Jacob's Ladder
They're in the background of pretty much every mad-scientist movie going all the way back to Frankenstein.  You simply have to have one as a prop if you want to have a convincingly demented mad scientist lab.  They are very easy to build since they require nothing more than a high-voltage transformer, three-prong cord (if it doesn't come with the transformer), and a couple metal rods for electrodes.

The central piece of equipment here is a 12,000 Volt transformer.  You can pick these up on eBay or sometimes Craigslist if you live in a metroplex.  They are often sold as neon sign transformers.  Anything from 12k to 15k is adequate.  Prices vary quite a bit.

I feel morally obligated to point out here that there's enough voltage coming from one of these to shock the fuck out of you or kill the fuck out of you, so be careful!  NEVER TOUCH THE LEADS WITH THE TRANSFORMER PLUGGED IN!

By the way, even getting your hand in the arc could lead to serious burns at the very least, so don't do that either.

The leads are metal rods I picked up from Lowes and bent into this configuration.  This shape allows the leads to be "tuned" to achieve a sustained arc going all the way to the top and started up again.

If the leads are too far apart, the arc will not initiate (i.e., it won't spark at all).  If they're too close, then the arc might stay in one spot and not travel.  The longer the arc ignites in one place, the hotter the leads will get in that spot.  So... 


The contacts on my transformer were threaded.  Most are, from what I've seen on other project pages.  The threading allowed me to place a couple washers on each with the leads held between them.

Here's how the power was connected.  Again, be careful.  This wasn't even remotely child-proof.  When we had this running during the Halloween party, I had it out of reach of the guests.  Most people intuitively recognize that it isn't a toy, what with the loud noise from the arcing, but I didn't take any chances since there was alcohol involved, it being a party and all.

I set it up on the porch to test it.  Yeah, my porch is kind of white trashy at the moment, I know, but at least the junk is out of sight from the neighbors.

It's hard to accurately capture a still image of something dynamic and made of light, but this is a decent shot of the arc.

Here it is traveling up.

With low light and a longer exposure, you can get shots like this as well.

Even longer exposure.

Still longer exposure.  You're seeing where one arc started above that break, then the next one beginning and almost reaching where arc was at the beginning of this exposure.

Here's a wide shot of it in the corner of the kitchen.  Admittedly, it's not all that impressive in this shot with all the other props and food and the flash.  This was taken after the party was over and I'd turned the Jacob's ladder off for the night.

Copyright 2010 Alexplorer.