UPS with dead batteries reborn as a whole-house power backup

[Woodporterhouse] must deal with regular power black outs in his area. He recently converted a rack-mount uninterruptible power supply to feed a portion of his mains wiring. This one is not to be missed, since he did such a great job on the project, and  an equally remarkable job of documenting it. It’s one of the best examples we’ve seen of how to use Imgur as a project log.

The UPS still needs to have a case, but it doesn’t need room for batteries as he’s going to use a series of high-end sealed lead-acid batteries. So he cut down the enclosure to about half of the original size. That’s it mounted just above the new batteries. For this to work you need some type of transfer switch which can automatically patch between incoming line voltage, and the battery backup. He already had one of these switches in place for use with a generator, that’s it in the upper left. The entire system powers a sub-panel responsible for his essential circuits — the electronics in the home and a few lighting circuits (we’d assume this includes utilities like the refrigerator).

One really great feature that the reused UPS brings to the project is a monitoring card with a NIC. This way he can check the server to see if the UPS is being used, and how much of the 14 battery life remains.

[Thanks Ross via Reddit]

Wind-powered POV weather station

The more we think about this one the more we like it. [Michael] built himself a wind-powered persistence-of-vision weather station. Okay, that sounds interesting, but he ups the ante when you find out what’s included in the system.

A stepper motor acts as the generator which powers the electronics. As we’ve seen before; if you spin the shaft of a stepper motor electricity is produced. [Michael] is actually spinning the housing of the motor, with the shaft mounted to the base that holds the weather station in place. This way, the electrical contacts are spinning along with the blades of the generator. By mounting all of the electronics on these blades he gets around the problem of transferring power onto a spinning platform.

A set of LEDs on the end of the blades display temperature and relative humidity readings. A hall effect sensor pulled form an old floppy drive syncs the display with the rotational speed. He’s even got a shunt system which keeps the input voltage at a safe level, and will act as a break in high winds to keep the rotors from spinning out of control. See what we mean? An interesting idea because a fantastic project when you build in features like these!

Check it out, my clothes are electric. No, seriously

Someday you may be able to use your crotch or armpits to recharge that cellphone. Heck, maybe there won’t even be a battery, just a capacitor which gets its juice from Power Felt, a fabric that converts body heat to electricity.

Now we mention the nether-regions because it’s funny, but also because it makes the most sense. Researchers have developed a fabric containing carbon nanotubes used in a way that generates electricity based on a temperature differential. We figure the areas on the body that have high heat loss would be the most efficient locations for the fabric since it is currently extremely expensive to produce (the hope is that mass-production would reduce cost by orders of magnitude). So we think battery-charging briefs are a definite possibility.

What we see here is a nano-scale Peltier electricity generator. It’s the same concept as this candle-based generator, except the increased efficiency of the Power Felt lets your wasted body heat take the place of the flame.

There’s a white paper on the topic but you can’t get at it without surrendering some [George Washingtons].

[via Reddit and Megadgets]

Investigating the generative properties of a stepper motor

You probably know that if you spin a motor (mechanically) it generates electricity on what would normally be the inputs. This can be a problem when you shut off a spinning motor and is the reason that protection diodes are built into motor driver circuits. But [Dino] isn’t interested in driving a motor, he wanted to see what he could do with the electricity generated by spinning a stepper motor.

He built the test rig that you see above for this purpose. In the foreground a 12V DC motor is held in place with an electrical conduit clamp. This connects to the stepper motor being tested using a segment of rubber tube. The DC motor provides a reliable input for his experiments, but could be replaced in the future by a propeller to make it wind powered, or by a water wheel. Check out the video after the break to see what kind of juice [Dino] gets out of it, and how it can be used for powering LEDs, recharging batteries, or driving a motor.

Continue reading “Investigating the generative properties of a stepper motor”

Occupy rigs up human-power after generators are confiscated

Looks like New York’s fire brigade confiscated all of the gas (or bio-diesel) generators from Occupy Wall Street protesters in Zuccotti Park. Apparently the Fire Chief cites the generators as a fire hazard. This seems a dubious claim. One of the shots in the video after the break clearly shows fire extinguishers close at hand, but we’re no experts on fire code. We’d bet the concern is having combustibles around if the scene turns violent… or just wanting to pressure the group with the loss of a heat source.

Instead of going without, the movement received help from a neighboring protest group in Boston. Bicycle power replaces the missing generators as volunteers pedal to produce electricity. Students from MIT plied their skills to help design multiple charging stations that can be used by the community. It won’t be enough to provide heat for the ongoing occupiers, but it does let them charge their electronic devices which helps ensure that current information is still flowing out of this epicenter of activity.

Does anyone have any ideas for hacking up a heat source that won’t ruffle the feathers of local officials? If so, leave a comment. And if you’ve already got a post written up on the topic don’t be afraid to send in a tip about it. Continue reading “Occupy rigs up human-power after generators are confiscated”

Sustainability Hacks: Wind turbine generator

With a little bit of thought put into the build, a wind turbine generator can be one of the greenest ways to generate electricity. Wind power doesn’t require a semiconductor fab lab (unlike solar panels) and doesn’t have very many environmental consequences (unlike hydro power). The Tech Junkies put up a build log of a wind turbine that ended up being a very easy build.

In the interests of sustainability, The Tech Junkies found an old 1.5 HP DC treadmill motor. After measuring the voltage output when the motor was connected to a lathe, they discovered the power output was very linear. With a little bit of calculations, they realized they needed about 1000 RPM to get 20 Volts out of the motor. The team connected an inverter (it’s always cool seeing a power meter run backwards) and started fabricating the blades.

The team found a wealth of info on blade design on this site and following a few guidelines made six blades out of 8″ diameter PVC pipe. An aluminum hub was fabricated and the whole shebang was put on top of a found steel frame.

The Tech Junkies’ build produces 10 Watts of power but they’re looking to increase that to 500 W with the appropriate gearing. A great build that harkens back to this awesome webpage about turbine building and living off the grid.

Sustainability Hacks: Auto-feeding wood-fired generator

Here’s a project that’s hard to categorize. It generates electricity by burning wood. The diamond-plate wrapped column to the right is a magazine that stores the wood, which is gravity fed as pieces below are consumed. The heat is used to drive a power turbine which is responsible for generating the electricity.

This begs the question, is this a sustainability hack? From one perspective it’s burning renewable biomass. Right now that’s wood, but it could be compressed blocks of grasses or wood manufacturing byproducts. So in this sense it is sustainable. Unfortunately it still doesn’t solve the problem of carbon emissions.

The build log for the project is both image and video heavy. You can see the initial prototypes which are not self-feeding, but burn so hot that there’s a nice pink glow to the entire assembly. But by the time they get to the final prototype it’s running much more efficiently, and can put out a peak of over 100 amps!

[Thanks DerAxman]