Step 2: Schematic and Explanation of Operation

The circuit itself is fairly simple.  The transformer steps up 120 volts AC to 12kV AC.  This voltage is high enough to break down the air and cause an arc to form between the two electrodes where they are closest together. 

The arc heats and ionizes the air, which then rises. This hot ionized air is a lower resistance path between the two electrodes, and so the arc continous to follow this path.  The arc rises along with the hot ionized air, until it reaches the top of the electrodes where it cannot rise any higher.  The arc then extinguishes, and forms again at the bottom where the electrodes are closest together.

I'm a little nervous about the wood<br>
OMG! This is AWESOME! I am doing a project just like this for my Wind Turbine Tech/Electricity class. Was wondering if it's worth it? Please advise. Your set up is the BEST by far I've seen. Thank you for sharing.
The greatest expense of a project like this is the neon sign transformer. Ebay is the best source for these. I've always seen suggestions that a person should visit businesses the build or design neon signs and see if they have any working units that would otherwise discard, but I have never tried it. <br> <br>Your class sounds interesting. Is it a high school or collage type class? Wind turbine tech sounds kind of specific (and unrelated to a jacobs ladder), while electricity sounds more broad and open ended. <br> <br>I build my unit just for fun. My kids like to see it work. <br> <br>Good luck with your project!
I just obtained a neon transformer today from a sign shop and was donated to our school for our project! That was cool. Also my wind tech class consists of an electricity class combined. Us students have to know about AC and DC and of course all about Ohm's Law so it comes into play. We are suppose to have a project that contains anything we have learned so far. <br> <br>Thank you for the response and advice. I also used the Surplus sight to purchase high voltage wiring which there are five people in my group and we just split the costs. <br> <br>Thank you again for your insight and support.
Beautiful. Does the arc scorch the inside-top of the case?
It did scorch the top to begin with. I had to trim back the electrodes to the point where that wouldn't occur anymore. <br> <br>You raise a good safety point that I should add to the instructable. I wouldn't want anyone to start a fire by having the electrodes too close to the top. <br> <br>On my unit I had to trim the electrodes so that they are about 1.5&quot; down from the inside top to prevent the arc from scorching plywood.
Definitely lots of safety to watch out for. We just had some discussion 'bout this in the Answers Forum: <p style="margin-left: 40.0px;"> &quot;<a href="http://www.instructables.com/answers/where-can-i-find-very-powerful-transformers-powerf/?comments=all#CF7KISMGFRWPL7I">where can i find very powerful transformers powerful enough to make a 7-12 inch jacobs ladder?</a>&quot;<br> &nbsp;</p> <p> Don't know if Lexan absorbs UV, but that's a real sneaky danger of the plasma discharge.&nbsp; However, I suspect you're safe as Lexan is an organic polymer- most organics absorb UV.</p>

About This Instructable


61 favorites


Bio: Now let's get out of this gas filled hallway before we all suffocate.
More by LargeMouthBass: Audio Delay Module Reverse Engineering an Electric Fence Charger Stop Time with an LED Stroboscope!
Add instructable to: