This is a guide on how to build a medium sized Tesla coil. I built this one from parts I had laying around, all I had to buy was magnet wire, in all I spent less than $30! For those building their first coil, I would not suggest using this a standalone source of instructions. This is my first coil, and I used a multitude of sources to make it. Also, I did the boring math part behind it. At first I tried to skip some of the math, and just "wig it" but that didn't work. For the math part I would suggest deepfriedneon.com, but I found a much simpler site : http://www.classictesla.com/java/calculat.html#WireFreq . Once you know what materials and dimensions you will use, go to this site to get the whole resonance thing synced up as closely as possible. Read this entire guide, and maybe the comments section, before doing anything. Also read some other guides and maybe the Wikipedia article on Tesla Coils before deciding whether or not to embark on a shockingly frustrating, but rewarding journey. I built this for a high school science project, and although I finished at the last minute, it didn't take more than maybe 20-30 hours of work. I entered a few contests with this so you should vote for me if you enjoy this instructable.

I also must say that by using any information in this guide you assume all risks involved with the components, operation, and construction of Tesla Coils or any part of the circuitry described. I do not take any responsibility for injury or damage resulting from the use of this information. Tesla Coils CAN KILL YOU! Whether it be the streamers, 15kV NST output, or the simple (and most dangerous) 120V wall outlet input. All the currents involved with this project are dangerous! I would recommend working with someone experienced with high voltage if you are not. Also, this device is a major FIRE hazard. Use it only outdoors. To sum it all up, this project is risky, be careful.

Step 1: My Understanding of the Inner Workings of a Spark Gap Tesla Coil

From what makes sense to me, the Tesla coil is a magnetic resonator, otherwise just a really powerful transformer. Wall outlet current is converted to 15000 V by the NST, which then charges capacitors, which (once fully charged) allow electricity to temporarily "jump" the spark gap, which allows current to temporarily flow through the primary coil, generating a magnetic field, which the secondary picks up, and converts it back to a current (of higher voltage), which then flows into the ground and into the air (What a sentence!). This process happens 120 times per second or something like that. The Tesla Coil not only steps up voltage but also frequency, which makes the pretty streamers of death that obviously fascinate you (that's why you are here). Due to this high frequency, your nerves would not feel pain from the streamers conducting into your body, but they still cause damage! Basically, your insides would cook and you wouldn't feel a thing, but that is not going to happen because you are not to touch the streamers! Don't do it! Oh yeah, the diagram is from Wikipedia, thanks to another instructable to pointing out to me which one to use. Use the bottom diagram. The top one didn't even work when I tried it, and the bottom one makes more sense.

