Reading Power Use Data with a Webcam and Python

As any hacker will attest to, whenever an important tool is missing, you might as well just build a new one! That’s the position that [Matt] found himself in when he was attempting to measure the power consumption at his parents’ house. He left the transmitter for the power meter at home, and so the logical thing to do was to set up a webcam and a python script to monitor his dad’s power meter instead of going back to get his.

The power meter that he had handy was a GEO Minim Electricity Monitor. He found it very difficult to extract the data directly from this particular meter, so instead of digging into any of the communications protocols int he meter, he set up a webcam in a box with an LED and monitored it with a specially-written Python script. The script is able to see the particulars of the meter, and then reports back to the computer with all of the relevant data. [Matt] has put this code up on his project site for anyone to use.

This is a great workaround that doesn’t involve delving too deep into the inner workings of the meter in question. You could always build your own power monitoring system though, if that’s more of your style!

Homemade Gravity Light Doesn’t Last Long but Proves the Concept!

gravity light

After being inspired by the Deciwatt Gravity light, [Steve Dufresne] decided he wanted to try making his own as a proof of concept.

The Gravity Light by Deciwatt is an innovative device designed for third world countries to help eliminate expensive lighting like kerosene lamps. It has a small weight on a pulley which can be lifted up in under 3 seconds. During its slow descent down the weight provides light for 25 minutes! It’s affordable, sustainable, and reliable. It’s also mechanically impressive, which is exactly why [Steve] decided to try making his own.

He’s using a single LED, a small DC motor, a few pieces of wood, an old bicycle wheel, some bicycle chain, and a few jugs of water. The water is connected to the chain which is looped over the smallest gear on the bike. The generator is then powered by a belt wrapping around the outside of the rim. This gives the motor enough speed to generate electricity for the LED. His current design only lasts for about 3 minutes, but he’s already working on the second iteration. Testing systems like this really give you an appreciation for the effort that must have gone into the real Gravity Light.

Stick around after the break to see it in action.

Continue reading “Homemade Gravity Light Doesn’t Last Long but Proves the Concept!”

Boil Off Some White Gas in the Back Yard


[S Heath] is a Coleman lantern collector. Coleman lanterns can run from a variety of fuels, however they seem to run best with white gas, or Coleman fuel. Store bought Coleman fuel can cost upwards of $10USD/gallon. To keep the prices down, [S Heath] has created a still in his back yard to purify pump gas. We just want to take a second to say that this is not only one of those hacks that we wouldn’t want you to try at home, it’s also one that we wouldn’t try at home ourselves. Heating gasoline up past 120 degrees Celsius in a (mostly) closed container sounds like a recipe for disaster. [S Heath] has pulled it off though.

The still is a relatively standard setup. An electric hot plate is used to heat a metal tank. A column filled with broken glass (increased surface area for reflux) rises out of the tank. The vaporized liquid that does make it to the top of the column travels through a condenser – a pipe cooled with a water jacket. The purified gas then drips out for collection. The heart the system is a PID controller. A K-type thermocouple enters the still at the top of the reflux column. This thermocouple gives feedback to a PID controller at the Still’s control panel. The controller keeps the system at a set temperature, ensuring consistent operation. From 4000 mL of ethanol free pump gas, [S Heath] was able to generate 3100 mL of purified gas, and 500 mL of useless “dregs”. The missing 400 mL is mostly butane dissolved in the pump gas, which is expelled as fumes during the distillation process.

Continue reading “Boil Off Some White Gas in the Back Yard”

How can the net amount of entropy of the universe be massively increased?


The greatest – and last – question that will ever be asked is, “How can the net amount of entropy of the universe be massively decreased”. It follows then, that the worst – and possibly first – question ever asked is, “How can the net amount of entropy of the universe be massively increased?” While for the former question there’s insufficient data for a meaningful answer, we’ve found the answer to the latter question. It’s a machine designed to waste energy, and the exact opposite of a perpetual motion machine.

The machine is set up along two stories of a building, with cables, pulleys, and levers constantly pressing an elevator button. The device is powered by the elevator doors opening, so when the elevator opens of the first floor, the part of the machine on the second story calls the elevator. This repeats ad infinitum.

Wait. It gets better. Inside the elevator car, there’s a modified printing calculator also powered by the elevator doors. Every time the doors open, it calculates the amount of energy consumed for each cycle of the elevator. It’s a hydraulic elevator without a countersink, so moving down is effectively free, but each cycle of the elevator still uses up 11.8 Kilojoules of the universe’s energy. To make the build a complete waste of resources, the printing calculator neatly empties it’s printed tape into a wastepaper bin.

We’re tempted to call this a [Rube Goldberg] machine, but that doesn’t seem to fit this machine that does absolutely nothing. Calling it a useless box is more fitting, but this is far, far more impressive than a box that turns itself off. Whatever it is, you can see a video of it in action below.

Continue reading “How can the net amount of entropy of the universe be massively increased?”

Scavenging ambient electromagnetic energy


At this very moment, unseen radio waves are bouncing off almost everything that surrounds you. Emitted by everything from radio and TV stations to cell phone networks and satellites, these waves are full of unharnessed energy. That is, until now. Researchers at the Georgia Tech School of Electrical and Computer Engineering have been working diligently to harness this unused energy, and recently unveiled their new antenna technology at the IEEE Antennas and Propagation Symposium.

The team, led by professor [Manos Tentzeris] has been working to develop ultra-wideband antennas to tap into the energy all around us. Using printers filled with a specially-formulated ink compound, they have been able to print these antennas on paper and polymer substrates. The antennas can harness energy stored in radio frequencies ranging from 100 MHz all the way up to 60 GHz, depending on the printing medium.

The team can currently power temperature sensors using television signals, and is preparing a demo in which they will power a microcontroller simply by holding it up in the air. The technology is still in its infancy, but the list of applications is almost endless. We doubt you’ll be powering your TV with this technology any time soon, but it definitely holds promise for things such as wireless sensor mesh networks and the like.

[Thanks, morganism]

Power All Over Your Body

We know that you can transform the mechanical motions of your body into electrical energy, like when you turn the crank or shake a mechanically-powered flashlight. These types of mechanical motions are quite large compared to many of the day-to-day (and minute-to-minute) actions you perform–for example walking, breathing, and thumb wrestling.

What if we could harvest energy from these tiny movements? Researchers at the Korea Advanced Institute of Science and Technology are seeking the answer to this question with piezoelectric barium titanate. The electrical output of their devices is very small (in the nanoAmps) but over a long period and over many repetitions it would be possible to run a small electric device–even a biologically-embedded one. An alternative to blood power?

There is clearly a lot of potential in this technology, and we’ll be interested to see if and when we can start messing around with this stuff. Heck, it’s already been used to power a small LED and you all know just how much everyone would jump at the chance to cover themselves in self-powered LEDs…

You’ll shoot your eye out, another coilgun

All we needed to read was 4x 3900uF capacitor bank to know we had yet another decently sized homemade coilgun on our hands. And for the math buffs, that equates out to 1.25kJ of potential energy (efficiency kills it down to 37j of kinetic, but large numbers are more fun) which is more than enough to break skin; of course we recommend you just shoot old electronics rather than friends. On the more technical side, sure its only a single stage for now and we’ve seen some slightly more impressive triple stage guns, but it may just be more beautiful than our previously featured coil pistol. You guys be the judge. Catch a complete video after the jump of the internals and build process, skip ahead to 2:40 for the destruction.


Continue reading “You’ll shoot your eye out, another coilgun”