Sustainability Hacks: Automatic Window Control

September 29, 2011 by Brian Benchoff 43 Comments

Sometimes, changing one little bit of a green hack turns it into a build that wastes as much energy as our gaming rig. [Dr. West]’s automatic window controller is one of these builds. The good news is the window controller can be easily modified to cut energy costs in the fall and spring.

[Dr. West] doesn’t have any control over the heat in his apartment and for the entire Canadian winter, his apartment gets really hot. He doesn’t pay for his heat, so he does what any of us would do – crack a window. Inspired by this post, he put a linear actuator in the frame of his kitchen window. [Dr. West] didn’t want to damage the window frame, so he attached the actuator to a piece of square aluminum tubing that mounts to the existing screw holes.

The electronics, [Dr. West] used a Rabbit 2000 dev board, LCD display and keypad, and built an H-bridge circuit on a bit of breadboard. Because of a port conflict and admitted laziness, an Arduino is used to read the thermistor. The display shows the current and desired temperature, and the Rabbit opens and closes the window accordingly. All the source code is posted in the forum post.

While it’s not the most ‘green’ idea to dump heat from a building’s HVAC system out into a frozen tundra, this would be a great build to automatically open and close windows in the more temperate seasons. Open windows during the day, close them at night and you’ll have no more problems coming home to a house that’s either too hot or too cold. Check out a video of the automatic window after the break.

Continue reading “Sustainability Hacks: Automatic Window Control” →

Sustainability Hacks: Solar Battery/smartphone Charger

September 28, 2011 by Mike Szczys No comments

[Michael] took a battery charger meant to be connected to mains power and converted it to work with a solar panel. This was a traditional 4 cell charger which charges the batteries in pairs. He kept that functionality, but added USB charging with a special over-current feature. That’s because his Android phone has a fast and slow USB charging mode. The slow mode makes sure that it draws 500 mA or less to stay within USB specifications. But the fast mode draws more current when the phone detects that the USB connection is attached to a wall charger. [Michael] added a switch that patches a pull-up resistor to the data line, signaling to the phone that it’s okay to switch to fast charging mode.

As for the power supply itself, you can see that [Michael] snapped off the part of the circuit board that housed the original regulator. He’s added his own 5V switching regulator which offers a wide input voltage range. This is connected to two banana plug sockets which can be connected to the solar panel.

Sustainability Hack: Wind Turbine Battery Charger

September 27, 2011 by Mike Szczys 16 Comments

Hit your parts bin and set aside an afternoon to build a wind turbine that recharges batteries. You can see two AA batteries hanging off the side of this small generator. You only need a few parts to make this happen, and chances are you have them sitting in your junk bin already.

The generator itself is a small stepper motor which can be pulled from a floppy disk drive or a scanner. The blade is cut from a single piece of 3.5″ (90mm) PVC pipe, with another piece of smaller-diameter pipe serving as the body of the turbine. The tail-fin makes sure it’s always pointing into the wind and was made from some plywood. As the blade spins, a current is induced on the control pins of the stepper motor. By building a pair of bridge rectifiers and using an RC filter you’ll get the most out of the generated current.

This turbine can charge a pair of NiCad batteries in about 10 hours, but it might be worth developing some smart circuitry to manage charging. If it were able to choose between a dedicated storage battery and the on-board battery holder you could put all of the wind energy to good use.

[Thanks Michael]

A Solar-Powered Automatic Chicken Coop

September 21, 2011 by Jeremy Cook 21 Comments

Although we’ve featured many chicken-related hacks here, this chicken coop features a solar-powered door to save one from having to open up the coop in the morning. As [chrisatronics] puts it “keeping chickens has one major drawback: You have to get up with them in the early morning and open the door at the coop. Everyday. Including Sundays and holidays.” This would help explain why so many people seem to be hacking their coops.

Solar power may be an interesting idea in itself, but when coupled with the fact that a chicken coop isn’t necessarily near a power supply, this becomes a very expedient solution. Controlling the setup is a MSP430 microcontroller (programming featured here for Linux) with a salvaged windshield wiper gearmotor. [Chrisatronics] did a great job writing this hack up, so if you want to try this yourself, make sure to check out the article.

Also, don’t forget to check out the video after the break for the ‘coop in action! Continue reading “A Solar-Powered Automatic Chicken Coop” →

Grow Your Own Fresh Salad Year Round With This Cheap Hydroponic Setup

September 16, 2011 by Mike Szczys 53 Comments

With fall approaching you might think about moving your gardening inside. [Jared] used cheap and readily available materials to make these salad-green trays. When used with his grow lights and tent (which he built during a different project) he was able go from seed to salad-bowl in just four weeks.

A pair of plastic storage bins act as the base, keeping the water right where it should be. Some holes cut into a piece of solid foam insulation holds a set of plastic pots in place, allowing the water to leech into the Rockwool that holds each plant in lieu of soil. To aerate the water [Jared] grabbed a cheap aquarium pump, splitting the output into several different branches. Each has its own check valve to ensure that a pump failure doesn’t let the water find its way out of the plastic tube. A set of bubble stones breaks up the output, helping to mix it with the water.

This isn’t quite as easy to pull off if you don’t already have a grow light. But you can always make it worth the investment if you decide to start next summer’s garden from seed. Or perhaps you can try to make your own using a varation of this shop lighting hack.

[Thanks Jayson]

Engine Hacks – A DIY Methane Generator

September 11, 2011 by Jeremy Cook 19 Comments

All “methane generator” jokes aside, This one actually serves a useful purpose. Although not an engine hack per se, methane can be used to run an engine. As the traditional method of powering an internal combustion engine, gasoline, gets more and more expensive, alternatives will have to be found. If you happen to live on a farm, or have access to a source of organic waste, this method could serve as a viable one.

One would need quite a bit of waste, as each kilogram yields around 400 liters of methane gas. This amount is enough to run a gas light for around 4 hours. Any sort of useful engine would require quite a bit more than this (chicken farm possibly?).

A process for converting waste to fuel is illustrated in the video after the break. Extreme caution should be used if attempting to do something like this. There is a danger of not only flammable gas leaking and catching on fire or exploding, but the organic material can be quite toxic as well. Continue reading “Engine Hacks – A DIY Methane Generator” →

High Efficiency Solar Charger Circuit Tops Off Those Lead-acid Batteries

September 10, 2011 by Mike Szczys 21 Comments

Make your next project solar-powered with this charging circuit. It’s completely through-hole, and there are no microcontrollers that need to be flashed. If you can source parts and are handy with a soldering iron building this will be a breeze.

Both the maximum system voltage and the low voltage drop out are configurable. After assembly, you just need to attach a regulated power supply to the load terminals. Tune the power supply to the max voltage and turn a potentiometer until an LED comes on, then repeat the process for the drop out voltage. Board artwork for the two-sided PCB and a schematic are available from the page linked at the top. If you’re not into etching your own circuit boards you can buy one for around $10.

[Thanks Murray]