For the High Voltage transformer, I used a 15kV NST.
For the spark gap, I used two bolts in opposite sides of PVC pipe at a set distance.
For the HV capacitor, I used salt water "Leyden jar" capacitors made of Snapple bottles.
For the Primary, I used .25" diameter copper tube.
For the secondary, I used 24AWG magnet wire wrapped around 1.5" PVC.
For the Torus, I used Aluminum Dryer Duct that I cut open and wrapped around two aluminum pie pans.
Is its necessary that I use a donut shaped top load. I dint get any aluminium dryer duct. Can I use other metallic object with a good enough surface area, maybe like a sphere or something?
Yes, a sphere is the next best shape, and has a slightly cooler effect in my opinion. Whenever I used a sphere I had many small streamers instead of a couple big ones.
If you plan to build a Tesla Coil, DO NOT use these plans! I have much more effective ones that I am currently tuning, and I will publish a new instructable once I am satisfied. The output of this one is too small considering the 1000 watt input. Expect the new guide in about a week or two (depending on when the final part arrives).
Nice instruct able. Well written and illustrated. :D<br>I just have two tips for you:<br><br>1) People aren't as smart as one might assume. I've seen this happen on my own Tesla Coil instruct able.<br><br>2) Try a shorter, fatter secondary. I have seen this common misconception happier to even some of the more experienced coilers. You will get a much better output for all the work you are doing. ( Congrats on getting what you did! )<br><br>A good ratio for secondaries is about 3.5-6 times the diameter is an appropriate height. So say you had 3 inch O.D. PVC, an optimal length would be around 12 inches. Stick by this and you will see a great increase in performance. A side note:<br>As tesla coils use resonant rise, turn count DOES NOT MATTER. Thus, height has no advantage.<br>An exception: on the smaller end of diameters, you want to a ratio of 5 MAX.
Thank you for the feedback. I knew that it would be hard to make this easy to build, so I hope that anyone with questions about the instructions will post a comment, which can help others with similar problems. I didn't realize your point about the secondary until I had already wound it, so I had to stick with it. I have been trying to better tune it, and I seem to have hit a brick wall with the current secondary, so I have ordered more magnet wire to make a new one. I think I will post something about this on the secondary coil step.
<p>This is correct and incorrect. <br>1. It's not 60Hz once it has been transformed.<br>2. If properly built it is harmless. But if incorrectly built it can be dangerous. <br>3. Don't type in all caps. It reads like you're 9 years old.</p>
<p>And it wouldn't be murder...</p><p>It would be negligence... </p>
That is where you are wrong. This happens to be a tesla coil, not unlike the coils Mr. Nikola Tesla himself built. A tesla coil is simply an air core resonance transformer. This means that the frequency of the primary is such that it is tuned to the secondary's natural resonance, which in turn resonates, creating a stepped up voltage beyond what are possible with a convetional air core transformer (one who relies on electromagnetic fields). Now as to frequency, technically, you could make a tesla coil resonating at any frequency. Most coils resonate in the hundreds of kilohertz. Some of the larger coils can be as low as 50 kHz. If you were able to make a coil and top load big enough to resonate at 60 Hz, then you would only have to wrap a couple of coils of wire around it and plug them into the wall socket.<br><br>It is a very common misconception that tesla coils need to run at high frequencies to be considered tesla coils, when in fact they actually need to resonate.<br><br>You also mentioned the skin effect. As MistaStokes said, the skin effect apply very well to human flesh. Instead its the incapabilities of your nervous system
Coil big enough to plug into a wall socket... Would that even be practical or possible? I want to build another, bigger coil, but finding a power supply is difficult.
After saying that, I had to try to see how big it would be and it ends up being like 200 feet tall and 12 feet wide, with 2 toroids being like 400 feet across each!!!<br>It would also use like 10 tons of copper wire!!!<br>Probably safe to say that its impossible.<br><br>I really want to build another coil too. My first one was a little 12&quot; tall coil that throws 6 inch arcs at best and my second was a VTTC that throws 7-8&quot; streamers. I want to see 2 foot arcs!<br><br>I'm having the same problem. I can't find any transformers on craigslist and they are way too much on ebay, well the high power ones are. I might start to call around a at neon supply and repair shops.
I was looking at power pole transformers, which are probably really hard to get and expensive. My idea is that if the power company makes them in a factory, then shouldn't I be able to make one? There are no instructables on it but I bet somewhere on the internet there is a guide on how to make your own pole pig transformer.
How big of a coil are you talking?!? Pole pigs are usually used for coils that like 10 feet tall!<br><br>Pole pigs are very heavy, upwards of 200-300lbs, very hard to come by and very expensive. My guess it that it would be easier to buy one than to make one because it will require a lot of iron (specially shaped) and even more copper wire. I know people have had very good success powering large coils, 4 feet tall or bigger, with nst and microwave oven transformers (MOT). It takes a fair amount of math and understanding to make one that big with good results, but i think its worth it.<br><br>I recommend using a 15kv NST at 30 or 60 mA or 2 MOTs in series with a voltage doubler to get 8kv at a few hundred mA.
If you do the math for &quot;the skin effect&quot; you will find at frequencies up to 300 (such as the ones generated by this and other Tesla coils) the current depth will flow at 60 inches deep in human flesh. It is not safe to touch this or ANY Tesla coil. This is a common misconception because when calculating the skin effect in copper and other metals, the depth is only a few thousandths of an inch, human flesh, however, has much different properties, and the skin effect is not very prominent. The only reason that one does not feel the Tesla coil's streamers is that nerves are not capable of detecting such high frequency. Do not be confused by the lack of pain, they are still doing damage.<br><br>check out here: http://en.wikipedia.org/wiki/Skin_effect and here: http://www.bibliotecapleyades.net/tesla/esp_tesla_17.htm<br><br>Basically DO NOT TOUCH this or any other Tesla coils. The skin effect is NOT enough to prevent permanent nervous and muscular damage, or even worse, cardiac arrest.<br><br>If you want to touch the streamers, get yourself a Faraday suit, like ArcAttack and other professionals do.
