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.

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.

[Thanks 1116 Birchmont]

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.

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]

[Glenn] from The Back Shed has built a lot of windmills and stationary generators over the years, but recently decided to try his hand at building something a bit more portable.

The charger is based of a relatively simple design, employing a 5.2 HP Kubota 4 stroke motor and a 12v car alternator to provide power. While you might be inclined to point out that his charger does exactly what an alternator and motor are built to do, there was a bit more to it than simply slapping the two parts together.

A laser cut adapter plate holds the motor and alternator together, but once [Glenn] wrapped things up and gave the motor a spin, he realized that he was driving the alternator backwards. This would eventually cause the alternator to overheat since the cooling fan was running the wrong way. He removed the fan and reversed the fins with a hammer so that he could get the cooling he needed without having to reinstall the alternator in the opposite orientation.

The whole kit was mounted on a hand truck for portability, and [Glenn] says that the charger/generator only needs to run about 5 minutes before a dead battery has enough juice to crank an engine.

[via HackedGadgets]

Reader [Andre] sent in a link which tells us all about this “cool” Copper Oxide Thermoelectric Generator. All you need is a bit of solid copper wire and a gas torch. Burn the wire so it gets a nice coating of oxide. From there, it is a matter of making the 2 sections of burned wire cross at a point and heat up only one of the wires. Whichever is hotter forms a cathode and whichever one is cooler is the anode.

Just one of these junctions is enough to produce a few hundred millivolts, but the author takes it a step further, well 16 steps further. He made a ring of these junctions in series, which is enough to light a bright blue LED. While the author notes that this thing is producing a considerable amount of voltage, its not producing much amperage. This could come in very handy in the future, like if you need some additional LED lighting for your camp stove.

We’ve all heard of solar cells that charge your devices, or the odd flashlight that charges when you shake it, but this style charger should be new to almost everyone. This “pan charger” is reportedly capable of charging a cell phone or other mobile device using a USB connection in 3 to 5 hours.  It also has a built-in radio and lantern. This should be a great tool for surviving a zombie apocalypse or if you simply live in a region without readily available power.

A second charger, currently being used in Africa, is an adaptation of a small generator hooked up to a bicycle. As this form of transportation is quite common in developing nations, this simple idea definitely shows promise.  Check out the video of the bike cell phone charger after the break.

via [labnol.org]

You can build a copy of this vertical wind turbine in a weekend and it won’t cost you all that much. Applied Sciences developed the hardware and they’re sharing all for the build details. You will be taken through every part of the build starting with the fin assembly which is made from stove-pipe material. This is a perfect raw material because it is already curved and suited for aerodynamic use in much the same way that PVC pipe is for making fins and we would expect it to be a bit lighter in weight. You will also need to turn your own coils when assembling the stator. This particular build process uses nine coils embedded in fiberglass. They remain stationary while two different discs, each containing a dozen rare earth magnets, rotate in close proximity to induce a current. It outputs three-phase AC current which can be turned to DC using a bridge rectifier and then further regulated for storage in batteries.

[Thanks Miguel]

[Ben Nelson] turned his electric Geo Metro into a plug-in hybrid. But wait, where’d he get an electric Geo Metro? It seems that we’re one hack behind [Ben], who converted the vehicle to all electric back in 2008 using a forklift motor and some batteries. This time around he’s following the Chevrolet Volt’s example by adding a backup generator. Instead of going with a gasoline power he added a tank of propane and the generator from a Recreational Vehicle. This won’t put out enough juice to drive while the generator is running, but you can use it to extend your traveling range by pulling over for a nap while it tops off the batteries.

[Scott Nietfeld] built a charger from a Dyna-flex wrist exerciser. We hadn’t heard of a these gyroscopic devices before but once we saw the promo video (embedded after the break) we realized that this is the kind of thing that infomercials were made to sell. [Scott] knew the internals spun to fairly high RPM and figured that adding a few magnets on the inside and coils on the outside would turn this thing into a generator. Four rare-earth magnets fit the bill, with two external coils feeding a rectifier and linear regulator. Below you can see his demonstration video where he takes the orb apart, then spins it up, generating 250 mA at about 7.5 volts to drive the regulator and charge a cellphone. Not bad!

Dyna-flex promo video

[Scott's] walkthrough video:

What weighs more than 500 pounds, produces 500 kilovolts, and we don’t recommend you try at home in any way shape or form? If you guessed a rock disaggregation device, you’re correct! We also accepted lightning generators as correct answers. Using high voltage electricity, a rock can be split apart down to its grains without destroying the precious minerals inside; unlike traditional grinding and mechanical techniques that often ruin the sample. All it takes is a massive hydro pole transformer, five 1uf 100 kilovolt capacitors, eight hand wound inductors, and two massive cojones to stand within 20 feet of the thing while it’s going off. Video after the divide.

[Niklas Roy] wanted to create electricity from moving water so he came up with this hyrdopower generator. It is part of his grand scheme to rent out small personal fountains made from buckets. They need electricity to run so he hooked up the generator to the water jet of a public fountain. It should be possible to use this setup with falling water in a similar way that other generators do.

To build the device he cut fins out of PVC pipe to use as the scoops. They are attached to a Shimano hub generator, meant for producing power while you pedal. The hub is mounted in the front for from a bicycle, which can then be mounted anywhere moving water is available. The only thing that worries us about the setup is [Niklas'] comment that being showered with water didn’t destroy the hub right away.

See the hub and the smaller fountains in the clip after the break.

[Paul] wanted to have access to renewable energy at his cabin. It’s a relaxing place, nestled in a tall forest that shelters him from the sun and wind. This also means that solar and wind energy aren’t an option. But there is a stream running through the property so he decided to build his own version of a small water-powered generator.

He tapped into a reservoir about 200 feet upstream, split the flow into four smaller hoses, and channeled that into a five-gallon bucket. Inside the bucket you’ll find a Pelton wheel he built which turns a low-RPM generator. He manages to generate 56 VDC at 10 A with this setup, more than enough to charge a bank of batteries.

He does a great job of explaining his setup in the video after the break. If you’re looking for other ideas of how to cut down on your environmental impact check out this compost-powered water heater.

[Scott Harden's] prime number generator exhibits a great way to use an LED matrix to present readable information. The project resides in a hinged wooden box with a grid of holes on the lid for the LEDs. [Scott] has overlaid the matrix with a printout showing powers of two that represent different prime numbers. Inside you’ll find an ATtiny2313 microcontroller that handles the column scanning and prime number testing. We’ve embedded a video the break where [Scott] explains the project in great detail, but you should also check out his prototyping and construction pages.

[Tyler LaVite] tipped us off about the generator he built. He combined a 5.5 horsepower Honda motor with a 10 horsepower electric bandsaw motor. To get an induction generator to produce alternating current you must feed electricity into the system to start the magnetic flux. [Tyler's] solution was to include a bank of capacitors totaling 230mF which charge from the motor, then release back into the system. It’s not as green as the syngas generators we’ve seen since it still uses fossil fuel, but it reuses old parts sending less to the landfill.