After that I excused myself saying that Cupid should probably go home now since she had had quite an adventure.

Something similar to this happens at least once a week. I am convinced that before I move out I will have climbed every tree within a quarter mile of Cupid's cage. No joke.

Here I am with my brother's bird

Tuesday, August 11, 2009

Mjöllnir I: first run and the aftermath

I was hoping that upon completion, I'd simply plug in the coil and everything would work perfectly. That didn't happen. I'm writing this entry from the CAE lab on campus because the coil damaged a few things, my internet being one of them. Below is a picture of the assembled coil.
After tuning the safety gaps and main spark gap I placed the assembled secondary and toroid above the primary coil and connected them to a good earth ground. The first time I turned on the coil, arcs were generated from the secondary to the inside tapping point on the primary coil. I pushed the tapping point flat and ran the coil again. This time arcing occurred to the secondary ground wire. Again, I pushed that closer to the secondary to avoid the arcing problem. During the first two runs I also noticed "racing arcs" along the secondary coil. This is caused by over coupling between the primary and secondary coils. I will need to raise the secondary a bit higher to prevent this from occurring. The third time I turned on the coil, there was no arcing to the primary, but moments later I heard a loud popping sound over the spark gap and a shower of sparks and smoke shot out of the line filter. I immediately turned off the coil, but as I would later find out, the damage had been done. Below is the line filter with a hole burned into the casing just above the green ground wire.
Having run the coil twice before (and just the primary a number of times) I'm baffled as to why this occurred. With the line filter gone, I didn't want to run the coil again for fear that the house electronics would be at risk(the line filter prevents voltage spikes from traveling back into the house wiring). I then went inside to do more internet research only to find that... I didn't have internet. The router no longer shows any signs of life. I'm hoping that only the 12vdc transformer that powers the router is broken but I have yet to find out. I tried plugging an Ethernet cable directly into the cable modem, but unfortunately that hasn't worked for me either. For now it seems I'll have limited internet access and a good amount of troubleshooting to do.

Saturday, August 8, 2009

Mjöllnir I: secondary construction and strange phenomena

The slow, tedious construction of the secondary coil has begun. I have to make approximately 1200 turns with a quarter mile of wire. Below is a picture of me taken just after I started. I've been listening to TED talks as I work, getting up to stretch every 20min. and to start the next talk.
Now, on to the strange phenomena. Whenever I activate the primary coil, my smoke detector (on the wall roughly 12 or so feet from the coil) goes off. With no smoke being generated, it seems strange that the alarm would be tripped. Also, the alarm shuts off immediately after I turn off the coil. I have reasoned that the alarm must be detecting something generated from the coil during operation. When activated the coil produces light and sound from the spark gap, and electromagnetic waves from the coil. Without having tested anything yet, my guess is that the EM waves produced from the coil are causing the sensitive electronics in the fire alarm to detect a small current. See here for how this part of a smoke detector operates.

UPDATE: after 15 hours of coiling, I have finished the secondary coil and am beginning to coat it in polyurethane!

Wednesday, August 5, 2009

Mjöllnir I: time for ear protection

Mjollnir I is closer to completion with the secondary coil being the only major component yet to be made. I've recently completed the safety gaps on both the Terry filter and capacitor bank, and have finished making the primary spark gap. In the picture below, you can see each of these parts connected and ready for operation with the magnet wire for the secondary coil in the foreground. Upon completion of the coil, the safety gaps and main spark gap will need to be adjusted for optimal performance. Besides the secondary coil, I still need to construct a strike rail to protect the primary coil, a switch box for ease of operation (right now I'm still plugging and unplugging the coil to operate it), and purchase a fan to quench/cool the spark gap.

The primary spark gap I chose was a multi-gap design based on the Richard Quick multigap. Rather than having two electrodes (making one big spark), I have ten electrodes, which forces the arc to be distributed across nine separate gaps. This improves electrode cooling by distributing the heat over more electrodes, and makes smaller arcs, which can be easily quenched. When the gap arcs, plasma is formed between each electrode, making a highly conductive path for electricity to follow. This creates a connection across the electrodes for longer than is needed to discharge the capacitors. By quenching the gap, the plasma is removed, suppressing the arcs and improving the coil's efficiency. Below you can see the main spark gap in operation (taken without a flash).
In the close up below, the plasma between the copper tube electrodes is clearly visible. When the coil is operating, it is EXTREMELY loud. So loud in fact, that I need ear protection if I'm going to be operating the coil for any length of time. Unfortunately, this means that I run the risk of waking up my roommates or neighbors if I want to work on it at night(which is when I seem to make the most progress). Now for the secondary coil!

Sunday, August 2, 2009

Who's reading my blog anyway?

That's what I was wondering this afternoon. So I took a look at the statcounter I have set up on my blog page and this is what I found. While the majority of hits are from the states (over 90%), I've got viewers in every continent but Antarctica. Somehow I don't think these are regular readers, but it's an ego boost nonetheless.