Introduction: Step by Step Plans to Building a 250,000 Volt Tesla Coil. (REVISED VERSION)

In this Step-By-Step process I will explain

1. How a Spark Gap Tesla Coil works.
2. The parts you will need.
3. The price of each part.
4. Safety.

Step 1: The Parts That You Will Need.

The parts you will need to build a tesla coil:

1. 6500 volt 23 milli amp transformer found at amazing1.com

2. 10,000 volt capacitor found at amazing1.com

3. Spark Gap found at amazing1.com

4. PVC Pipe 5-6 inches wide 3 feet long Found At The Home Depot

5. Copper tubing (refrigerator tubing) 1/4th inch diameter 30 feet found at The Home Depot

6. Toriod Found at Amazing1.com

7. 24-26 AWG magnet wire electronixexpress.com

8. Safety Glasses

9. Drill

10. 1/8 Drill Bit

11. Masking Tape

Step 2: Links for Tesla Coils and Other Supplies.

www.unitednuclear.com
www.teslacoil.com
www.tesladownunder.com
www.pbs.org/tesla/ins/lab_tescoil.html
www.powerlabs.org/coil2.htm
www.mos.org/sln/toe/tesla.html
www.richieburnett.co.uk/tesla.shtml
www.teslasociety.com/teslacoil.htm
www.pupman.com/safety.htm
www.angelfire.com/electronic/cwillis/tesla.html
www.tb3.com/tesla/index.html
www.teslasystems.com/gallery/index.html
www.ttr.com/index.htm
www.old-mage.com/tech/Tesla.htm
www.deepfriedneon.com/tesla_guide.html
www.qsl.net/ke5fx/tesla.html
www.tesla-coil-builder.com/double_cone_bipolar_tesla_coil.htm
www.penguinslab.com/tesla.htm
www.teslacoil.org
www.bizarrelabs.com/ind2.htm
www.tfcbooks.com/mall/more/371tcbg.htm
www.teslamap.com/guide.html
www.tesla-coil-builder.com
www.classictesla.com
www.teslamania.delete.org/frames/coilgallery.html
www.geocities.com/CapeCanaveral/Hangar/6160/tesla/tesla.html
www.geocities.com/bob_motz/chipid
www.teslacoils4christ.org
www.lod.org
www.members.tripod.com/~mad_coiler/tesla.htm
www.hbci.com/~wenonah/tommy/td.htm

Step 3: Making the Secondary Coil.

Supplies Needed:

1. PVC Pipe
2. 24-26 AWG Magnet Wire
3. Masking Tape
4. Wire Cutters
5. Drill
6. 1/8 Drill Bit
7. Safety Glasses


1. Get your 3 foot long 5-6 inches in diameter PVC pipe.

2. Get your enameled wire

3. Next drill 3 holes in the side of the bottom of the PVC pipe (about 1-2 inches above the bottom and a 1/4 inch along the bottom of the PVC pipe. this will hold the wire that is wrapped around the PVC pipe.
you will have to make these holes about 2 inches below the top of the PVC pipe and 1/4 inch apart make sure that the wire comes out of the end of the PVC pipe.

4. Next insert the wire through one of the end holes that you drilled and weave it through the other 2 holes (make sure that some of the wire comes out of the bottom of the PVC pipe.

5. Next you will have to get some tape: Masking tape, Electrical tape, Vinyl tape, or Packaging tape will work.

6. Next wrap the wire around the PVC pipe making sure that the wire will not overlap or have kinks or bends in it because this will greatly reduce the amount of voltage that your Tesla Coil will produce. also (make sure that the wire is tightly wound and tightly close together when wound.
IF YOU GET TIRED OF WRAPPING THE WIRE YOU WILL USE THE TAPE FOR HOLDING THE WIRE IN PLACE SO IT DOES NOT UNRAVEL.

7. You will have about 1000-3000 wrappings of magnet wire after you are finished.
after you are finished wrapping the PVC pipe with wire. just put that aside but make sure you have thread the wire through the last 3 holes a the top of the PVC pipe. and put tape over both three holes where the wire in located this will hold the wire in place until later.

Step 4: Making the Primary Coil.

next you will need the copper tubing the copper tubing will serve as your primary coil.
you will first have wind about 20 feet of the copper tubing in a helix or in a flat spiral form making sure not to let any of the other coilings touch each other because this will cause a short circuit.

Step 5: Making the Primary Circuit.

Parts you will need:

1. 6,500 Volt Transformer
2. Spark Gap
3. 10,000 Volt Capacitor
4. Three Prong Electrical Cord (Grounded)



You will need to hook up your transformers 2 skinny leads to an electrical cord with 3 prongs and you will have to hook up your transformers 1 input lead to the electrical cord and do the same with the other input lead. Then hookup the capacitors 1 lead to the output lead of the transformer and do the same thing to the other lead of the capacitor. Then hookup one of the leads of the capacitor to the spark gap. Hookup the spark gap to the outer ring end of the primary coil. Hook up the other end of the primary coil to the other end of the spark gap.

Step 6: Making the Secondary Circuit.

Find the Ground lead to the 3 prong cord it is usually green or it is bare. Then hook it up to the lead hanging out of the bottom of the secondary coil then solder it and put electrical tape over it to avoid short circuiting. And do the same to the other bare input leads of the transformer. Now secure the secondary coil to the top base of the Tesla Coil.

