Making Wire Explode With 4,000 Joules Of Energy

January 21, 2025 by Maya Posch 80 Comments

The piece of copper wire moments before getting vaporized by 4,000 joules. (Credit: Hyperspace Pirate, Youtube)

In lieu of high-explosives, an exploding wire circuit can make for an interesting substitute. As [Hyperspace Pirate] demonstrates in a recent video, the act of pumping a lot of current very fast through a thin piece of metal can make for a rather violent detonation. The basic idea is that by having the metal wire (or equivalent) being subjected to a sufficiently large amount of power, it will not just burn through, but effectively vaporize, creating a very localized stream of plasma for the current to keep travelling through and create a major shockwave in the process.

This makes the exploding wire method (EWM) an ideal circuit for any application where you need to have a very fast, very precise generating of plasma and an easy to synchronize detonation. EWM was first demonstrated in the 18th century in the Netherlands by [Martin van Marum]. These days it finds use for creating metal nanoparticles, brief momentary light sources and detonators in explosives, including for nuclear (implosion type) weapons.

While it sounds easy enough to just strap a honkin’ big battery of capacitors to a switch and a piece of wire, [Hyperspace Pirate]’s video demonstrates that it’s a bit more involved than that. Switching so much current at high voltages ended up destroying a solid-state (SCR) switch, and factors like resistance and capacitance can turn an exploding wire into merely a heated one that breaks before any plasma or arcing can take place, or waste a lot of potential energy.

As for whether it’s ‘try at home’ safe, note that he had to move to an abandoned industrial site due to the noise levels, and the resulting machine he cobbled together involves a lot of high-voltage wiring. Hearing protection and extreme caution are more than warranted.

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An Explosive Look At Detonators

October 20, 2023 by Al Williams 17 Comments

If you’ve ever watched a cartoon where something blows up, you’ve probably seen a detonator — the device with a plunger that, when you push it, some dynamite blows up a bridge or a building or whatever. Detonators may be common in cartoons, but they are very real, and [Our Own Device] talks about some vintage detonators and, along the way, gives a brief history of explosive compounds.

For many years, black powder — a low explosive — was the only game in town. But a flurry of scientific advances brought a new class of high explosives far more powerful than gunpowder. The story of antique explosive factory safety measures, and lack thereof, is also an interesting side detour.

We enjoyed the trip down memory lane. However, if you want to skip the history lesson, jump about 17 minutes in to get a better look at the hardware. The teardown follows soon thereafter. These boxes are built solidly and have many safety features to prevent accidental detonations. One is a dynamo device with some clever mechanisms to ensure that the unit produces enough voltage, the other uses a charged capacitor.

Our usual interest in pyrotechnics is usually aimed more at fireworks. You think of explosives as having an imprecise effect, but that isn’t necessarily the case.

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