A Head-mounted Tesla Coil – What Could Possibly Go Wrong?

November 18, 2011 by Mike Nathan 26 Comments

We can hear the commercial now…

“Reeeeeeal men of geniuuuuuuus! Here’s to you Mr. no-fear, singing Tesla coil on your hat wearing guy…”

Call him a genius or call him crazy – all we know is that [Tyler’s] Tesla coil hat is awesome! Even though it’s the middle of November, we couldn’t pass up this Halloween costume.

[Tyler’s] creation essentially boiled down to taking a standard dual resonant solid state Tesla coil and shrinking it down to a reasonable size for mounting on his skull. The mini Tesla features a pretty compact boost core which worked reasonably well, at least for a little while. He says that the boost never truly worked properly and needs a redesign, which is something he’ll tackle when he gets some free time.

Boost issues or not, we think that the video below speaks for itself. The hat is certainly an attention getter, and we think it’s great – even if wearing a Tesla coil on your head is not necessarily the safest thing to do.

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This Animatronic Horus Guard Mask Is So Good, Even Anubis Would Be Fooled

November 17, 2011 by Mike Nathan 32 Comments

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[Jerome Kelty] is a big fan of the movie Stargate, and when he saw it for the first time, he wanted one of the awesome helmets worn by the Horus Guards. This isn’t the kind of thing you would normally find at your local costume shop, so he knew that he would have to build one of his own. After rejecting multiple designs over the years, he finally came up with a solution that he thought would work well.

His Horus Guard helmet was constructed primarily out of cardstock, papier-mâché, spray foam, and spackle. Don’t let that list of materials give you the wrong idea about this helmet however – it looks absolutely amazing!

Not only does it look good, but it moves just like the guard’s helmets in the movie too. To control the helmet’s movements [Jerome] used an Arduino animatronics setup he designed, which we’ve seen before in his slick Predator build from last year. The Arduino controls a set of 5 servos, which are tasked with turning the helmet’s head and actuating the fans mounted on either side.

Stick around to see a short video of the mask in action, and if you’re thinking of building one yourself, be sure to check out his writeup for a very thorough BoM.

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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.