high voltage

243 Articles

Digital prototype of Zeusfilter 1.0

How To Stop Zeus From Toasting Your Pi

August 22, 2025 by 18 Comments

If you’ve ever lost gear to lightning or power spikes, you know what a pain they are. Out in rural Arkansas, where [vinthewrench] lives, the grid is more chaos than comfort – especially when storms hit. So, he dug into the problem after watching a cheap AC-DC module quite literally melt down. The full story, as always, begins with the power company’s helpful reclosers: lightning-induced surges, and grid switching transients. The result though: toasted boards, shorted transformers, and one very dead Raspberry Pi. [vinthewrench] wrote it all up – with decent warnings ahead. Take heed and don’t venture into things that could put your life in danger.

Back to the story. Standard surge suppressors? Forget it. Metal-oxide varistor (MOV)-based strips are fine for office laptops, but rural storms laugh at their 600 J limits. While effective and commonly used, MOVs are “self-sacrificing” and degrade over time with each surge event.

[vinthewrench] wanted something sturdier. Enter ZeusFilter 1.0 – a line-voltage filter stitched together from real parts: a slow-blow fuse, inrush-limiting thermistor, three-electrode gas discharge tube for lightning-class hits, beefy MOVs for mid-sized spikes, common-mode choke to kill EMI chatter, and safety caps to bleed off what’s left. Grounding done right, of course. The whole thing lives on a single-layer PCB, destined to sit upstream of a hardened PSU.

As one of his readers pointed out, though, spikes don’t always stop at the input. Sudden cut-offs on the primary can still throw nasty pulses into the secondary, especially with bargain-bin transformers and ‘mystery’ regulators. The reader reminded that counterfeit 7805s are infamous for failing short, dumping raw input into a supposedly safe 5 V rail. [vinthewrench] acknowledged this too, recalling how collapsing fields don’t just vanish politely – Lenz makes sure they kick back hard. And yes, when cheap silicon fails, it fails ugly: straight smoke-release mode.

In conclusion, we’re not particularly asking you to try this at home if you lack the proper knowledge. But if you have a high-voltage addiction, this home research is a good start to expand your knowledge of what is, in theory, possible.

330k volts

Sparks Fly: Building A 330 KV Supply From A PC PSU

August 7, 2025 by 30 Comments

If you’re hunting for a bench power supply, you’ll quickly notice options dry up above 48 V or so, and you definitely won’t find a 330 kV supply on the shelf at your local electronics shop. But with just a few parts, [Mircemk] has crafted a high-voltage source from a modified PC power supply that delivers electrifying results.

The sparks arcing over a foot of thin air are a dead giveaway, but let’s be clear: this project is not for beginners. High voltage — defined as around 1,000 V and up, with this project hitting 350 times that — carries risks of severe injury or death. Only tackle it if you fully understand the dangers and take precautions like proper insulation and never working alone.

This project showcases a Cockcroft-Walton voltage multiplier, a clever setup using diodes and capacitors to step up voltage. The capacitors charge and discharge in an alternating pattern, doubling the voltage after each diode pair. [Mircemk] uses 3 mm thick Plexiglas as an insulator, providing both structure and electrical isolation for the diode-capacitor cascade.

To achieve the 330,000 V output, [Mircemk] starts by modifying a standard PC ATX power supply, removing the Schottky diodes from the secondary winding’s output to produce a roughly 15 V square wave. This feeds into another transformer, boosting the voltage before it enters the Cockcroft-Walton multiplier. At first glance, the multiplier’s sides look identical, but their opposite polarities create a massive potential difference across the spark gap.

[Mircemk]’s benchtop exploration into high-voltage territory is a shocking success. If this project lights up your curiosity, dive into our other high-voltage adventures, like DIY Tesla coils or plasma speakers, for more electrifying inspiration.

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Homebrew Pockels Cell Is Worth The Wait

June 25, 2025 by 11 Comments

We haven’t seen any projects from serial experimenter [Les Wright] for quite a while, and honestly, we were getting a little worried about that. Turns out we needn’t have fretted, as [Les] was deep into this exploration of the Pockels Effect, with pretty cool results.

If you’ll recall, [Les]’s last appearance on these pages concerned the automated creation of huge, perfect crystals of KDP, or potassium dihydrogen phosphate. KDP crystals have many interesting properties, but the focus here is on their ability to modulate light when an electrical charge is applied to the crystal. That’s the Pockels Effect, and while there are commercially available Pockels cells available for use mainly as optical switches, where’s the sport in buying when you can build?

As with most of [Les]’s projects, there are hacks galore here, but the hackiest is probably the homemade diamond wire saw. The fragile KDP crystals need to be cut before use, and rather than risk his beauties to a bandsaw or angle grinder, [Les] threw together a rig using a stepper motor and some cheap diamond-encrusted wire. The motor moves the diamond wire up and down while a weight forces the crystal against it on a moving sled. Brilliant!

