Firefly cap has no battery and is meant for indoor light harvesting

May 7, 2012 By Leave a Comment

[Michael Ossman] wrote in to show off his newest project. He calls it the Firefly cap, which we think is something of a play on words. You can see that it serves as the cap of a Mason jar, but it also uses a supercap instead of a rechargeable battery.

Posts about firelfly jars go way back. And [Michael] mentions that a similar firefly project was his first embedded project. The concept uses LEDs suspended in a jar. When a light detector senses the target level of darkness, the lights inside begin to twinkle like their insect namesakes.

We like this design for two reasons. It’s aimed at collecting light in an indoor environment so you don’t have to worry about placing it in the sun. And it uses a super capacitor instead of a battery so this should truly keep going and going without wearing out the energy storage components. We also like the fact that although this is a Kickstarter project, everything you need to build your own is already available at the Github repository.

Filed Under: Microcontrollers Tagged With: , , , ,

Sun-powered Stirling engine with automatic tracking

May 2, 2012 By Leave a Comment

Check out this solar-powered Stirling engine (translated). The build is part of a high school class and they packed in some really nice features. The first is the parabolic mirror which focuses the sun’s rays on the chamber of the engine. The heat is what makes it go, and the video after the breaks shows it doing just that.

But the concept behind the mirror makes for an interesting challenge. The light energy is focused at a narrow point. When the sun moves in the sky that point will no longer be at an efficient position to power the engine. This issue is solved by a pair of stepper motors which can reposition the dish. It’s done automatically by an Arduino Uno which makes readings from four LDR (photoresistors) in that cardboard tube mounted at the top of the dish. If the light intensity is the same for all four, then the tube is pointed at the sun. If not, the motors are tweaked to get the best angle possible.

[Read more…]

Filed Under: green hacks Tagged With: , , , , , ,

Monitoring a solar array output

April 23, 2012 By Leave a Comment

After years of hoping and wishing [Dave] finally took the plunge and installed solar panels on the roof of his house. He’s got twelve panels that are each rated at 240 Watts! But just having them sitting there and pumping power back to the grid isn’t enough. Understandably, he decided to add his own solar array monitor so that he could see just what those babies are bringing to the party.

The solar array has an inverter which takes the DC from the cells and converts it to mains voltage AC for use on the grid. The system includes a panel meter which you’d normally find on the supply to the house. All he needed to do is find a way to grab the data from that device. It’s an Elster meter, and offers two types of feedback: a blinking LED that corresponds to each Watt-hour passing through the meter, and an IrDA port which provides a more error-proof method of reading data. Monitoring the 1 Wh pulse is quite a popular method for keeping track of your electric meter, but if your hardware misses a pulse the data will be off. [Dave] chose to use a light sensor to monitor the IrDA output, which is encoded data. As long as you can read the protocol, which has been published by Elster, a transmission can be missed now and again without disturbing the overall power consumption data.

Filed Under: green hacks, home hacks Tagged With: , , ,

2 horse power 3 wheeled beast

April 19, 2012 By Leave a Comment

This beast above is the result of what is probably the coolest class project ever.  The instructors[Michael Ham] and [Kenny Ham] gave their students a pile of junk and said “build something”. The goal was a “vehicle that could recharge itself”. In the pile were motorcycle tires, an old classroom seat, the front suspension from a VW bug, some old power drills, a solar panel, and a battery, amongst other bits and pieces.  What you see above was the result.  While it may not win any drag races any time soon, it was a fantastic class project that had the students thinking their way around many problems.

The videos on the project page show that this thing isn’t quite as sluggish as we would have expected for its size.

[via Make]

Filed Under: solar hacks, transportation hacks Tagged With:

Resurrecting a cellphone with blown USB circuitry

March 27, 2012 By Leave a Comment

[Script] is pretty lucky. One of the engineers who designed his cellphone included over-voltage protection in the circuit. Of course you probably wouldn’t know about this if there wasn’t a service schematic available. But a bit of searching around let him resurrect the fried USB segment of his Nokia N900.

Now [Script] has been experimenting with portable solar power like the system featured at 25C3 a few years back. Unfortunately he made an error which routed 12V into the USB connector’s 5V rail. After this unfortunate mistake the phone would not longer connect via USB, or charge the battery. Luickly the N900 is a favorite with the hacker community (you can see all kinds of N900 related projects here at Hackaday) and [Script] found his way to their N900 Schematic page. Digging into page four he found part F5300 which is labeled 2.0A. He removed the PCB and shielding, and tested the part with a multimeter to confirm it was blown. A quick wire bridge got the phone charging again, but [Script] plans to position a new fuse as soon as he can source the part.

Who says these devices aren’t user serviceable? If we could just get our hands on more service schematics perhaps our gear would last longer.

Filed Under: cellphones hacks, repair hacks Tagged With: , , , ,

The Pirate Bay aims for the clouds…literally

March 21, 2012 By Leave a Comment

tpb

There is no shortage of government and entertainment-related agencies chomping at the bit to shut down the Pirate Bay for good. While the group has not suffered a permanent service ending raid like [Kim Dotcom] and the Megaupload crew, they are always thinking up novel ways to ensure that the site can endure whatever law enforcement throws at them.

In a recent blog post, representatives from the group unveiled plans to put their front line servers in the clouds, courtesy of custom-made autonomous drones called “Low Orbit Server Stations.” The project is in its infancy, but the general idea is to mount small computers like the Raspberry Pi on GPS-controlled drones kept aloft 24×7 (presumably) using solar energy. These drones would communicate with clients on the ground via radio transmitters which they state can provide a “100Mbps node up to 50km away”.

Calling the claims grandiose would be an understatement, but then again the Pirate Bay has proven to be a difficult organization to quash in any substantial way, so only time will tell.

[via The Daily What – Thanks, roboman2444]

Filed Under: news Tagged With: , , ,
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