Despite this being [Kenneth Finnegan’s] first Burning Man, the guy came prepared and stayed connected by setting up a beefy electricity supply and a faint yet functional internet connection. If you saw [Kenneth’s] Burning Man slideshow, you know that the desert is but a mild deterrent against power, water, and even temporary runways.
He borrowed a 20V 100W solar panel from Cal Poly and picked up a bargain-price TSMT-20A solar charge controller off eBay. The controller babysits the batteries by preventing both overcharging and over-discharging. The batteries—two Trojan-105 220Ah 6V behemoths—came limping out of a scissor lift on their last legs of life: a high internal resistance ruled out large current draws. Fortunately, the power demands were low, as the majority of devices were 12VDC or USB. [Kenneth] also had conveniently built this USB power strip earlier in the year, which he brought along to step down to 5VDC for USB charging.
Internet in the desert, however, was less reliable. A small team provides a microwave link from civilization every summer, which is shared via open access points in 3 different camps. [Kenneth] pointed his Ubiquiti NanoStation at the nearest one, which provided a host of inconvenient quirks and top speeds of 2-20kBps: enough, at least, to check emails.
After the headlight on his bike died, [Patrick] decided this was the best time to hack the remains and solve a few problems: namely a constantly drained battery from accidentally forgetting to turn the light off. He opted for a solar solution, as he already had both an Adafruit solar lithium charger and a Seeed Li-po Rider. [Patrick] picks the Adafruit board for its extra safety features like temperature sensing to prevent the cell from overheating.
The build uses 9 eBay-sourced 2V mini solar panels attached neatly on the bike’s mudflaps. Three groups of 3 panels in series provide the needed 6V into the Adafruit lithium board which safely charges a spare 900mAh Nokia phone battery from the junk drawer. [Patrick] admits this solar setup may be overkill. He decided to include a USB jack to keep his phone charged for some Google maps navigation. The Adafruit board does not step up to 5V, however, so [Patrick] tacks on a Mintyboost kit to kick the Lipo’s output up high enough to charge the phone.
Solar’s not the only alternative way to power your bike’s lights. Check out the RattleGen from earlier this year if you missed it.
Green hacks implement one of two philosophies. The first is über-technical, with very expensive, high-quality components. The other side of this coin creates green power out of junk. [Timot] obviously took the latter choice, building a windmill out of an old washing machine motor and a few bits of PVC.
The generator for the windmill is based on a Fisher and Paykel direct drive usually found in clothes washing machines, rewired to provide 12 Volts at low RPM. At high speeds, the generator can produce 80 Volts, so a charge controller – even one based on a 555 chip – was an excellent addition.
For the other miscellaneous mechanical parts of the build, [Timot] cut the blades of the windmill out of 200 mm PVC pipe and sanded them down a bit for a better aerodynamic profile. With a custom fiberglass spinner, [Timot] whipped up a very attractive power station that is able to provide about 20 watts in normal conditions and 600 watts when it’s very windy. Not enough to power a house by any means, but more than enough to charge a cellphone or run a laptop for a few hours out in the back country.
We’ve seen a few of the projects from The Deconstruction, a 48-hour build-a-thon for hackerspaces and other groups around the globe. Of course Tymkrs, a pair of geeky vloggers famous for their building prowess, were part of The Deconstruction, and in the process they came up with a few really cool builds at their hackerspace, The Rabbit Hole, in Rochester, MN.
Their theme for The Deconstruction was “a zombie apocalypse”. Instead of homemade crossbows and electric fences, Tymkrs and the rest of The Rabbit Hole put a ‘rebuilding society’ spin on the whole zombie apocalypse and ended up building things that would be useful after Z-day.
First up is a PVC bike trailer designed to easily attach to the back of a bicycle. The frame is made out of a few pieces of 2″ PVC pipe with some nylon rope knotted together for a nice webbed platform. a 5/8″ steel rod was turned down to accept two 20″ bike wheels. A useful build, even if it’s not the zombie apocalypse.
The second build is a solar japanese lantern, combining [Addie]’s love of solar lanterns and japanese-style lanterns into one great project. The materials for this build came from a broken solar-powered lantern with completely revamped electronics. There’s a Joule thief to keep the LED lit, and a few solar panels to charge up the batteries during the day. Of course the build wasn’t complete without a little decoration, so [Addie] drew four panels of rabbits for The Rabbit Hole team.
By far the most dangerous build undertaken by The Rabbit Hole is their can crusher. It’s a pair of snowblower tires powered by a disused garage door opener. The theory of operations is that a can will drop in between the rotating wheels, crushing the can, and sending it to a waste basket below the device. In practice, the device didn’t really live up to expectations, but it’s loud and dangerous, so we’ll give it a pass.
Generating power from wind is easy – just stick a windmill on a pole and attach a generator. That’s not particularly cool, though, so [Adrien] and his team from his senior design project are using an autonomously controlled kite to generate power
The basic idea of generating electricity from a kite is to fly it around in figure-eights while unwinding the kite line from a spool. The very strong forces on the kite lines can be used to drive a generator which provides power for reeling the kite back in at a lower angle of attack. You can check out [Adrien]’s kite power theory page for a few more details on how this works.
Right now, [Adrien] and his team have a basic rig set up to generate power and are flying the kite via a joystick. Updates are coming, and you can check out the video of their RC kite in action after the break.
Continue reading “A remote-controlled, autonomous kite generates power”
Steampunker extraordinaire [Jake von Slatt] loves the idea of solar-powered garden lights soaking up the sun’s rays during the day and powering a LED in the evening. Commercially available solar lanterns, as [Jake], you, me, and everyone else on the planet have discovered, are universally terrible and either don’t have solar panels large enough to charge a battery, or only last a year or so. [Jake]’s solution was to make his own solar lanterns and in the process he came up with a great way of cutting his own solar panels.
[Jake] turned to ebay to source 100 3″ x 6″ solar panels for about $30. These are broken panels, factory rejects, but still are able to produce the 0.5 Volts they should. Since these are rather large panels for a solar lantern, [Jake] needed a way to cut these panels into manageable sizes.
To cut the panels, [Jake] made a box to fit a Dremel with a right angle attachment and a port for a vacuum cleaner. There’s a sled for the panels with markings at 40, 80, 75, and 150 mm so the panels can be quickly cut to size with a diamond cutting wheel.
After the boards are cut, [Jake] checks them out with a multimeter to be sure they’re producing the half volt they should. After that, it’s a simple matter of soldering them together and adding them to his solar lanterns.
[Paulo]’s got a few solar panels on his shed, and while he does have a fairly nice setup with a battery charge controller, he found himself looking around for a panel voltmeter. Of course you can buy a panel voltmeter for under $20, but [Paulo] wanted something that fit his 4-4-4 plan; his voltmeter should cost under $4, draw less than 4mA, and last for 4 years. The jury is still out on the 4 year qualifier, but he did manage to meet his other goals by repurposing a dollar store pedometer as a voltmeter.
The pedometer in question is a very simple device. After inspecting the PCB, [Paulo] found it operates by looking at a trigger pin and incrementing the number on the display each time the circuit closed. [Paul] designed a very small PIC12F-powered circuit that reads the voltage of his batteries and triggers the pedometer’s LCD for every 10th of a volt. To display 12.6 Volts, [Paulo]’s code triggers the LCD 126 times, for example.
After wiring up the reset button so the display will go back down to zero for each new reading, [Paulo] encased his new volt meter in a plastic box. It’s not exactly a fast way of measuring voltage, but seeing as how that won’t change very fast, it’s the perfect solution for [Paulo]’s solar charger setup.