The cut crystals are then polished before being mounted between conductive ITO glass and connected to a high-voltage supply. The video below shows the beautiful polarization changes induced by the electric field, as well as demonstrating how well the Pockels cell acts as an optical switch. It’s kind of neat to see a clear crystal completely block a laser just by flipping a switch.

Nice work, [Les], and great to have you back.

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Grid overlayed onto a mason jar. Across the grid are high voltage purple coronas.

High Voltage For Extreme Ozone

May 21, 2025 by 3 Comments

Don’t you hate it when making your DIY X-ray machine you make an uncomfortable amount of ozone gas? No? Well [Hyperspace Pirate] did, which made him come up with an interesting idea. While creating a high voltage supply for his very own X-ray machine, the high voltage corona discharge produced a very large amount of ozone. However, normally ozone is produced using lower voltage, smaller gaps, and large surface areas. Naturally, this led [Hyperspace Pirate] to investigate if a higher voltage method is effective at producing ozone.

Using a custom 150kV converter, [Hyperspace Pirate] was able to test the large gap method compared to the lower voltage method (dielectric barrier discharge). An ammonia reaction with the ozone allowed our space buccaneer to test which method was able to produce more ozone, as well as some variations of the designs.

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X-Rays From An Overdriven Magnetron

April 28, 2025 by 34 Comments

If you say that you’re “nuking” something, pretty much everyone will know that you mean you’re heating something in the microwave. It’s technically incorrect, of course, as the magnetron inside the oven emits only non-ionizing radiation, and is completely incapable of generating ionizing radiation such as X-rays. Right?

Perhaps not, as these experiments with an overdriven magnetron suggest. First off, this is really something you shouldn’t try; aside from the obvious hazards that attend any attempt to generate ionizing radiation, there are risks aplenty here. First of all, modifying magnetrons as [SciTubeHD] did here is risky thanks to the toxic beryllium they contain, and the power supply he used, which features a DIY flyback transformer we recently featured, generates potentially dangerous voltages. You’ve been warned.

For the experiment, [SciTubeHD] stripped the magnets off a magnetron and connected his 40-kV AC power supply between the filament and the metal case of the tube. We’re not completely clear to us how this creates X-rays, but it appears to do so given the distinctive glow given off by an intensifying screen harvested from an old medical X-ray film cassette. The light is faint, but there’s enough to see the shadows of metallic objects like keys and PCBs positioned between the tube and the intensifying screen.

Are there any practical applications for this? Probably not, especially considering the potential risks. But it’s still pretty cool, and we’re suitably impressed that magnetrons can be repurposed like this.

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Turning A Kombucha Bottle Into A Plasma Tube

March 21, 2025 by 8 Comments

Kombucha! It’s a delicious fermented beverage that is kind to your digestive system and often sold in glass bottles. You don’t just have to use those bottles for healthy drinks, though. As [Simranjit Singh] demonstrates, you can also use them to create your very own plasma tube.

[Simranjit’s] build begins with a nice large 1.4-liter kombucha bottle from the Synergy brand. To make the plasma tube nicely symmetrical, the bottle had its original spout cut off cleanly with a hot wire, with the end then sealed with a glass cap. Electrodes were installed in each end of the tube by carefully drilling out the glass and installing small bolts. They were sealed in place with epoxy laced with aluminium oxide in order to improve the dielectric strength and aid the performance of the chamber. A vacuum chamber was then used to evacuate air from inside the chamber. Once built, [Simranjit] tested the bottle with high voltage supplied from a flyback transformer, with long purple arcs flowing freely through the chamber.

A plasma tube may not be particularly useful beyond educational purposes, but it does look very cool. We do enjoy a nice high-voltage project around these parts, after all.

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Schematic of a circuit

Hacking Flux Paths: The Surprising Magnetic Bypass

February 21, 2025 by 6 Comments

If you think shorting a transformer’s winding means big sparks and fried wires: think again. In this educational video, titled The Magnetic Bypass, [Sam Ben-Yaakov] flips this assumption. By cleverly tweaking a reluctance-based magnetic circuit, this hack channels flux in a way that breaks the usual rules. Using a simple free leg and a switched winding, the setup ensures that shorting the output doesn’t spike the current. For anyone who is obsessed with magnetic circuits or who just loves unexpected engineering quirks, this one is worth a closer look.

So, what’s going on under the hood? The trick lies in flux redistribution. In a typical transformer, shorting an auxiliary winding invites a surge of current. Here, most of the flux detours through a lower-reluctance path: the magnetic bypass. This reduces flux in the auxiliary leg, leaving voltage and current surprisingly low. [Sam]’s simulations in LTspice back it up: 10 V in yields a modest 6 mV out when shorted. It’s like telling flux where to go, but without complex electronics. It is a potential stepping stone for safer high-voltage applications, thanks to its inherent current-limiting nature.

The original video walks through the theory, circuit equivalences, and LTspice tests. Enjoy!

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