Monday, January 21, 2008

Misc. pics, lab things, notes, etc.

So, I received word that it is not necessarily a good idea to broadcast on the web the unique specifics of a design project of your own. Especially when you're design is a month away from having a shootout with two other designs. Not like the other guys couldn't figure these things out. They are a lot smarter than me. (One design is from Los Alamos, and another from a precision measurement microphone company in Denmark. *gulp.*) But I edited the last post, and I am sorry to say I can't post any pictures of the [really sweet] upgrades I've done to my own pistonphone. Oh well. But I did get my hands on a "lab approved" camera, and took a few snap shots of things around/on my bench. Following that are my attempts at making nigiri (the Japanese equivalent of a peanut-butter sandwich), and some other misc. fotoes. Enjoy.

The circuit. Doesn't hurt to show this I suppose. It looks simple, but that's because it's been vector-boarded, and a lot of connections are underneath. On the bread-board it was a mess of wires.

Spent several hours Saturday making this little joint. The inner-axle is a piece of welding rod, and there's a Teflon sleeve that covers it, so it turns really smooth, and is tight lengthwise. I probably could have ordered a piece, but I didn't want to wait until Tuesday to get it.

Using some sensors that had a gigantic DC offset, so I grabbed this spare amplifier and modded it (with the pots on the outside) to sum a variable offset with the signal and hopefully cancel out the offset of the sensor. Works ok, but it adds a lot of noise (garbage signals) to the data. Can't use the sensors without it though... possibly something to improve in the future.
The low-frequency microphone as it currently stands. The pistonphone project trumped this one in priority, so it's on hold, but I just got some 100G resistors from Digikey so I can start designing the amp.

Ferrite. Spent half of my day trying to figure out how to machine the stuff. It is really hard brittle.

Leftovers on the bench. There's a microphone trapped in the brass, waiting to be released.

Ok, enough lab stuff.
Now hanging in my room.

My bag of really nice sticky rice. Says "Akita otome" but I don't know what that means. It's Japanese at any rate. And, most importantly, it tastes goooooood

5 dollars for 5 sheets at the grocery store or... 5 dollars for 40 sheets at the asian market. Take your pick...

My rad new implement of culinary destruction. Courtesy of a beloved mother.

Onigiri. Get your hands wet, and rub some salt on them. Grab a wad of rice, and press it into a triangle with your thumb and forefinger. Press out a hole in the middle and put your filling of choice in (these have tuna inside). Place on half sheet of nori, and fold around the triangle. Presto - you have the lunch of millions of Japanese college and highschool students. If you want to go hard-core, find a bottle of something called "umeboshi", and put one in the middle.

For kicks, or mostly because I wanted to see how the capsule was constructed, I took apart my home recording condenser microphone yesterday.

This is weird, and I haven't figured why they did this. Normally the backplate is at high voltage, and the diaphragm is at ground potential. In this case, it's reversed - the diaphragm is at high voltage. And, there is a contact in the middle, to charge the diaphragm, and - this is what's weird - it also suppresses the 0,1 mode of the diaphragm. I can't for the life of me figure out why you would want to do this. This essentially will give it a higher natural resonance frequency, but should also decrease the sensitivity. Maybe it is difficult to reach 20k with a 1-inch diaphragm without doing this, I dunno.

Lastly, and crazily, recently I've been having inspiration to draw again. But, I haven't had a lot of time for it, and the skills have rusted. but I jotted this down last night. I think it was a subconscious response to Uncle Ted's request that I come up with an avatar. Maybe I'll color it and make it into an avatar. Or maybe I'll make myself a cool pair of brass and leather shop goggles first

Tuesday, January 15, 2008

Unbelievable... (notes)

So, I'm making a home-brew [something. edited.] I had to figure out how to de-modulate the signal, so I looked up this precision-rectifier circuit online, and decided to wire it together. It was a really large circuit, and the irritating thing about circuits is, even if they are incredibly simple, you can spend hours debugging the circuit to make sure the connections are all correct. But the crazy thing is??

bum ba da dum ba daaaa!
It worked first time!

