Sunday, March 31, 2013

An entry on things that have been on my mind lately


Hello World,

 I've been putting a lot of projects on hold lately. The LED's have zero omega (translation, not spinning). That pump (which, I do have photos of*) for the liquid dispenser has mass flux zero. Though, I did learn that some people like to solder capacitors onto the shell of DC motors. Not sure how the math works on that, but it might have something to do with damping out the voltage spikes that come from a V-i graph of an inductor (direct current motors are essentially inductors spinning a magnet), and there's always that spark that occurs when you simply attach a hot wire to it. This means something physically.. A spike, spark.. spike-spark. Mathematically, it means asymptotes on a voltage-current graph. I'm not really good with electronics, so my best bet is to refer to wiki for any reasonable answers.

According to wiki,

[http://en.wikipedia.org/wiki/Inductor]

Nothing.. Except that "inductive loads" are weird, and follow a v = L*(d/dt)*q relation. So if you suddenly apply a current via turning on a switch leading to an inductor, the difference between the on and off state in the current occurs nearly instantaneously, therefore it's like dividing by 0, and thus the voltage theoretically approaches infinity.

[edit: Stephen brought this to my attention. http://youtu.be/BRRolKTlF6Q ,
 remark : okay, fine. point made. [-_0]

Though, according to other articles, diodes are popularly used. I'm not sure why these guys decided to use capacitors in this way. The cap. in the middle is essentially an element parallel to the inductor load, but I really don't see the logic behind the ones attached to the motor shell.  I should probably save up to buy an oscilloscope at some point in my life, just to see what's happening with these devices..

For this blog entry, I'm just going to post a bunch of old photos from months before and give description to them WOW.- for the shake of sharing. Hope you find some of them insightful.

As mentioned above, I was having a look at the pump from a liquid soap dispenser I blogged about once. The problem with that was that the circuit board controlling it suffered from some chemical damage during the product's short lifespan. At one point, I attempted to replicate its functions with another board, but the project was placed on hold (seriously don't remember why..).




The DC motor in question. 3 capacitors, 1 connecting each lead to one another, and 2 other caps. connecting each individual lead onto the metallic body of the motor. Mysterious..

This guy [http://www.youtube.com/watch?v=TjlN-TitYsw] talks about using a capacitor to help start a motor. Calls it a "Start Capacitor". Similar to this maybe?






The pump for the liquid soap dispenser, looks like it could have been 3D printed, but upon closer inspection the individual parts seem to have been molded. It's really just tiny rotors being moved by a gear which is spun by the shaft from the motor. @_@. Simple..



link related*
[http://www.youtube.com/watch?v=seZqq1qxW30]

The whole disassembled set-up is pictured above. Battery powers motor, which spins rubber band thingy, which is coupled to the pump. Pump, has spinning rotor which displaces liquid within. This is how a liquid soap dispenser works.

Here's something entirely different that I came across. On of the college campuses in Las Vegas, going down the stairs adjacent to one of the science buildings, there's this AC set-up. I took a few photos of, not sure what to call them, "metal slabs" running vertically up and down the set-up. They're bolted.. As wind travels through the area, these bolted slabs vibrate, and you can hear them throttle back and forth.



 Didn't figure out what they were installed for. They were slack, meaning there was was no tension on them. I'm just going to take a guess and say they're here for decorative purposes - like the capacitors on that previous motor :p






 Between then and now, not much happened. My friend Geoff, and I did attend CES. We probably took too many photos, and at one point went on a scavenger hunt to get as many "World's "something" TV" marketing phrases in photo. Maybe, I'll dedicate a future blog post to that.


The IEEE people were there. After talking to an retired engineer who gladly handed us some IEEE paraphernalia (USB drive, notebook, business card, etc) we got the chance to lay eyes on this machine. This wasn't exactly the newest technology [http://www.diginfo.tv/v/11-0070-r-en.php] of the year, but it was still pretty amazing. It's a fog dispenser slash holograph making thing. According to the article, and videos on the technology found around the net, the fog acts like a reflector which transmits multiple images at various angles. Theortically, if you had more hologram projectors around this thing, you could see a full 360 view of the object as your move around it.


