Rebuilding A 50,000 Volt Power Supply

Spark

The theory behind building power supplies is relatively easy, but putting it into practice and building a multi-kilovolt supply is hard. A big transformer in air will simply spark to itself, turning what could be something very cool into something you just don’t want to be around. [glasslinger] over on YouTube is an expert at this sort of thing, as shown in his 50,000 Volt power supply build. That’s a 55 minute long video, and trust us: it’s worth every minute of your time.

[glasslinger] began his build by taking an old 15,000 Volt neon sign transformer and repurposing the coils and cores for his gigantic 50,000 volt transformer. There was a small problem with this little bit of recycling: the neon sign transformer was potted with tar that needed to be removed.

To de-pot the transformer, [glasslinger] made a small oven from a helium tank, melting all the goo out with an old school gasoline torch. From there, hours and hours of cleaning ensued.

The transformer cores were cleaned up and cut down, and a new primary wound. A small-scale test (shown above) using the old secondaries resulted in a proof of concept with some very large sparks. The next step was putting the entire transformer in a box and filling it with transformer oil.

The money shot for this build comes when [glasslinger] assembles his transformer, rectifier, and all the other electronics into a single, surprisingly compact unit and turns standard wall power into a 50,000 Volt spark. You can literally smell the ozone from the video.

 

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Soft Robotics, Silicone Rubber, And Amazing Castings

Most of the robotics projects we see around here are heavy, metallic machines that move with exacting precision with steppers, servos, motors, and electronics. [Matthew] is another breed of roboticist, and created a quadruped robot with no hard moving parts.

[Matthew] calls his creation the Glaucus, after the blue sea slug Glaucus atlanticus. Inside this silicone rubber blob are a series of voids, allowing compressed air to expand the legs, gently inching Glaucus across a table under manual or automatic control.

Even though no one seems to do it, making a few molds for casting on a 3D printer is actually pretty easy. [Matthew] is taking this technique to an extreme, though: First, a mold for the interior pressure bladders are printed, then a positive of this print made in silicone rubber. These silicone molds – four of them, for the left, right, top and bottom – are then filled with wax, and the wax parts reassembled inside the final ‘body’ mold. It’s an amazing amount of work to make just one of these soft robots, but once the molds and masters are made, [Matthew] can pop out a soft robot every few hours or so.

There’s a lot more info on Glaucus over on the official site for the build, and a somewhat simpler ‘compressed air and silicone rubber’ tentacle [Matthew] built showing off the mechanics. Video below.

 

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The Gathering: Shanghai’s Hackaday Community

Screen Shot 2014-03-23 at 12.33.00 AMIt happened! The Gathering crossed the Pacific and landed in Shanghai on Thursday, March 20th. It took place at the venue ironically called ‘Abbey Road’ (it’s the only one we could find on such a short notice) and more than 150 people showed up. The whole scene had a huge Chatsubo feel too it – an eclectic mix of local and expat hackers and engineers, professors, students and all sorts of industry mercenaries from around the world. And everyone with skull-and-wrenches t-shirt or a sticker on.

I can only imagine what Chinese police would think if they happened to drop by. Not to mention if they asked how in the world did all these ‘anarchist’ t-shirts enter the country.

But that’s another story…

We met a lot of exciting people and heard all sorts of weird tales, such as the (off-the-record) one about the real reasons behind certain well-known laptop manufacturer’s batteries bursting into flames. We also got a lot of great advice on smuggling electronic components out of China and other everyday tips & tricks.

d8d27574b02a11e38f1d121190b145cb_8My favorite conversation was with [Alexander Klink] on his research in Denial of Service attacks using algorithmic complexity of collision resolution in (a priori known) hash functions. Though the original paper is more than two years old, its takeaways can still have a huge impact on all sorts of software and hardware devices out there.

The general theme of the night was how exciting it is to live in a place like Shanghai, where rapid urban growth and access to manufacturing resources meets a blossoming technology and art scene. It is even more so thanks to places like Xin Che Jian, which make being a “hacker” a socially acceptable thing on the other side of the Great Firewall.

That said, reading all of Hackaday content still requires a proxy.

3 Cheap Hood/Hatchback/Topper Mods To Save Your Noggin

Gas Lift Fixes by Briansmobile1

This is a mod more than a hack but any time you can alter original equipment to maintain its usability is a win-win scenario for you and the environment. Everyone has or knows somebody that has a vehicle and most vehicles nowadays have some type of hatchback or hood where the support solution is gas filled struts. Inevitably these gas filled struts fail with age and the failure is accelerated in hotter or colder climates. If you ever had to replace these items you know they can cost a minimum of $20 to as much as $60 a piece. Most vehicles require two, four or even eight of these costly little devices.

[Brian] from Briansmobile1 YouTube channel documented three simple and low cost solutions. We all probably know of the vice clamp solution but that is cumbersome and still an expensive solution which is not always very handy or fast. Another solution is to cut a piece of rubber hose in a kind of special way so it is easy to put on and take off the shaft and dangles from a string so it’s always available. The best solution was to use a hitch pin also connected to a string or wire. To make the hitch pin work you have to grind a couple of notches on either side of the lift shaft at just the right spot so the pin can be snapped on and prevent the shaft from retracting at your selected height.

We are sure these solutions will come in handy at some time in most everyone’s driving career. Just after the break we will link to all three of [Brian’s] handy videos on gas strut fix solutions. And if you do your own automotive repair we can definitely recommend [Brian’s] channel of over 600 vehicle repair and maintenance videos which normally come with a dose of philosophy and humor.

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Embeded Sieve Of Eratosthenes: Hunting Primes On ARM

Embeded Sieve of Eratosthenes

I ended up with just enough time over the weekend to pull together a quick project. I implemented the Sieve-of-Eratosthenes on an ARM chip.

If you haven’t heard of the Sieve of Eratosthenes then you really need to work your way through Project Euler. That’s where I first learned about this method of finding prime numbers. You begin with a list of all numbers, find a prime, then remove all multiples of that prime from the list. The real trick with doing it on a microcontroller is to figure out how to store a large list of numbers in a limited space. The gist of my method was to use a boolean array (I call it a bit-packed array but that may be the wrong way of saying it). The details are found in my project linked at the top.

‘Why?’ is almost always the wrong question to ask around here. But in this case, I did this because I wanted to try out the Bit Banding functionality of the ARM core. These chips have alias addresses that map to a single bit in the SRAM and also some of the peripheral registers. This allows read or write access for a single bit using a single instruction. Turns out that one side effect of 32-bit architecture is having addresses to burn.

Mechanical Iris Will Make You Want A Laser Cutter Even More

Mechanical irises are very intricately designed mechanisms that are mesmerizing to see in action — and if you have a laser cutter, you could make one in less than 10 minutes.

Our “Teacher of Science”, Instructables’ user [NTT] has revised a previous Instructables design on a mechanical iris to improve it. The original design used three layers of components and dowel pins for every joint. What [NTT] has done is reduced this to two layers, and eliminated half of the pins required by designing clever circular cutouts. The result is a very slick mechanical iris that is very easy and quick to build — provided you have the tools.

Stick around to see the original iris open and close — unfortunately there’s no video of the new design — but we think you can imagine the differences.

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Monitoring Your Gas Consumption With A JeeNode And A NRF24L01+

[Sven337] just blogged about a gas consumption monitoring setup he finished not long ago. As his gas meter was located outside his apartment and nowhere near any electrical outlet, a battery-powered platform that could wirelessly send the current consumption data to his Raspberry Pi was required. His final solution therefore consists of a JeeNode coupled with the well known nRF24L01+ wireless transmitter, powered by 3 supposedly dead alkaline batteries.

[Sven337] carefully looked at the different techniques available to read the data from his meter. At first he had thought of using a reflective sensor to detect the number 6 which (in France at least) is designed to reflect light very well. He then finally settled for a magnetic based solution, as the Actaris G4 gas meter has a small depression intended for magnetic sensors. The PCB you see in the picture above therefore has a reed sensor and a debug LED. The four wires go to a plastic enclosure containing the JeeNode, a couple of LEDs and a reset switch. Using another nRF24L01, the Raspberry Pi finally receives the pulse count and reports it to an eeePC which takes care of the storage and graphing.