Well, almost - the rectifier part worked but I had to convert an inverting amplifier to a non-inverting amplifier farther down the signal chain. But that's peanuts, and the rectifier (the hard part) worked. Seriously, this has got to be a first, in my entire history. Anyway, I thought I'd share in my happiness, like the lady in the Bible who threw a party because she found her lost coin.

Secondly, I tried being ultra responsible and going to bed by 10:00 last night. Like normal, whenever I try something like this, I wake up around 2:00 AM, and can't get to sleep until about 5:30 AM again. In this interim, I did the following:

1. Tried to sleep for 2 of those 3.5 hours
2. Had several bowls of cereal.
3. Found my old Chinese textbook and reviewed all 400 characters.
4. Fixed my ultra-sweet new Ipod so that it plays youtube music video's in a play list.
5. Thought up a rad design for a microphone, and several ways of improving the LVDT mount

Then I fell asleep again somehow. Lesson: stay up until 12:00 AM if you want to get good sleep. Just kidding. I guess. Maybe I'll try it again for a few more days.

Friday, January 11, 2008

The Boothmans, SOMA, and a couple movies

I got back to State College yesterday and the last few days before I returned I was able to hang out with two of the most interesting people I've ever met. My parents rent out a couple rooms, and currently living there (though, soon to leave) are Hilary and Jane Boothman. The Boothmans have been friends of our family since I was a little kid, but they moved to Yakima, so before last week the last real memory I had of them was playing around with their fat little goat Spiff (I dare you to think up a cooler name for a goat), and catching snakes and mantids in the tall grass around their house. I guess that doesn't narrow down the time window that much, but they tell me it was when I was twelve or so.

They are both WSU students now, and so have come back to Pullman. They both have the really strong spiritual spine that runs in their family. One of the coolest things about having them renting from my parents is that it seems like every spare second of the day they have, they spend singing/harmonizing/playing music with each other. God seemed fit to bestow on them not only talent with musical instruments, but gorgeous voices as well. Hilary sings, plays piano, violin, guitar, and pennywhistle among other things, while Jane has an incredible voice and plays piano. So whenever both of them have a free moment, really great music fills the living room, and it is something that my parents are going to miss when they leave.

I was bold enough to capture their rendition of "How deep the Father's love for us" on camera. It's recorded by a little digicam and it's in mono so the recording doesn't do them any amount of justice, but enjoy it anyway:

They invited me to SOMA, a college ministry put on by my church, Tuesday night. I was very impressed by the group. For one, they were very mature, for what I was used to college ministries being. Undergrads, grad students and young professionals seem to meet together and integrate very well. The teaching was mature, and not lacking in scripture, or the enjoyment and preaching thereof. The music was simple and attractive. I captured the outro. This is the music leader of EFree, Daniel, playing with Hilary. Daniel is a cool guy, he's taken responsibility in the church and helped out with leadership. Apparently he applied for seminary in Biola and may be leaving soon, but it seems like if he wants to be a pastor he is doing exactly the right thing at SOMA, learning how to preach and teach. A solid singer and musician as well.

Met quite a few other people there, like Mike, the guy who painted my parent's house over summer, and Josh, a civil engineering student who seemed to notice that I am probably the worst guy in the world at socializing after churchy events and came over to find out who I was. Then, lastly, caught up with Karl Olsen, who has been one of the leaders of the college group at EFree for a long time, and will finish up his PhD in (Lord willing) about a year and a half.

Anyway, getting to hang out with Hilary, Jane, and these people was some of the most fun I had over break.

Monday, January 07, 2008

Kurisumasu (Christmas) 2007

Well, it's a little late, but I thought I'd post some Christmas break pics. I could do my usual thing and describe the happenings of each picture but I got like... 70 pics, and I think you get the general idea from just looking at them. They are in chronological order here, so, enjoy!