Is That An EMP Generator In Your Pocket Or Is My Calculator Just Broken?

June 17, 2021 by Dan Maloney 39 Comments

Ah, what fond memories we have of our misspent youth, walking around with a 9,000-volt electromagnetic pulse generator in our Levi’s 501s and zapping all the electronic devices nobody yet carried with them everywhere they went. Crazy days indeed.

We’re sure that’s not at all what [Rostislav Persion] had in mind when designing his portable EMP generator; given the different topologies and the careful measurement of results, we suspect his interest is strictly academic. There are three different designs presented, all centering around a battery-powered high-voltage power module, the Amazon listing of which optimistically lists as capable of a 400,000- to 700,000-volt output. Sadly, [Rostislav]’s unit was capable of a mere 9,000 volts, which luckily was enough to get some results.

Coupled to a spark gap, one of seven different coils — from one to 40 turns — and plus or minus some high-voltage capacitors in series or parallel, he tested each configuration’s ability to interfere with a simple pocket calculator. The best range for a reset and scramble of the calculator was only about 3″ (7.6 cm), although an LED hooked to a second coil could detect the EMP up to 16″ (41 cm) away. [Rostislav]’s finished EMP generators were housed in a number of different enclosures, one of which totally doesn’t resemble a pipe bomb and whose “RF Hazard” labels are sure not to arouse suspicions when brandished in public.

We suppose these experiments lay to rest the Hollywood hype about EMP generators, but then again, their range is pretty limited. You might want to rethink your bank heist plans if they center around one of these designs.

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Subaru Coils Make A Great HV Power Source

September 14, 2019 by Lewin Day 28 Comments

High-voltage experimenters are a unique breed. They’re particularly adept at scrounging for parts in all kinds of places, and identifying how to put all manner of components to use in the service of the almighty arc. [Jay] is one such inventor, and recently came across a useful device from Subaru.

The device in question is an ignition coil from the Subaru Outback. It consists of a pair of high-voltage transformers, connected together, in a wasted-spark setup to run four-cylinder engines. Having sourced the part from a friend, [Jay] realised that with some modification, it would make a great high-voltage power source. The first job was to figure out how to remove the internal electronics that drive the transformers. In this case, it was a simple job of hacking off a chunk of the case, removing the interfering hardware. With this done, it’s possible to directly access the transformer connections.

In [Jay]’s experiments, the device is run in an anti-parallel configuration, to produce higher than normal voltages at the output. In various tests, it’s demonstrated running from both a classic 555 circuit, as well as a ZVS driver. For future projects, [Jay] intends to use this setup to drive a large voltage multiplier, also noting it can be used with Tesla coils and plasma balls with the right additional hardware.

While [Jay] doesn’t include any specific model numbers, reports are that these coils are readily available in a variety of 1990s and 2000s Subaru vehicles. Others have used similar hardware to create high voltage projects, too – this stun gun is a great example. Video after the break.

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Perf Board Pyrotechnics Courtesy Of A High-Voltage Supply

August 26, 2018 by Dan Maloney 21 Comments

You may have asked yourself at one time or another, “Self, what happens when you pass 100 thousand volts through a printed circuit board?” It’s a good question, and [styropyro] put together this fascinating bit of destructive testing to find out.

Luckily, [styropyro] is well-positioned to explore the high-voltage realm. His YouTube stock-in-trade is lasers, ranging from a ridiculously overpowered diode-laser bazooka to a bottle-busting ruby laser. The latter requires high voltage, of course, and his Frankenstein’s lab yielded the necessary components for this destructive diversion. A chopper drives dual automotive ignition coils to step the voltage up to a respectable 100 kV. The arcs across an air gap are impressive enough, but when applied to a big piece of copper-clad protoboard, the light show is amazing. The arcs take a seemingly different path across the board for each discharge, lighting up the path with an eerie blue glow accompanied by a menacing buzz. Each discharge path may be random, but they all are composed of long stretches across the rows and columns of copper pads that never take the more direct diagonal path. [styropyro]’s explanation of the math governing this behavior is feasible, but really we just liked looking at the pretty and dangerous display. Now if only the board had been populated with components…

No, there’s not much of a hack here, but it’s cool nonetheless. And it’s probably a well-earned distraction from his more serious stuff, like his recent thorough debunking of the “Chinese laser rifle” that was all over the news a while back.

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Arduino Nixie Shield

June 22, 2009 by Zach Banks 8 Comments

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Reader [Bradley] sent in his ArduiNIX project, an Arduino shield designed for driving nixie tubes. The shield allows the Arduino to drive and multiplex nixie tubes without any additional hardware. These antique-looking displays are commonly hacked into clocks. It takes 9 volts from a wall wart and steps it up to over 200V in order to drive the displays. The shield is capable of multiplexing up to 80 individual elements. He has example code for driving a 6-digit display and a clock on his site. He is selling kits and completed shields too.

Related: Victorian nixie tube clock

[thanks Bradley!]

High Voltage Cable Inspection

January 14, 2009 by Strom Carlson 27 Comments

high-voltage-woker

Have you ever wondered how they inspect high voltage cables without taking them out of service? Check out this video which offers a glimpse into the life of a professional high voltage cable inspector. There are parts of the job you’d expect—namely perching on the cable like a bird, trying to not fall off—but the part of the job you wouldn’t expect is the suit. This suit is made of 75% Nomex, to prevent it from catching fire, and 25% stainless steel thread, turning the suit into a wearable Faraday cage. Of course, because he’s got a Faraday cage mere millimeters from his skin, the cable inspector spends his workday surrounded by half a million volts. To avoid electric shock, he equalizes the voltage potential between himself and the line before touching the cable.

Depending on your specific phobias, this video might make your job seem really dull… or really really safe.

[via Gizmodo]

Easy High Voltage Power Supply

November 10, 2008 by Eliot 16 Comments

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[rocketman221] wrote up one of the simplest ways to build a high voltage power supply. This one in particular was used on his coilgun. Instead of building a custom circuit, he’s using flash charging boards from disposable cameras. Six 450V 470uF caps are wired in parallel to make up the bank. Two of the charger boards are wired to one switch to initiate the charging process. Four additional boards are wired two a second switch for the second charging stage. The part cost on this is incredibly cheap and it only requires a 3.3V input to reach 450V. The writeup has plenty of warnings about the dangers of high voltage; you need to clean off all flux residue to prevent arcing across the circuit boards. Embedded below is a video of the bank being discharged through several objects. Continue reading “Easy High Voltage Power Supply” →