DC Motors

Recently I was working in a Solar Car design .

I had a problem in the designing of this solar car As my study is mechanical Engineering .

The problem was that the solar cells produce ( Direct current ) while all the motors i deal with work with ( Alternating current ) .This is related to ( Electrical Engineering Field )

After long day of search  I found this file talking about motors work with Direct Current ( DC Motors ) 

I hope that i can help somebody faced the same problem . ^_^

HERE YOU ARE THE LINK AGAIN http://www.4shared.com/get/c7Q1RV20/Lecture_09_DC_Motor.html

future with robots

Till now designers are unable to make a robot that can simulate the smooth movement of human ,but robot also has some features .Robot can work long time without rest or mistakes, can carry heavy things and can work in narrow space such as in nanotechnology. Now we are going to discuss the latest Developments of robots in some important fields in our everyday life .

Using Robots to Build Beautiful Structures

We will let the photos talk about how we can use robots to build fantastic structures :

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Home-robots :

t's been a long time coming, but Intuitive Automata's Autom robotic weight loss coach is now up for pre-order on a dedicated "MyAutom" website. If you haven't been following the saga of Autom, it was first an MIT Media Lab robot with a significantly different look. Autom's developer at MIT, Cory Kidd, co-founded Intuitive Automata to help commercialize Autom based on the original MIT project, and it's starting to look like everything will be coming together within the next year. Not to get off topic or anything, but it's fantastic to see a research robot like this make the difficult jump into the consumer market. Congrats to Dr. Kidd!

Anyhow, back to the robot. We know that Autom is designed to be exceptionally interactive, crunching data on your health, diet, and exercise regimen and giving back friendly and constructive criticism. Studies have shown that people who use Autom stick with their diet and exercise routines for twice as long as people using more traditional weight loss methods. Don't ask me how, maybe it's something about those big blue eyes?

If this sounds good to you, you can be one of the very first people to have this friendly little robot helping you out every day with a deposit of $195. This is not the final price, however, it's just the pre-order deposit. The final price is the $195 deposit plus a balance of $670 when the robot ships, for a total of $865. This does seem a bit steep, although I'll admit to not being familiar with how much a typical weight loss program costs.

military-robots:

Textron's T-Ram is the Suicidal Mini-UAV You've Always Wanted

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The U.S. Air Force has been looking for what they're calling a "Lethal Miniature Aerial Munition System" to be fielded with special ops units next year. If the name of the program doesn't explain it, the above pic should: they essentially want a mortar round with wings, a camera, and a little engine. In other words, a surveillance UAV that can suicidally attack targets on command.

There are several systems with this capability currently in the works, but the operational requirements and principles are all the same. LMAMS needs to weigh three kilos or less, including the vehicle and the launching system. It needs to be able to deploy and fire in under 30 seconds, reach an altitude of 100 meters, and acquire and track a human-sized target in a further 20 seconds. At that point, the drone can either dive at its target, landing within a one meter radius and exploding its small (but still quite lethal) warhead, or it can loiter for up to 30 minutes, sending back live video.

Now, this seems like a fairly dangerous little robot to have around, but before you get all worked up about killer robots and stuff, remember that these special ops units already have tools to deal with situations that the LMAMS is designed for: namely, blindly chucking dumb mortars and grenades at things, calling in air support, or putting themselves in harms way to get a better view of their target. All the LMAMS does is to reduce risk and collateral damage. Or at least, that's the idea, but whether it'll work in practice remains to be seen.

humanoids :

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Dr. James Law, a researcher at the Department of Computer Science at Aberystwyth University, has had an absolutely fantastic idea: he's nominated the iCub robot to carry the Olympic Torch as part of the 2012 Olympic Games, which will be held in London (that's in England, folks) starting next summer.

Dr. Law is proposing that iCub be included in the torch-carrying relay in honor of the 100th anniversary of the birth of Alan Turing, one of the guys who arguably invented the computer and whose test for artificial intelligence robots are continually striving to pass. This is a great idea, but I think that iCub should be part of the torch relay on its own merits: it'll be a first for robots and great publicity for engineering education and all that. Or at least, it'll be great as long as iCub doesn't faceplant in a puddle and snuff the torch out.

The only problem with this idea is that the short-sighted and obviously outdated nomination rules specify that all nominees have to be at least 12 years of age, which would mean that iCub wouldn't technically qualify. On the upside, nowhere does it say that nominess have to be human, so maybe iCub has a shot at this after all.

 

Smallest electric motor ever

dn20863-1_220For the first time, an electric motor has been made from a single molecule. At 1 nanometre long, that makes the organic compound the smallest electric motor ever.
Its creators plan to submit their design to Guinness World Records, but the teeny motor could also have practical applications, such as pushing fluid through narrow pipes in "lab-on-a-chip" devices.
Molecules have previously converted energy from light and chemical reactions into directed motion like rolling or flapping. Electricity has also set an oxygen molecule spinning randomly. But controlled, electrically-driven motion – necessary for a device to be classed as a motor – had not yet been observed in a single molecule.
To address this, E. Charles Sykes at Tufts University in Boston and colleagues turned to asymmetric butyl methyl sulphide, a sulphur atom with a chain of four carbons on one side and a lone carbon atom on the other. They anchored the molecule to a copper surface via the sulphur atom, producing a lopsided, horizontal "propeller" that is free to rotate about the vertical copper-sulphur bond

Record smashed

Above the molecule they placed a metal needle a few atoms wide at its tip. When they flowed a current from this tip, through the molecule, to the conductive copper below, the molecule converted the electrical energy into rotational energy. It bounced around in jittery hops about 50 times a second.

Because the propeller is asymmetrical, there are two ways it can be oriented with respect to the copper. In one orientation – but not the other – the molecule's hops were not random but slightly biased towards rotating clockwise, allowing the researchers to classify it as a motor.

It is not clear why the bias occurs but Sykes suspects that an inherent asymmetry in the tip of the metal needle could explain why it only occurs in one molecular orientation.

Friction fighter

If accepted by Guinness, the motor will be a record smasher. The current world-record holder for the smallest electric motor is a giant by comparison, composed of two 200-nanometre-long carbon nanotubes. Current running through these nanotubes pushes drops of molten metal from the outside of one tube to the other.

Sykes hopes to harness his tiny motor to fight the friction that slows fluid flow in nanosized tubes.

Kevin Kelly of Rice University in Houston, Texas, who was not involved in the work, points out that if electrical energy transfer behaves differently depending on the shape of the molecules, this could have implications for the design of molecule-scale electrical circuits, which could be used in tiny sensors or computer chips.

Journal reference: Nature Nanotechnology, DOI: