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Posts about electricity

Lenz’s Law in Action: Eddy Current Tubes

Posted on April 27, 2009 Comments (0)

Eddy Current Tubes — Drop the Magnets down the tube. An eddy current is set up in a conductor in response to a changing magnetic field. Lenz’s law predicts that the current moves in such a way as to create a magnetic field opposing the change; to do this in a conductor, electrons swirl in a plane perpendicular to the changing magnetic field.

Because the magnetic fields of the eddy currents oppose the magnetic field of the falling magnet; there is attraction between the two fields. Energy is converted into heat. This principle is used in damping the oscillation of the lever arm of mechanical balances.

Posted by curiouscat
Categories: Science, Students
Tags: electricity, experiment, physics, Science, science explained, science facts, webcasts

Using Virus to Build Batteries

Posted on April 5, 2009 Comments (1)

MIT researchers have shown they can genetically engineer viruses to build both the positively and negatively charged ends of a lithium-ion battery. We have posted about similar things previously, for example: Virus-Assembled Batteries – Using Viruses to Construct Electrodes and Biological Molecular Motors. New virus-built battery could power cars, electronic devices

Gerbrand Ceder of materials science and Associate Professor Michael Strano of chemical engineering, genetically engineered viruses that first coat themselves with iron phosphate, then grab hold of carbon nanotubes to create a network of highly conductive material.

Because the viruses recognize and bind specifically to certain materials (carbon nanotubes in this case), each iron phosphate nanowire can be electrically “wired” to conducting carbon nanotube networks. Electrons can travel along the carbon nanotube networks, percolating throughout the electrodes to the iron phosphate and transferring energy in a very short time. The viruses are a common bacteriophage, which infect bacteria but are harmless to humans.

The team found that incorporating carbon nanotubes increases the cathode’s conductivity without adding too much weight to the battery. In lab tests, batteries with the new cathode material could be charged and discharged at least 100 times without losing any capacitance. That is fewer charge cycles than currently available lithium-ion batteries, but “we expect them to be able to go much longer,” Belcher said.

This is another great example of university research attempting to find potentially valuable solutions to societies needs. See other posts on using virus for productive purposes.

Posted by curiouscat
Categories: Engineering, Products, Research, Science, Students
Tags: battery, chemical engineering, electricity, materials engineering, MIT, nanotubes, university research, using viruses, virus

Google Server Hardware Design

Posted on April 4, 2009 Comments (5)

Ben Jai, Google Server Platform Architect, discusses the Google server hardware design. Google has designed their own servers since the beginning and shared details this week on that design. As we have written previously Google has focused a great deal on improving power efficiency.

Google uncloaks once-secret server

Google’s big surprise: each server has its own 12-volt battery to supply power if there’s a problem with the main source of electricity. The company also revealed for the first time that since 2005, its data centers have been composed of standard shipping containers–each with 1,160 servers and a power consumption that can reach 250 kilowatts.
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Efficiency is another financial factor. Large UPSs can reach 92 to 95 percent efficiency, meaning that a large amount of power is squandered. The server-mounted batteries do better, Jai said: “We were able to measure our actual usage to greater than 99.9 percent efficiency.”

Posted by curiouscat
Categories: Engineering, Products, Students, Technology
Tags: cool, electical engineering, electricity, Engineering, Google, green, innovation, internet, Technology

Google Aids Green Action

Posted on February 11, 2009 Comments (5)

Google has a focus on energy as I have discussed previously. Google has been working to provide a way for people to get information on energy use in their homes that can be used to reduce your energy use.

Power to the people

studies show that access to home energy information results in savings between 5-15% on monthly electricity bills. It may not sound like much, but if half of America’s households cut their energy demand by 10 percent, it would be the equivalent of taking eight million cars off the road.
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We’ve been participating in the dialogue in Washington, DC and with public agencies in the U.S. and other parts of the world to advocate for investment in the building of a “smart grid,” to bring our 1950s-era electricity grid into the digital age. Specifically, to provide both consumers and utilities with real-time energy information, homes must be equipped with advanced energy meters called “smart meters.” There are currently about 40 million smart meters in use worldwide, with plans to add another 100 million in the next few years.
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Over the last several months, our engineers have developed a software tool called Google PowerMeter, which will show consumers their home energy information almost in real time, right on their computer. Google PowerMeter is not yet available to the public since we’re testing it out with Googlers first.