We also got to see a dance routine of quadrotors. From the video below, notice how the one on the right is a little jerky (dancing*), and then does a full rotation in mid-air. Well, they're all in "mid-air".





Here is a power transformer? A something.. To myself, it was a gigantic wall outlet. Just look at the size of those plugs. Definitely something worth taking a photo of. This metal box, occupied one of the columns at the conference. People walked by, not realizing how much of a super-star it really was.


 And of course, hexapods:
It's like you can't go anywhere without seeing one of these guys. These came from a toy company which created a game out of them. They shot little plastic darts and disks at each other. Parts of their "armor" attached to their legs would spring off when the area was hit by one of the darts/disks.


 CES wasn't the only tech related event my friends and I visited. For the first since ever, Las Vegas hosted it's own Maker Faire! We went to have a look-see on what other people were doing.

There's a whole group dedicated to making R2-D2, some local companies attended, and a group exhibiting a laser cutter. There was also the arts and craft section, but they weren't as amazing as the electronic section (which included the R2-D2s and a freaking laser cutter). A comparison, we spent more time in the latter section.




Humm, maybe I did lie earlier.. There were no hexapods at this Maker Faire. I'm not recalling, and none of the photos I took include any. This needs to change.

 More recently, whilst along a journey of a daily jog, I stumbled upon something. It looks like someone had taken an old (OLD) car, disconnected the front panel, and then halved it with a welding torch along the middle. I was somewhat tempted to bring parts of this back home, but convinced myself that my dumpster diving days are long over. Not that I wouldn't, it's just that this thing was very heavy.

On the left you see a thermometer, and an amp-meter I believe? The reading on the thermometer starts at 200F. It seems unusual - whatever. The photos on the bottom show a lever-based controlled system for a car's fan unit. The opposite side of the lever case has a display panel for heat, air flow, and an on/off switch (the 3 levers), and the 2nd photo here shows how that "signal" was sent. It uses pulled wires, similar to the set-up with a bicycle brake you might be familiar with. Just looking through this vehicle was like looking back at our history from 50? years ago. I don't think we use this kind of technology anymore, except in bicycle brakes I guess. Everything has a LCD display with a capacitance digitizer, not an actual "analog" display with actual "wires" and actual mechanical forces involved. 




These next three photos are actually more fascinating. They include the brake and throttle pedal from the car. The video above shows how the system reacts when these get pressed down. I couldn't help but think, "omg, this is a prismatic connection" when I was dealing with the brake pedal.





I guess that's it for now.

Currently, I'm getting ready to head back to school now that Spring Break is finally over. Most of last week was spent doodling around with code, playing Heart of the Swarm (woot!), and learning how to solve inverse kinematic (IK) problems. I'm still not comfortable with the latter, but I'm hoping to write a proper blog post on the topic once I get a handle on it. Honestly, I thought it would be as easy as, "find the inverse of cosine," but it turns out it's more like, "find the transformation of the transformation of.." I managed to get my hand on some Springer books a few days ago, so.. Still researching. Oh, and those spinning LEDs.. that's also on hold until I can design a way to keep an LED powered as it moves. And the crayfish, thats been on hold since forever. DanceBot, SpinLED, and Project Cray. My 3 unfinished projects >_<!


The only real thing (aside from scripting) that I've accomplished so far was placed a glove on two moving sticks, and attached a dry-erase marker to draw with on a whiteboard. I got the inspiration from an instructables a lovely friend sent to me:

 [http://www.instructables.com/id/Robotic-Arm-with-Servo-Motors/]

You'll notice that dustynrobots also included a PID_v1h library in her script. That stands for proportional-integral-derivative controller. It's basically a set of feedback algorithms that correct for position. So, since I don't like using code based on math I don't understand, I'll have to learn this as well. It seems pretty intimidating, but at least that library is well documented.

It's nearly 7 now (am). I should probably get some sleep.

Night World,



No comments:

Post a Comment

(-_-)...