[vimeo http://vimeo.com/6409575 w=470&h=352]
[Pete], a musician, and the guy behind SparkFun’s pogobeds and locking footprints has a sprinkler hack. He wanted to keep his dog, Choppy, happy with a green lawn while also keeping his sidewalk water free. To solve this problem, he hacked his sprinkler and hose to adjust the sprinkler’s range. He uses an Arduino to read a potentiometer signifying the direction that the sprinkler is facing and a servo to adjust a hose valve that controls the sprinkler’s water flow. Be sure to check out the video above to see it in action.
green hacks850 Articles
Wireless Electricity
[ted id=619]
[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.
Energy Efficient Fridge Hack
We’ve already covered a pipe bomb mini-fridge this week, but inventor [Tom Chalko] provides us with today’s fridge hack. He noticed that chest-style (laying down, see above) freezers were more energy efficient when compared to normal stand up refrigerators at the same size, despite the colder temperatures involved. This is largely due to the fact that these chest-style freezers keep cold air in like water in a bowl, even if the lid is open. He has written a very thorough report on his findings (pdf), as well as a detailed walk through of the manageable task of converting a chest-style freezer into a chest-style fridge. In the end, his fridge only used 103 Wh of electricity on the first day to reach and maintain between 4° and 7° C (39° to 45° F), and he noted that 30% of that was just getting it up to temperature. After that, the fridge only turned on for roughly 90 seconds an hour, making it a very quiet fridge as well.
