A Quick History Of The Battery

[Colin] tells us it all started with [Benjamin Franklin]’s battery of capacitors. It was a bunch of leyden jars hooked together in series and there wasn’t even chemistry involved yet, but the nomenclature stuck and it wasn’t long before it evolved into the word we use today.

For the word to change, things got chemical. [Alessandro Volta] introduces his voltaic pile. Once scientists latched onto the idea of a stable reaction giving a steady stream of magic pixies for them to play with, it wasn’t long before the great minds were turning their attention to improving this new technology.

In the classic game of one-upmanship loved by technical people all over, we quickly skip forward to the modern era. An era where no man is unburdened with the full weight of constant communication. It’s all thanks to a technology that’s theoretically unchanged from that first pile. Video after the break.

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Protecting Your Home Against Potato Invaders

Not sure where the potatoes were sneaking in, [24Gospel] did what any decent hacker would do: strapped a camera to a Raspberry Pi, hacked a bit on OpenCV, and built himself a potato detection system. Now those pesky Russets can’t get into the house without tripping the tuber alarm.

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OK, seriously. [24Gospel] works for a potato farm as a systems/software developer. (How big does a potato farm have to be to require a dedicated software guy?) His system is still a first step, but the goal is to grade the potatoes, record data about size and defects, and even tell different potato types apart. And he’s found decent success so far, especially for the money. We don’t often build projects that need to operate in hostile environments, but we appreciate the nice plastic case and rugged adjustable steel frame that supports the Pi and camera over the sorting bed.

Even more, we applaud the hacker spirit here. [24Gospel] is obviously working in a serious production environment, but still he’s trying out new things in an attempt to make it work better. While it would be impossible to quantify the impact of this kind of on-the-job ingenuity, we bet it’s not insignificant. Why don’t we see more documented workplace hacks around here? Would the unsung heroes please stand up?

[via /r/raspberry_pi]

Hackaday Prize Entry: Humidifeyes

Most of the entries in the Hackaday Prize Assistive Technology challenge solve an obvious problem. 3D printed prosthetics, a computer mouse for the mouth, and text to speech systems all have obvious uses. For his Hackaday Prize entry, [spandana] decided on something a little less obvious. He’s going after the scourge of dry eyes with Humidifeyes.

The problem of dry eyes seems a bit esoteric at first glance, but [spandana] is specifically designing this device for people with Steven Johnson’s Syndrome. It’s been mentioned that LASIK patients have dry eyes for months. There is, apparently, an opportunity here.

The mechanics of the device are pretty simple. The current prototype uses off the shelf safety glasses with a little foam around the edges as a chassis. Moisture is delivered from a reservoir to an ultrasonic vibrator. This is a very effective way to atomize liquids, and is small enough to fit on the frame of a pair of glasses.

Although this is the sort of project that’s just a bit weird and allows for too many puns, there’s the glimmer of something useful in here. Dry eyes are a problem, and short of a bottle of Visine, there’s not much to do about it.

Glow-In-The-Dark Antenna Helps You Spot Your Car At Night

It’s late, and you’re lost in a sea of cars trying to remember where you parked. If only your vehicle had a glow-in-the-dark antenna to make it easier to find, you wouldn’t be in this situation. Faced with just such a problem himself, Instructables user [botzendesign] has put together a handy tutorial to do just that.

[botzendesign] first removed the antenna and lightly abraded it to help the three coats adhesion promoter do its job. A white base coat of vehicle primer was applied — lightly, so it doesn’t crack over time — and once it had set, three coats of Plasti Dip followed. Before that had a chance to dry, he started applying the glow-in-the-dark powder, another coat of Plasti Dip, repeating four more times to ensure the entire antenna had an even coat of the photo-luminescent powder and then letting it dry for 24 hours. Continue reading “Glow-In-The-Dark Antenna Helps You Spot Your Car At Night”

Try Not To Look At This Giant Plasma Tube

Everybody loves plasma globes, but if you are like [zrgzhv], building them as large as possible is the challenge! Definitely a beautiful project, at 7 feet long and 1 foot in diameter, this monster tube makes an impressive display of plasma filaments that slowly move inside. Heck, they almost seem to be alive following the movements of his hand and it’s hard not to become mesmerized by the motion.

seven-foot-plasma-tube-thumbThis tube follows the same principle of operation as its smaller cousin, the plasma globe. Air is evacuated and the tube is filled with a mixture of noble gases, with the particular mixture being responsible for the color of the filaments. Then, high voltage AC is applied to an electrode, which causes the moving tendrils of colored light to extend from the electrode to the outer glass, a phenomenon known as glow discharge. In general, gas-filled tubes can have other uses such as lightning — in the form of fluorescent, neon and xenon lamps — or high power switching as in the thyratron tube, among other applications.

The tube has a weight of over 65 pounds, and needs 300 watts of power to operate from an also homemade power supply. In another video, you can see 10 tubes of different colors working at once. Plasma always makes a great attention-getter; another nice example of its use can be seen in this steampunk lamp which incorporates rotating contacts on the outside of the glass.

Bending The Light

Ruled Hyperboloid CC Prof. William McCallum
Ruled Hyperboloid CC Prof. William McCallum

Everyone knows you can’t visibly bend light over short distances in free air. Or can you? [Jack Pearse] has figured out a way to do it though, or at least make it appear that way. He does it by combining a trick of math and a trick of the eye. The secret is the hyperboloid, a geometric construct described by a quadratic equation. [Jack’s] creation is more specifically a hyperboloid in one sheet. This type of structure allows straight lines to create a an overall curved surface.  Hyperboloids have been used by architects and in construction for years, often in tall structures like water towers.

If a bunch of straight steel beams can form a curved shape, lasers should be able to pull off the same effect. By employing persistence of vision, [Jack] was able to create his hyperboloid with only 10 small lasers. The lasers are mounted on the rim of a bicycle wheel and carefully aimed. The wheel is spun up with using an electric bicycle motor. [Jack] kept things safe by building a centrifugal switch. The switch powers up all the lasers in when the tire is spinning. This ensures no one can be hit by a static beam.

Once the wheel is spinning, all you need is a bit of smoke or haze in the room. The spinning lasers combine to form the hyperboloid shape. You can see the project in action in the video after the break.

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Don’t Make Your Battlebot Out Of A Pumpkin

It’s that time of year again. The nights are getting longer and the leaves are turning. The crisp fall air makes one’s thoughts turn to BattleBots: pumpkin-skinned BattleBots.

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Kids these days can’t even draw without a computer

If you’re asking yourself, “could a laser-cut plywood bot, sheathed in a pumpkin, stand up against an all-metal monster”, you haven’t seen BattleBots before. Besides the hilarious footage (see video embedded below), a lot of the build is documented, from making a CAD model of a pumpkin to laser-cutting the frame, to “testing” the bot just minutes before the competition. (That has to be a good idea!)

The footage of the pumpkinbot’s rival, Chomp, is equally cool. We love that the hammer weapon is accelerated so quickly that Chomp actually lifts in the air, just as Newton would have predicted. We’re not sure if the fire weapon is good for anything but show, and facing plywood pumpkinbots, but we love the effect.

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