Jacob's Ladder

Ok now that’s just plain cool. I need one of those to keep my sister’s cat in line.

Let’s just hope that cat isn’t curious.

Very cool! I’ve wanted one of those for a long time. Does it start on its own or do you have to get it going?

-- Until you spread your wings, you'll have no idea how far you can walk.

It starts on its own. However, if the gap is set too wide then it will not start. Occasionally it will also “go out” after it has been on for a little while, again it is actually because the initial gap is too wide. It can start up in that case but after the copper tubing heats up and the resistance rises it fails to restart. It also works best if the copper is clean, which it isn’t really in the this video.

Answer: —All the wood the woodchuck could get.

Thats pretty neat. Thanks for the cool video.

-- Wayne - Plymouth MN

Well that’s enough excitement for one night for me ! LOL Great job on the box and the device : )
Thanks for the video as well .

-- You know you're getting old when you know the difference between you're (you are) and your (belonging to you) AND how to use them in a sentence .

Currently the cat is attempting to claw his way to the bottom of an empty cardboard box. Curious does not begin to describe him.

Seriously though, did you have some sort of plans you followed to do this? I vaguely remember reading about this in old school textbooks but it has been quite some time.

where did you get the transformer

-- Do something nice for somebody

No plans, it is actually very simple. Although I think there are a number of ways to build one that is more complicated. This one simply uses a, rather large, neon sign transformer. The inputs of the transformer connect to A/C power, just as they would for lighting up a neon sign. On the two outputs you can connect wire or tubing or the like and simply route it close enough to let it create the initial arc. If it is routed too close to the case of the transformer it will arc back to it, but no harm seems to come of that. The heating of the air by the arc causes it to rise and the widening of the gap causes it to eventually break the circuit. The most important thing is to avoid being electrocuted when playing around with something like this. Some neon sign transformers do not have high enough voltage output to do this and I believe some have protection circuitry which prevents it as well. I’ve also seen them made with oil burner ignition transformers and microwave transformers, though the neon sign transformer is probably the simplest and safest.

The transformer was an eBay find, I think I won it with a two dollar bid but had to pay about $30 shipping. The transformer weighs about 20 lbs. if I remember correctly.

Nice box. How do you access the interior? Does the lid opens?

The electrical part is cool indeed. Although, for those of you seeking to make one, here is a tidbit from the corresponding Wikipedia page:

”Health hazards:

Arcs can also produce a broad spectrum of wavelengths spanning the visible light and the invisible ultraviolet and infrared spectrum. Very intense arcs generated by means such as arc welding can produce significant amounts of ultraviolet which is damaging to the retina of the observer. These arcs should only be observed through special dark filters which reduce the arc intensity and shield the observer’s eyes from the ultraviolet rays.”

Not to demerit the project in any way but, if I were you (or your cat!) I’d be very careful…

-- Jojo, shopless in Kyoto · http://twitter.com/kagushokunin

The base is actually screwed on from the bottom with some large countersunk screws, though I haven’t opened it up since I finished it.

And yeah, I should probably edit my project post to carry those warnings because it is serious stuff for all the reasons that wiki entry points out. It is very dangerous and I seldom power it on. So anybody who may now be thinking about making one please make sure you know what you are doing and be careful.

Damn, there go my plans for curious cat domination. Thanks for all the info guys, it seems like this may be a better science project than a weekend project!

Made a small one in high school with a electric fence transformer for Electronics class.

-- Jimmy, Oklahoma "It's a dog-eat-dog world, and I'm wearing milkbone underwear!"

Very cool. On my list of things to do now.

Here’s another version:

http://www.youtube.com/watch?v=PXiOQCRiSp0

-- Matt - Syracuse, NY

Years ago I saw one that was inverted and the legs swung like pendulums. Then the ends got close together, the spark would start and then climb the rods as they swung apart.

-- Until you spread your wings, you'll have no idea how far you can walk.

Very cool project except all the dangers of lasering your eyes blind and entering a different dimension and blasting holes in the sun, very cool. Nice warning though.

-- Mike. mwurm13@yahoo.com

Nice job, looks cool!

-- Debt is nothing more than the 21st Century's form of slavery.