Posted by curiouscat
Categories: Energy, Products, Students, Technology
Tags: electricity, Energy, Google, green

Black and Decker Codeless Lawn Mower Review

Posted on November 5, 2008 Comments (3)

My old version of this mower just stopped working and the repair guy said it would cost $250 for a new starter, new battery… So I bought a new one: Black & Decker 19-Inch 24-Volt Cordless Electric Mulching Lawn Mower #CMM1200. He said that the new ones were not as well manufactured. I couldn’t imagine how you could make things worse (it is a simple product and just adopting improvement over the years should be really easy).

But, the starter on this model is horrible. You have to tun this incredibly cheap key in a very poorly designed socket. Fails over 80% of the time. The old model started easily essentially every time. The design was just as you would expect, foolproof. Whatever pointy haired boss approved this design needs to go into another line of work.

The ability of the mower to cope with high grass is very poor – much worse than the previous model. I had a good test at first given the time between my mower breaking and getting the new one. Not often an issue, but still not a good thing.

They had a poor indication of the charge left in the battery previously. They now provide no indication of the charge left. It makes you realize that a poor indication was much better than none.

Battery technology has improved a great deal, and that was one of biggest the weaknesses of the last one. Well they seem to have managed to provide worse battery performance after 5 years of improvement in that technology. Pretty sad.

The bag design is much better than the previous model. You have to assemble it yourself but it is much more sturdy and much better designed – you can replace the fabric and keep the frame. The old model the entire things needed to be replaced if the fabric broke. And given the flimsy design mine broke very early on.
Continue reading →

Posted by curiouscat
Categories: Engineering, Products
Tags: electricity, Engineering, green, Products

Wireless Power

Posted on August 25, 2008 Comments (3)

An end to spaghetti power cables by Maggie Shiels, BBC News

Mr Rattner envisaged a scenario where a laptop’s battery could be recharged when the machine gets within several feet of a transmit resonator which could be embedded in tables, work surfaces, picture frames and even behind walls.

Intel’s technology relies on an idea called magnetic induction. It is a principle similar to the way a trained singer can shatter a glass using their voice; the glass absorbs acoustic energy at its natural frequency. At the wall socket, power is put into magnetic fields at a transmitting resonator – basically an antenna. The receiving resonator is tuned to efficiently absorb energy from the magnetic field, whereas nearby objects do not.

Intel’s demonstration has built on work done originally by Marin Soljacic, a physicist at Massachusetts Institute of Technology (MIT). At the Intel Developer Forum in San Francisco, researcher Alanson Sample showed how to make a 60-watt light bulb glow from an energy source three feet away. This was achieved with relatively high efficiency, only losing a quarter of the energy it started with.

Don’t expect to see this available commercially this year, they estimate it is at least 5 years away. Though this is not university and business collaboration in the sense they are working together, it is in the sense that Intel is building upon the work MIT did. See other posts on university and business collaboration.

Posted by curiouscat
Categories: Energy, Engineering, Products, Science, Students, Technology
Tags: battery, electricity, Intel, MIT, Research, university business collaboration

Refrigeration Without Electricity

Posted on June 24, 2008 Comments (1)

Lack of electricity is a serious problem for vaccines and medicines that need to be cooled. It is hard to imagine that this is a problem, living in the USA, but this is still a problem today. As readers of this blog notice I really like appropriate technology solutions that provide real quality of life enhancements for hundreds of millions of people (which undoubtedly is influence by my father).

Posted by curiouscat
Categories: Engineering, Health Care, Products, Research, Science, Students
Tags: appropriate technology, electricity, scientists, TED, webcasts

Home Engineering: Windmill for Electricity

Posted on July 3, 2007 Comments (4)

photo of windmill

William Kamkwamba’s Malawi Windmill:

I built my first windmill when I was 15. Over the next few years I kept refining the design. I made many modifications to the plans i found in the book. For example, I increased the blades from three to four to provide more power output. The windmill now powers lights for 3 rooms and a light over our porch outside. I also use it to power my family’s two radios. I also can charge mobile phones that the neighbors have.
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Two weeks ago I used a computer for the first time. I learned about Google and searched for “windmill” and “solar energy.” I was amazed to learn how many entries there were for both subjects. My friends showed me how to create an email address and now I am on Gmail. Now I am practicing sending and receiving emails when I have access to a computer.
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On Sunday, my friends from National Solar and I completed the next phase of work on my electrical system. You can see a compete set of (my first) digital photos at my new site on Flickr. I had the following goals:

