Rebuilding A 50,000 Volt Power Supply


The theory behind building power supplies is relatively easy, but putting it into practice and building a multi-kilovolt supply is hard. A big transformer in air will simply spark to itself, turning what could be something very cool into something you just don’t want to be around. [glasslinger] over on YouTube is an expert at this sort of thing, as shown in his 50,000 Volt power supply build. That’s a 55 minute long video, and trust us: it’s worth every minute of your time.

[glasslinger] began his build by taking an old 15,000 Volt neon sign transformer and repurposing the coils and cores for his gigantic 50,000 volt transformer. There was a small problem with this little bit of recycling: the neon sign transformer was potted with tar that needed to be removed.

To de-pot the transformer, [glasslinger] made a small oven from a helium tank, melting all the goo out with an old school gasoline torch. From there, hours and hours of cleaning ensued.

The transformer cores were cleaned up and cut down, and a new primary wound. A small-scale test (shown above) using the old secondaries resulted in a proof of concept with some very large sparks. The next step was putting the entire transformer in a box and filling it with transformer oil.

The money shot for this build comes when [glasslinger] assembles his transformer, rectifier, and all the other electronics into a single, surprisingly compact unit and turns standard wall power into a 50,000 Volt spark. You can literally smell the ozone from the video.


43 thoughts on “Rebuilding A 50,000 Volt Power Supply

      1. That skirt is superb! But I am pretty sure that glasslinger’s gender is male. They call him Ron in video comments (please correct me if Ron is also a feminine name in USA, I’m not native).

    1. Gender and gender identity shouldn’t be an issue. Glasslinger posts some awesome videos (the video posted about using skate bearings for a 30,000 rpm turbo vacuum pump is badass) This is a person who has a lot of experience.

    1. Unless you’re really well grounded 120VAC isn’t too dangerous. Bare feet on a concrete floor and you have some real concerns. Wearing good shoes on a wooden floor? Probably not. Like the old electronics techs often said, work with one hand in your pocket and you’re safe.

      The worst hit I ever took I got out of an old tube amplifier when I was leaning on the metal chassis with my forearm then managed to touch something I shouldn’t have. It was hot in the summer and I was sweating too. Trust me when I say wall current has nothing on that!

      1. worse for me, was what could only be rationalised by describing it as
        an indirect shock from a lightning strike

        weirder after effects then being choked out or even hallucination

        feels like you just woke up and dreamed of a black lightning bolt on a white backround. execpt its night out and lightning is white. you cant see or hear anything for several minutes

        either lightning has a pressure-wave strong enough to knock me out for 2 seconds
        or the muscle contraction was enough to hit me against the wall hard enough

        either way i “woke up” still standing, then almost fell.

        weirdest expierence EVER.

        PS: got my max dose of gamma rays for life, lightning at close range has tons of gamma rays

      2. Yeah still scary, I’ve had some close calls; no 50kV archs, but still. Yeah, got some radios w/ some nice amps, one wrong move…Never been tasered but people swear it’s the worst.

      3. I remember reaching under an old monitor to adjust the brightness. We got it from someone who worked at the plant that makes them. To save money, or cos he’d snuck it out, or whatever, it had no case, just bare PCBs. Obviously I missed the brightness control. I dunno how many volts it was, but being just an inch gap between the monitor and the floor, I spent a good while with my hand bouncing off the floor, back to the PCB, and back again.

        Eventually somebody switched the power off.

        And since that day, I can move metal objects with my mind.

  1. Can’t they just use an auto ignition coil? Some of those are rated for high output voltage, although not quite 50,000V. 45,000V for the Accel Super Coil. I’m not sure if the low input voltage is the major limiting factor there. Car voltage systems are only 12VDC after all.

    Many years ago I fooled around with an old auto ignition coil (a regular cylindrical 12,000V one) and I was able to get a one inch spark out of it using a 9 volt battery. That was the challenge I set for myself. How long of a spark could I get using just a 9V battery? At one inch I was fairly satisfied with things too.

    Other technical challenges I did not have solutions for at the time caused me to abandon the pursuit. Mostly I didn’t know about back EMF protection diodes back then so I kept on blowing out my MOSFET drive. That started to add up costs for me at a buck and change a misfire.

  2. The video poster just ripped down and converted a neon sign transformer into a switch mode power supply using the original coils and core plates that came with the original kit to generate a continuous transformer at 50kV and you’re comparing it to some cheezy transistor driven ignition coil powered by a 9V battery which is so 3rd grade HV science project?

    HaD needs more HV projects for sure, there’s a lot of stuff out there that I think you could make a multitude of posts out of.

  3. Half the fun of reading this site is laughing at the comments when the safety nazis come crawling out of their holes, wagging their fingers. On the other hand, having worked with high voltage for years and knowing a few people who got hurt, I will simply say that the image on the top shows something I would never, ever do, which is to trust thin insulation like that. I’ve done a lot of repairs on equipment where special high voltage wire popped through because it was touching something else at a different potential. That cured me of ever trusting the insulation rating on any wire. And another thing I know; if you get nailed with high voltage it can blow through the heels of your shoes and leave the soles of your feet in them if there’s enough current behind it. Sorry for the gruesome tale, but … I stay a minimum of three feet away from anything over about 5,000 volts. And I’m not a safety nazi.

