Dead motor? Think again

While hobby brush motors are pretty cheap now adays, there’s always that feeling of why replace when you can rebuild and reuse. As such [John Carr] presents how to change the brush position in motors to revive a dead motor. So long as the motor dies from natural causes commutator wear, the idea is the brushes can be moved along the axes and fixed to a new portion of commutator that’s not worn at all. [John] also goes through the details of some tricky reassembly, but we think to make this complete a guide on brush replacement and commutator replacement might be in order hint hint.

Making liquid nitrogen at home

If you’ve got some time to scour eBay and $500 sitting around you can build your own liquid nitrogen plant. [Ben Krasnow] figured it all out for you and estimates he can produce a liter of the stuff for around $1.15. The process depends on a membrane to separate nitrogen from the other materials in the air around us and a cryocooler to get the gas cold enough to condense into a liquid. Other than atmospheric air, you need to pump in electricity. About 9.6 kWh per liter… yikes! Is your human hair solar panel up to that?

Anyway, once you’re up and running you can make yourself some ice cream or possibly save the world from oily destruction.

[Thanks Chris]

Google unveils API to PowerMeter

Google’s tentacles continue to wrap around every portion of our lives with the addition of an API for their PowerMeter software. The PowerMeter tool works with smart electricity meters to monitor and display power usage in the home. This will allow manufacturers (and hackers alike) to design new devices with the Google interface in mind.

We’ve got an old-fashioned power meter with a spinning dial and no blinking LED. This means we can’t monitor that blink to add our own PowerMeter interface. But if you do have an easy way to grab data from your meter you can design a home system that takes full advantage of Google’s tools.

Ok, who’s going to be the first to have their Google PowerMeter-compatible hack featured on Hackaday?

[Thanks Juan]

Wireless electricity

[Eric Giler] has a talk available over at TED that discusses and demos delivering electricity without wires. Called WiTricity, these methods were developed by a team at MIT a few years ago who were working off of the concepts of Nicolai Tesla. The facts shared about our current energy delivery system are a bit shocking; we’ve spent over $1 trillion in infrastructure and produce more than 40 billion disposable batteries each year.

The demonstration in the video starts about 6:30 into it. At first we see a flat panel television powered wirelessly from about 6 feet away, then the T-Mobile G1 powered from the same distance. The thought of new TVs coming with WiFi and WiTricity standard would mean just hanging it on the wall with no cords to run. We can also image cellphones that have a battery only for backup purposes when you were not near a transmitter.

The power transfer occurs between two coils that resonate at the same frequency and only that frequency. This remind us a bit of Orson Scott Card’s fantasy communications device from the Ender’s Saga.

High voltage cable inspection


Have you ever wondered how they inspect high voltage cables without taking them out of service? Check out this video which offers a glimpse into the life of a professional high voltage cable inspector. There are parts of the job you’d expect—namely perching on the cable like a bird, trying to not fall off—but the part of the job you wouldn’t expect is the suit. This suit is made of 75% Nomex, to prevent it from catching fire, and 25% stainless steel thread, turning the suit into a wearable Faraday cage. Of course, because he’s got a Faraday cage mere millimeters from his skin, the cable inspector spends his workday surrounded by half a million volts.  To avoid electric shock, he equalizes the voltage potential between himself and the line before touching the cable.

Depending on your specific phobias, this video might make your job seem really dull… or really really safe.

[via Gizmodo]

Electric Bandages

Silverleaf Medical products has created an electric wound dressing that staves off infection by killing microbes in an open wound and preventing other germs from getting in.

They call it the CMB Antimicrobial Wound Dressing, and it is made of polyester fabric woven with a proprietary material called Prosit. When the bandage is moistened, the Prosit generates a low voltage, killing germs in the wound. One of these bandages can be worn for 3 days at a time, and their clinical trials indicate that they are highly effective in treating infected wounds. Take a look at their brochure (PDF file) for some informative and stomach-turning before and after photos.

[via Medgadget]

Parasitic power devices

Aside from having a very cool name, parasitic power is an innovate way to recapture already spent power. This power can come in the form of wasted heating or cooling of a building for example. Last week the Southern Methodist University activated the first commercial Green Machine from ElectraTherm. The unit recycles residual heat from the building into electricity. So far, the 50kW Green Machine has exceeded expectations. The company also says owners can recoup the units cost after about three years.

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