Why do I hurt so small output section
Why do I hurt so small output section
<p>Combination of your input (5kv, 10kv, 15kv) and how finely you tune it. Mostly the later. </p>
<p>Can I replace the bottle capacitors with a regular capacitor? If so can you link to where I can buy it?</p>
<p>Hi, Tesla fans! Can I use ignition coils of a car instead of the capacitors made from snapple bottles? Can you help me make a schematic diagram for this? I'm planning to build my son his (and mine, as well) first Tesla coil for his science project. After which, I could add music to it later (which I'll use on New Year's day &amp; 4th of July).</p>
<p>Nice one!!</p>
<p>why is important no to cross wire? it will not work?</p>
Hi, I'm making Tesla coil with 10 000 V, 120 W. What is the inmost distance that in which Tesla Coil can break electrical devices?
Hi, <br>I've made about 900 turns for my secondary coil instead of 1000. Will it work?
could you use any extra 4&quot; diameter PVC instead? <br>
I am getting really close on the construction of this. I cant wait to fire it up only need a few more parts!
UV filter? I know UV is bad for you eyes, I wonder if you could block the UV coming out of the tube. Or maybe just seal it off
Yes, I think it would be a good idea. I attached a shop vac set to reverse to the top, and covered the bottom. Not much light gets out now.
If you want to see the arc but not fry your eyes try these googles. They are cheap and have UV protection lenses sutible for welding. <br>http://www.harborfreight.com/2-piece-welding-goggles-set-35711.html <br>If you have to ship these its proably still worth it but i live by a HF and with 20% off i can get them for about $3.50
if i get a 15kv 30ma transformer, how would the dimentions of the tesla coil change?
they should not change (at least from what i understand) you might need to use less leyden jars because the NST will not charge them as fast
I made a windings calculator with excel 2013 for standard and metric units <br>http://www.mediafire.com/view/?6y7gi6u3qi8miai
really nice ible'! i plan to make a coil exactly like this! (hopefully mine does not set itself on fire lol) i have called neon sign shops and i will get two neon sign transformers as soon as my parents will drive me to the shops that are giving them away. I am about to buy magnet wire and i want a coil 3'' in diamiter too. How many pounds/feet do i need? i would not mind some leftover as magnet wire is usefull. thanks again for the awesome instructable i hope you make more!
as spark light said: &quot;A good ratio for secondaries is about 3.5-6 times the diameter is an appropriate height. So say you had 3 inch O.D. PVC, an optimal length would be around 12 inches.&quot; Length of wire required to create such height would depend on the diameter of the wire. I found my calculations short, and on both projects I ended up using about 100 feet ( ~30m) more than I predicted. It would be good to buy more wire than needed for this reason. I simply took the desired height, divided by the diameter of the wire (including the insulation), then multiplied by the circumference of the pipe to get a rough estimate.
nice instructable! i will try this. just a tip use coaxel cable as HV wire
That's a great idea! It should work, and I will definitely try that since I can acquire very little HV wire.
its the coolest project imade yet
how did you ground your Tesla coil
I drove a metal rod a few feet into the ground, and connected it to the bottom of the secondary coil. Make sure to call your utilities and ask them to mark where utility lines are before you drive anything into the ground, though!
...I'm making a tesla coil for my school science fair, and don't want the coil to be realy dangerous, so could I use about 2-3k v. ???????
Sure. You would have to adjust the capacitors and spark gap, but it should work. To be honest, I kinda over exaggerated the danger on this. As long as no-one touches the transformer or wiring, they would be fine. The arcs coming out of the top would probably not kill anyone, but probably isn't good enough. I have found that it is also safe for electronics beyond 10 feet (within 10 feet my old phone got messed up, it only died once the arcs hit it). The 3kv coming off the transformer is a lot more dangerous than the output of the coil.
ok i will!!!
Hi,I built a TESLA COIL with 5kv 30ma nst.Primary coil made with 4mm<br>copper tube with 10 turns secondary made with 2inch PVC pipe.Winding<br>height 10.2inch(0.315mm enameled copper wire used) also made Capacitor<br>bank with 2kv 0.15uF polyester film capacitor.But the problem is my<br>Capacitor burnt several times but the coil works with LEYDEN JAR<br>capacitor.Why the capacitor burning??????<br><br><br>Please Help Me!!!!!!!!!!!!!!!<br>
Maybe you should try a thicker material or multiple layers of the material. I think the problem is the polyester material is too thin and electricity can arc through it. Or maybe it is not suitable for the voltage. Try using thicker material, or different material.
I like the bit where he says - it didnt catch fire until the 3rd or 4th time!<br><br>be careful be very very careful!
im kinda new to this and already i want to make a tesla coil that you can use to play music like a boss. thanks for the foundation project.
You would need to build a solid state Tesla coil to play music, spark gap ones (like this) are not capable. There is other instructables on that, such as http://www.instructables.com/id/Build-a-Musical-Tesla-Coil-like-a-Pro/
As with all high power/current devices, precautions and safety should be 1st on ones mind, however, when dealing with Microwave Oven transformers, be VERY careful!<br><br>It only takes once to kill or maim...<br>
Great work,just a couple of safety points Circa1990 we experienced with a 4800 watt coil,this is well above all safety levels,built by an expert team,any digital device with in its range running either reprograms,or cancels same.Any neon bulb will light up if held in the hand up to a quarter of a mile.The unit was dismantled afterwards to prevent any further problems. A good fun starting point is yours, wishing you all the best and safe handling.

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Bio: I like to play with the more dangerous DIY stuff, but don't worry, the ones I upload are pretty safe if you follow the ...
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