    Ignition coils for cars are meant for low duty cycle, if they get used continuously they will overheat.

    1. You always need to respect true high voltage beyond what most people would consider reasonable(and any voltage above the dangerously conductive threshold of human skin). I’m .guessing. the person in the video has plenty of experience, judging from the content and knowledge in the video. They seem to know that they can do that safely without turning into a bubbling cesspit of human remains that EMS finds when the neighbors report a ‘weird stench’, although it may be a bad example for entry level folks.

      There are plenty of videos out there about the dangers of working on high voltage circuits, and it’s well worth reviewing them if you plan to do any high voltage projects. Linesman stories can tell a lot, even though the currents on the hobbyist level are much lower, the basic effects and ‘strangeness’ of high voltage power supplies still apply. If you’re an electrical science nerd or geek and wing-suit jumping isn’t for you, HV might be the equivilant!

    2. I definitely got the heebie-jeebies from the lack of thickness on the insulation of his cables. Insulation on flexible alligator cables tends to break down, and HV likes to find its way though cracks.

      1. I suspect it’s less risk in this situation because the output isn’t ground referenced anywhere (this is explicitly mentioned somewhere in the video) so unless they have a hand on each side of the winding, there isn’t a risk of being electrocuted – it’s an isolated (isolation) transformer… but it’s not exactly the safest either… drop the lead by accident and now your other output is at +50KV to ground… and you definitely don’t want to go anywhere near that.

        That said… I cringed too at the use of what are probably 600V rated alligator clip leads to conduct said 50KV. When it comes to HV… can never be safe enough.

    3. Ignition coils for cars are meant for low duty cycle, if they get used continuously they will overheat.
      No, Ignition coils *are* continuous duty, they can be of quite a respective power too:

      You have, for example – in a typical car engine – 4 cylinders going at 4000 rpm, that needs four sparks per revolution or 16 kHz operating frequency.

      Typically, one wants to have 5 milli-Joules per spark to ignite the fuel mixture, to have some margin (1 mJ is considered the minimum). The power through the ignition coil is Joules per second so we multiply the 16000 sparks per second with the 0.005 J per spark, which gives 80 W of continuous power at 4000 rpm.

      The 80 W is fairly decent and not something one wants to put ones mitts on! With a bit of careful coil characterisation and clever converter design – one could probably get 200 W or so through an ignition coil.

      1. Nah…. As far as I recall the m in rpm is *minute*, which means that your figures are 60 times too high. So the operating frequency would be a tad over 1 kHz. And that would bring the quite impressive 80 watt down to a measly 1.3 watt.

      2. Cars are 4 stroke motors, so 2 sparks per revolution. 4000 revs per minute is 66 2/3 revs per second. 2 sparks per rev comes to 133 1/3 Hz. Also consider how much time do cars usually spend at 4K rpm?

        Some cars (like early 90s GMs with the 3.3 and 3.8L V6) run coils that run 2 cylinders timed 180 degrees apart in the firing cycle, so they do fire every rev. But then again they only fire 1/3 as often as a single coil / distributor setup would on a v6.

    1. No typo…. 50kA at 0.5V shorted output. 0-240V ac input. Vid is running at about 35kA as he doesn’t have enough capacity at home for full rated output. Also needs to increase the size of the buss bars as they get rather warm… Secondaries are 40mm (~1.5″) diameter copper cable x 3. As shown running in the vid, drawing about 45A from the mains.

  4. instead of rebuilding you could use diode capacitor network multiplier.

    the crt tv uses multiplier.

    older tvs had the flyback transformer and multiplier as separate blocks

    modern crt tvs have the transformer and multiplier built into 1 unit.

    as of the gender thing it is a he he was probably born with ais a condition that somewhere in development the body became resistant to a substance causing incomplete gender conversion.

    using a cutting torch on freon tanks you want to be careful since especially cfc based freons they can decompose and make poisonous gas and even though the tank is empty there may still be traces left so be careful and do the cutting outdoors

    1. Except that a diode capacitor multiplier cannot provide any real current without gigantic parts, and will blow immediately if you short it out! Making small very short arcs and powering lifters are nothing compared to some of the things you can do or would need a supply like was built above to do. The guy that built this has tons of experience. Just take a look at some of his other videos. The guy makes his own vacuum tubes and stuff, so he definitely has some experience! This project is not something just anybody should attempt to build. This thing COULD KILL YOU INSTANTLY if you are not careful! That said, this is a really cool project, and I agree with the above posters: I would love to see more HV projects here. My concern is that we will have a reduction in all the Arduino projects because the Arduino enthusiasts will try to make HV power supplies and end up killing themselves!

  5. fire and paint thinner that’s just asking for trouble you just got finished saying never cut open a propane tank but having other highly flammable stuff is not good

  6. What’s amazing to me about this video are all the tips and tricks the guy has to offer. If it weren’t for Internet => HaD => youtube => cheap video cameras, we would not be able to learn from this guy. The knowledge would just be lost.

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