01-05-11 – Sparks, Arcs, and Other Flashy Things

I see what you did there

Or, you could build a Jacob’s Ladder
http://www.ee.washington.edu/circuit_archive/circuits/jacobs.html

I attempted it, but I couldn’t generate enough voltage with transformers on hand. I had two MOTs with the primaries wired in parallel, and the secondaries wired in series for 4000VAC total, but just could draw a spark. I had the electrodes less than 1mm apart, and had a starting electrode in the middle and still no joy. I honestly felt that I couldn’t get them any closer without shorting.

So I went and got creative with a flash-cap about four hours before the contest.

Kat and Kestrana – you might want to get some life insurance on the spouses.

/electricity scares me.
//because I don’t understand it
///so I should, indeed, be scared.

Or, you could build a Jacob’s Ladder
http://www.ee.washington.edu/circuit_archive/circuits/jacobs.html

I attempted it, but I couldn’t generate enough voltage with transformers on hand. I had two MOTs with the primaries wired in parallel, and the secondaries wired in series for 4000VAC total, but just could draw a spark. I had the electrodes less than 1mm apart, and had a starting electrode in the middle and still no joy. I honestly felt that I couldn’t get them any closer without shorting.

So I went and got creative with a flash-cap about four hours before the contest.

I’d decided not to post this story since it’s third hand. That way the person who made the device I’m about to describe could announce it on his own if he wanted. But since you all mentioned (and commented on) Jacob’s Ladders explicitly I had to mention it! This astounded and scared the hell out of me when I heard it…

A coworker who is an electrical engineer with LOTS of experience building strange contraptions is also a photographer. He hasn’t started submitting to our contests yet, but he does check them out and vote most weeks. I occasionally tell him about upcoming contests that I think might be intriguing enough that he’ll enter and the “sparks” contest was one of them. He’d told me about building a Jacob’s Ladder before and how he’d “improved” on the design a couple of times to get brighter and more dramatic electrical displays. The last one I heard about was driven by a car battery and was so powerful he thought it was generating a plasma field, not just a cute little arc of lightning. Cut to this contest… He wanted it to be brighter to make photographing if easier so he added a second car battery. The test of that device was the story that made my jaw drop. He’d used the beefiest MOTS he could find online so he was confident they could handle the power and rods were upgraded a few iterations ago so they seemed fine too. And it all did work and apparently it was spectacular. The display was unbelievably bright but there was so much power that small bits of metal were flaking off the rods creating glowing sparks that fell onto floor. And about 30 seconds into the run the device shutdown when the MOTS overheated and literally blew the tops off the chips. So no photos made it to the contest (since that was the test run). But apparently the exploded chips look interesting under a microscope so I might get to see the aftermath at least.

Or, combine your love of lethal voltage and music and build your own plasma speaker.

from your link: A GDT is simple to make, all you do is take a bundle of 3 wires and wrap them around a ferrite toroid.

having no idea what a ferrite toroid is leaves me out.

U-Man electricity is only scary because you can’t see it. a little common sense and good work habits and working with it is fine.

A ferrite toroid is basically just an iron donut.

That’s exactly how I was going to describe it.

A ferrite toroid is basically just an iron donut. It’s sometimes used for noise suppression on cables (it’s that big lump you see on the ends) and is also used in inductors.

In the picture on that page, it’s the black donut-shaped thing with the blue-and-white wires wrapped around it on the bottom left of the board.

thanks. i knew it was iron something due to the ferrite part but electronics aren’t my strong suit. want your house or business wired, fine. want your electronics fixed, not so much. had to replace a potentiometer on a machine at work a while back. figuring out where in the display circuit the problem was required both the seller’s rep and the factory rep. once i knew where the problem was i got a new one online and installed it. fortunately for me most of the machines i work on have mechanical problems not electronic. if it’s electronic i can usually get to the general area where the problem is and find someone to confirm that and walk me through the repair.

of course if i had been smarter years ago i’d be home instead of still working two days a week.