1. Upgrade the power generation in the windmill
2. Upgrade the battery technology and capacity, to provide more even power for more hours at a time
3. Increase the brightness of the lighting (lumens) to make it easier for my family to accomplish tasks at night, especially to read…

Photo: Back in November, the windmill was only 5 meters (15 feet) tall compared to 12 meters (36 feet) today. I raised the height because I discovered that the best wind was just over the top of the shorter windmill.

Posted by curiouscat
Categories: Economics, Energy, Engineering, Products, Students
Tags: Africa, appropriate technology, electricity, Energy, Engineering, engineers, green, home engineering, wind power

Electricity Savings

Posted on December 2, 2006 Comments (6)

Surprise: Not-so-glamorous conservation works best

When high school science teacher Ray Janke bought a home in Chicopee, Mass., he decided to see how much he could save on his electric bill.

He exchanged incandescent bulbs for compact fluorescents, put switches and surge protectors on his electronic equipment to reduce the “phantom load” – the trickle consumption even when electronic equipment is off – and bought energy-efficient appliances.

Two things happened: He saw a two-thirds reduction in his electric bill, and he found himself under audit by Mass Electric. The company thought he’d tampered with his meter. “They couldn’t believe I was using so little,” he says.
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Cutting back on electricity used for lighting (9 percent of residential usage nationwide) presents the quickest savings-to-effort ratio. The EPA estimates that changing only 25 percent of your home’s bulbs can cut a lighting bill in half. Incandescent bulbs waste 90 percent of their energy as heat, and compact fluorescents, which can be up to five times more efficient, last years longer as well.

I am far from doing everything I could, but at least I have installed compact fluorescent light bulbs as old ones burned out. Actually I don’t think I have changed a light bulb in several years (another benefit of these energy efficient lights is they last a long time).

Posted by curiouscat
Categories: Economics, Energy, Students
Tags: electricity, Energy, green

Water and Electricity for All

Posted on February 23, 2006 Comments (13)

Segway Creator Unveils His Next Act

Water and Electricity may not seem like something to wish for if you are reading this post. However for over 1 billion people that do without both it is.

Dean Kamen, the engineer who invented the Segway, is puzzling over a new equation these days. An estimated 1.1 billion people in the world don’t have access to clean drinking water, and an estimated 1.6 billion don’t have electricity. Those figures add up to a big problem for the world and an equally big opportunity for entrepreneurs.

To solve the problem, he’s invented two devices, each about the size of a washing machine that can provide much-needed power and clean water in rural villages.

“Eighty percent of all the diseases you could name would be wiped out if you just gave people clean water,” says Kamen. “The water purifier makes 1,000 liters of clean water a day, and we don’t care what goes into it. And the power generator makes a kilowatt off of anything that burns.”
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Kamen’s goal is to produce machines that cost $1,000 to $2,000 each. That’s a far cry from the $100,000 that each hand-machined prototype cost to build.

Quadir is going to try and see if the machines can be produced economically by a factory in Bangladesh. If the numbers work out, not only does he think that distributing them in a decentralized fashion will be good business — he also thinks it will be good public policy. Instead of putting up a 500-megawatt power plant in a developing country, he argues, it would be much better to place 500,000 one-kilowatt power plants in villages all over the place, because then you would create 500,000 entrepreneurs.

More products from his company, Deka Research & Development Corp, including: Hydroflex™ Irrigation Pump, IBOT™ Mobility System and Intravascular Stent.

Dean Kamen understands what engineering can do. “Today, almost 200 engineers, technicians, and machinists work in our electronics and software engineering labs, machine shop, and on CAD stations.”

DEKA’s mission, first and foremost, is to foster innovation. It is a company where the questioning of conventional thinking is encouraged and practiced by everyone—engineers and non-engineers alike—because open minds are more likely to arrive at workable solutions. This has been our formula for success since we began, and it will continue to drive our success in the future.

Dean Kamen founded For Inspiration and Recognition of Science and Technology (FIRST)