If you happen to be driving round the back roads of Oakland late at night—and no, we’re not going to ask why—you might happen upon an unlikely sight: a kindly-looking old gentleman standing next to a 17-foot-high Tesla coil. If so, don’t fret: that’s just nice Greg Leyh, aka Lightning on Demand, testing his terrifying lightning machine again.
Leyh is something of a legend in the outer limits of electrical experimentation. He’s cited as an inspiration by Styropyro, whose own reality-threatening experiments we covered recently, and while you’d never know it to look at him, he has a long history of building some of the world’s most insane devices. Leyh’s backstory includes a long involvement with the frankly batshit San Francisco-based performance art collective Survival Research Laboratories, whose unhinged happenings are today the stuff of legend: imagine a sort of meeting place between Throbbing Gristle and BattleBots, staged in a bleak liminal space under a freeway with an apparent lack of regard for safety and/or sanity.
Watching SRL events today is a window into a completely different city and a completely different time, when a bunch of nutters could do things like construct a replica V-1 rocket that generated 300 calls to the city’s earthquake hotline or unleash a six-legged robot walker controlled by someone’s pet guinea pig. One suspects that today’s San Francisco would be rather less receptive to such activities, and indeed, SRL seems to be largely dormant today.
Leyh hasn’t been idle, though. A year or so ago he unveiled an upgraded version of a device he calls the Lorentz plasma cannon, and this month he returned with an update on another long-term project: a colossal Tesla coil. As he explains, he began building the device in 1990 with parts from an Oakland scrapyard, and on its completion, it was the largest operating Tesla coil in the world. It was put to work at SRL shows, often to disable “hostile machines” by cooking their on-board electronics.
As Leyh explains it, the upgrades made since have focused largely on boosting the output current that can be sent along its output arcs. “Tesla coils can produce fantastically high voltages,” he explains, “but … low output currents.” Boosting these currents involves synchronizing a large boost in the device’s primary with the moment its arc touches its target. This creates a channel of conductive plasma through which perilous amounts of current can be discharged.
Of course, doing this isn’t straightforward. Boosting the energy requires the use of something called a “pulse forming network,” which—as its name suggests—creates a brief spike of high current. The challenge is timing this pulse correctly so that it passes through the coil and out via the arc, rather than into the coil’s components. “This last part,” Leyh notes drily, “is especially important if we want to perform the experiment more than once.”
Leyh’s Atacama-dry delivery is a highlight of his videos, and he’s in fine form here. The pulse network/plasma channel combination works a treat, and he demonstrates the difference between the effects of a boosted pulse and the unboosted arc of a normal Tesla coil by one of each at an incandescent light tube. The unboosted arc makes the tube glow. As he prepares the boosted pulse, Leyh explains “the tube should become noticeably brighter.” The tube duly detonates.
A few minutes later, another terrifying arc is sent at one of the small buildings Leyh has built to demonstrate the potential effects on an unshielded structure. Those effects turn out to be “a loss of structural integrity,” which is certainly one way of saying that the building is basically obliterated.
The pièce de resistance, however, comes at the end of the video, when Leyh unleashes the coil’s full output power onto a hapless Ford Econoline van. The discharge completely liquefies the car’s electronics, reducing every piece of wiring within to bubbling pools of copper. Or, as Leyh puts it: “It appears that the [car’s] electronics … were adversely affected by the boosted energy pulse.”
The video closes with Leyh explaining that while the machine currently has a working range of about 30 feet, an effect called “relativistic runaway breakdown” could “dramatically boost the strike range by a factor of 10 or more”. It may also open a portal to the netherworld, but those are the risks you take at the outer reaches of science. Godspeed, kind sir.
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