That Sucks! Death of a Tesla Coil

[Electroboom] always has some entertaining videos. He recently tried to run his Tesla coil in a vacuum. The video shows some interesting results, along with his usual bleeped out expletives as he drills into his hand and suffers other indignities in the name of electronics.

Unfortunately, a bit of extra bolt caused the coil to arc internally, eventually leading to the impressive device shuffling off its mortal… um, well, let’s just say its untimely demise. Along the way, though, you get to see some interesting techniques for building a silicone seal for the vacuum chamber, and some neat Tesla coil tricks with a closed off syringe.

We were a little concerned for [Electroboom’s] safety when he calculated the force on his bell jar was about 6,000 pounds. After all, he’s not known for a stellar safety record. However, he surmised that the symmetry of the jar caused most of the force to cancel out. He even tested the theory. Still, if you try this, be sure to be careful. He could have probably stood at least eye protection, just in case.

[Electroboom] isn’t the first person to have put a coil in a vacuum chamber, but he may be the most humorously injured person to attempt it. If the high input voltages worry you, perhaps you can try this variation. Or, if you don’t want to build such a large vacuum chamber, you could do always get small or even go solid state, for the best of both worlds. On the other hand, if you have a coil, there’s a lot of fun you can have with them, without melting it down in a vacuum.

17 thoughts on “That Sucks! Death of a Tesla Coil

  1. You’re getting leaks through the insulation of the wires. Replace the wires with two brass binding posts sealed with silicon in the holes they go through. That way no air can link in through the metal posts.

    1. You can see in the video from 4:16 – 4:50 that he drilled holes through the bottom plate of the vacuum tower and did not seal the holes properly (did not use enough sealant).

      I think he lost more air through these holes than through the insulation of the wires.

  2. Proof that drinking maple syrup causes people to develop a sense of humour. My kids really like his videos, fortunately the younger ones don’t get half his jokes. It is like watching Shrek with the whole family, he operates at different levels, like an onion. Come to think about it if he wasn’t as hairy and was green he’d be a lot like Shrek.

      1. Kind of. The mean free path of electrons is actually alarmingly large in even moderate vacuums, so a large amount of electrons will strike a ground without hitting any air, even if some of them ionize it. I don’t have the actual numbers (can’t find them) but it is surprising what you can achieve with a refrigeration vacuum pump

        1. Firstly, glass is opaque to UV so there’s no danger from that.

          Next, the absorption coefficient of glass and 10″ of air (outside the chamber) is so large at the energies he’s working with that virtually no X-rays get past. He’s probably getting around 10KV or less. See here:

          http://henke.lbl.gov/optical_constants/atten2.html

          Finally, take the total power he’s dissipating and assume 100% conversion to X-rays, then divide by the area of his chamber to determine the irradiance (photon density) he gets… and it’s quite minimal. Goes inversely with the square of distance.

          Conversion from electron braking to X-rays is wildly inefficient, which is why X-ray tubes get very hot.

          He’s getting so few X-rays that it’s probably unmeasurable. Quite probably less than the background radiation of wherever he lives.

          (And regarding the mean free path: take the dV/dX of his tesla coil spark, perhaps 5,000 V/cm, and multiply by the mean free path, and determine how much acceleration the electron gets in that small path. It’s tiny, much less than the 10KV used in the calculation above.)

          I’m a big fan of safety in projects, but rather than hear about dangers, it’s much better to read up on dangers so that one can characterize them, and determine where the dangers actually are.

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