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
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
posted by tmm at
9:05 PM
4 Comments:
Timu-san,
I very much like the start of your avatar. This might fit you very well indeed.
As Always,
Your affectionate Uncle
Hi Tim :) the picture is cool indeed. Do you have any suggestions on what to stick inside those triangle things if you don't happen to like tuna?
I vote that we can put Grandpa's dog into one of the triangle things. Man, that thing drives me crazy, and that's just hearing it over the phone.
I wonder what Pippin would taste like.
This comment has been removed by the author.
Post a Comment
Subscribe to Post Comments [Atom]
<< Home