20 Kilovolts Replaces Push Pins On This Bulletin Board

November 10, 2011 by Mike Szczys 89 Comments

Electrical Engineers don’t need push pins. That’s because they know how to control electrons! [Sven] put his knowledge of these subatomic particles to use when building his high voltage bulletin board. It uses a set of vertically strung wires to keep paper pinned against the board. The wires have high voltage at low current travelling through them. They’re in front of the board, but not touching it, and the board is serving as a ground plane. In this way an electrostatic charge pushes (or should that be pulls?) against the paper to keep each sheet right where he places it.

In the video after the break [Sven] gives us a tour of the hardware at work here. It starts with a 12V psu which feeds a buck converter. The regulated feed is patched into a high voltage supply which was designed as a CCFL driver. Finally, a voltage doubler is used to reach the final voltage, measuring about 20 kV per wire.

Don’t worry, [Sven] says the bare wire is “almost completely safe” because of the low current being conducted.

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Bullhorn Mod Lets You Disperse Angry Crowds To The Dulcet Tones Of [Kenny G]

November 10, 2011 by Mike Nathan 11 Comments

megaphone-mod-aux-audio-in

[Randy] had a cheap megaphone, and like most models in this price range, it didn’t have an audio input jack on board. He wanted the ability to pipe both music and audio from an external mic through the megaphone, and in a brief tutorial, he shows how he modified his bullhorn to do just that.

Most megaphones carry their electronics near the built-in mic, just outside the battery compartment. Removing the screws from the cap in [Randy’s] model revealed a circuit board and a couple of wires connecting it to the on board mic. His megaphone happened to play some canned music from a secondary circuit board, and he spliced in an audio jack with a built in cutoff switch between that and the main PCB. He also added a resistor in between his jack and the microphone circuitry to attenuate the line level signal properly. Once he reassembled everything, and then tested his input using a portable audio player, slowly ramping up the volume to the desired level.

It’s not every day that you require the ability to blast music through a bullhorn, but [Randy’s] modification is a great addition when you do need it.

Hacking A VS200 Food Sealer

November 9, 2011 by Jeremy Cook 22 Comments

This food sealer just wasn’t cutting it for [Tinkering Engineer], so he decided to do something about it. The issue with this sealer was that it didn’t have a mode where it could simply seal bags without pulling a vacuum on it. Going through the whole process takes a reported 40 seconds in order to evacuate the air and then seal the bag. Without pulling a vacuum, the sealing process took only 9.

After taking everything apart and looking around, a PIC microcontroller, and vacuum switch were found as well as other assorted electronics. Although the first thought was to replace the onboard PIC with an Arduino, a much simpler solution was arrived at. Two switches were added, one to disable the vacuum pump and the other to manually turn on the heater. This would allow the machine to function as originally intended or simply let bags be sealed without the vacuum function.

This hack may not be the most advanced one that we’ve ever seen, but it’s a good reminder that some projects can be done very simply if you’re willing to look around!

A Tesla Coil That Delivers Shocking Candy

November 8, 2011 by Mike Nathan 9 Comments

shocking-candy-tesla-coil

Even though Halloween was a week ago, we are still seeing plenty of cool stuff coming our way. Take for instance this Tesla coil that [JJ] sent us.

He got the idea to build a coil for his Halloween display about a week before the event, but he figured it would be easy enough to do since he had a lot of the parts on hand already. He originally started with some neon transformers and a primary/secondary pair he used in a previous Tesla coil build, but when things were fully assembled he wasn’t completely happy with the results.

He returned to the drawing board, winding a new primary/secondary coil pair, which performed much better. The rest of the coil was pieced together with random parts he procured at IKEA along with other items he had sitting around.

He donned a mad scientist’s outfit, and with a large set of grounded tongs acting as a Faraday cage he proceeded to electrocute trick or treaters’ candy with his Tesla coil, much to the delight of the neighborhood children.

Be sure to swing by his page to see more construction details, and for a sneak peek at the candy zapping process, check out the video below.

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CadSoft’s EAGLE 6 Hits Beta And Packs Goodies

November 5, 2011 by Mike Szczys 27 Comments

Version 6 of the popular schematic and PCB layout software EAGLE is now in beta testing. The most notable change is the migration to XML file formats that we looked at last month.

[PT] didn’t waste any time getting his hands on the software and giving it a thorough test drive. The image seen above shows the files of a MintyBoost. It’s impossible to make out at this resolution, but it is indeed spitting out human-readable (well maybe) XML in the windows below instead of the ‘no trespassing’ binaries they used to use.

Earlier today when working on a feature we had to jump on a different computer that had EAGLE installed in order to look at a .SCH file. We wonder if someone will put out a rendering package that can parse the new format and spit out a quick PNG? At the very least, we expect to see some useful hacks for part replacement or pin swapping. It shouldn’t be too hard to poke around and figure out what happens when changing some of the stored values. Got anything in mind that you can do by editing these by hand?

Oh, we almost forgot! The biggest benefit you get from this is the increased version control compatiblity since programs like git will be able to perform diff functions on the files.

Urine Territory Marking, Now For Humans!

November 2, 2011 by Jeremy Cook 14 Comments

Although Dogs and other animals love to mark their territory with urine, this technique has been generally ignored by human beings. Despair no more, fellow homo sapiens, we have now developed the ability to check-in on foursquare through your information stream. This device is descriptively called “Mark your Territory.”

Although this is not currently available to buy in stores (although apparently $10,000 will get you one built), [Instructables] user [blorgggggg] has furnished directions on building your own. The system is powered by an Arduino and an Android phone. The urine tags have both a pointed end for sticking in grass and the like, and a sticky back to be used in a “more urban settings.”

The video after the break gives quite a bit of background trying to justify such a system in terms of communicating in the physical world, animals, et cetera, but it’s doubtful that this excuse will get you out of a public urination charge. You’ve been warned.

[youtube http://www.youtube.com/watch?v=rRdfeb7vDWg&w=470&h=315%5D

Ants Duke It Out In The AI Challenge

October 28, 2011 by Mike Szczys 19 Comments

All of those orange, cyan, and yellow dots represent digital ants fighting for supremacy. This is a match to see who’s AI code is better in the Google backed programming competition: The AI Challenge. Before you go on to the next story, take a hard look at giving this a try for yourself. It’s set up as a way to get more people interested in AI programming, and they claim you can be up and running in just five minutes.

Possibly the best part of the AI Challenge is the resources they provide. The starter kits offer example code as a jumping off point in 22 different programming languages. And a quick start tutorial will help to get you thinking about the main components involved with Artificial Intelligence coding.

The game consists of ant hills for each team, water as an obstacle, and food collection as a goal. The winner is determined by who destroyed more enemy ant hills, and gathered more resources. It provides some interesting challenges, like how to search for food and enemy ant hills, how to plot a path from one point to another, etc. But if you’re interested in video game programming or robotics, the skills you learn in the process will be of great help later in your hacking exploits.