Step 7: Adding the Toriod or Topload

Parts you will need:

1. Toroid
2. Secondary Coil


The Toroid is the top load of the Tesla Coil it is where the arcs form.
To connect the Toroid to the Tesla Coil just put the wire that is hanging from the top of the Tesla Coil in the Toroid by either soldering, brazing, or with a screw.
Then fasten the Toroid to the Secondary Coil

You are finished with your new companion.

Step 8: !!!WARNING!!!

!!!WARNING!!!

!!!WARNING THIS TESLA COIL AND ALL OTHER TESLA COILS CAN AND WILL INTERFERE OR DAMAGE PACEMAKERS, COMPUTERS, AND OTHER ELECTRONICS.!!!
!!!DO NOT TOUCH THE COPPER TUBING (PRIMARY COIL) OR THE (SPARK GAP) WHILE THE TESLA COIL IS IN OPERATION IT WILL KILL YOU INSTANTLY THERE IS NO SECOND CHANCE!!!
TESLA COILS ARE VERY DANGEROUS AND SHOULD BE TREATED WITH THE MOST CARE AND RESPECT: IF YOU DO NOT HAVE KNOWLEDGE OF HOW HIGH VOLTAGE AND ELECTRICITY WORKS DO NOT BUILD THIS PROJECT UNTIL YOU HAVE EITHER READ UP ON ELECTRICITY OR GET EXTENSIVE TRAINING. ALSO DO NOT LOOK INTO THE SPARK GAP WITHOUT WELDERS GOGGLES. IT IS VERY DANGEROUS TO OPERATE THIS TESLA COIL WITHOUT SAFTEY GLASSES. BUT MOST OF ALL ELECTRICITY AND MIND ALTERING DRUGS INCLUDING ALCOHOL DO NOT MIX!!!


IF IN DOUBT E-MAIL ME AT jtmotz@hotmail.com I CAN GIVE YOU VERY USEFUL INFORMATION.

DISCLAIMER:
I WILL HAVE NO LIABILITY IN ANY DAMAGE OR FATALITIES THAT THIS PROJECT MAY CAUSE.

Step 9: Contacting Me

If there is, any questions or problems with this project email me at jtmotz@hotmail.com

Step 10: Price List

1. 6,500 Volt Transformer $59.95
2. 10,000 Volt Capacitor $59.95
3. Spark Gap with cooling fan $59.95
4. 24-26 AWG Magnet Wire $15.50
5. PVC Pipe $20.00
6. TORIOD $59.95
7. Copper Tubing $30.00

GRAND TOTAL.............................. $305.30

Step 11: How a Spark Gap Tesla Coil Works.

The Tesla Coil is an air core resonant transformer consisting of a primary coil and a secondary coil. The primary coil is the part of the device that resonates or vibrates which when vibrating gives of a very strong magnetic field that causes induction in the secondary coil. The magnetic field is caused by, first the power from the 120 volt wall outlet is converted into 6,500 volts by the transformer then the power flows into the capacitor where it gets amplified then moves along to the spark gap. The spark gap acts like a switch, without the spark gap the coil will not function it will just burn up your transformer; next the power goes to the primary coil and causes induction in the secondary coil thus causes lightning or arcs to be transmitted out of the toroid or topload.

Comments

author
KingofHeart4711 (author)2016-06-08

I'm sorry to be rude, but if someone want's to build a Tesla coil, these are not the instructions you should follow. It does not seem like the author took into account any of the physics behind how a Tesla coil works. A Tesla coil is an LC (inductor-capacitor) circuit, the primary and secondary coils being the inductors, and the capacitor (obviously) and the top load being the capacitors. The values of the capacitors and inductors matter, without getting into the physics too much, there is a proportion to the two circuits (the primary and secondary) , so that the system is resonant. With how poorly the secondary is wound here, I doubt that the author had any specific inductance value in mind, and same goes for the primary. The final nail in the coffin is that the capacitance of the capacitor is not even specified, so this was clearly assembled without much thought. Like the author said at the end, the Tesla coil relies on resonance, but only by some crazy odds could this system be resonant. That's not to say that it won't produce sparks if it isn't resonant, but you would be wasting a lot of the power from the transformer, and would get some very underwhelming results.

To follow these instructions would be a colossal waste of money. www.teslacoildesign.com would be a great place to start if you're serious about building a Tesla coil and understanding how it functions, but there are plenty more out there, and it is a good idea to read many, as everyone does something slightly different, so its good to cross reference the instructions to find the most widely accepted methods.

author
Jose EribertoP (author)2014-10-06

Hi, Tesla peeps! Can I use ignition coils of cars instead of capacitors? Can someone help me build one that is in Solid State? I'll be helping my son build his (and mine, as well) first Tesla coil for his Science Project (one that could play .mp3 music from his iShuffle). After which, we could use this on New Year's day & 4th of July. This has to be done on or before December (2014).

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EdwardP4 (author)Jose EribertoP2015-12-15

Just from my experience dc is way more dangerous than ac

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GarethT7 (author)EdwardP42016-02-26

DC does not allow flexion of muscles nor will it hit you off the source of the shock - think Electric Chair !!! Not many walking away from that ! Goes right back to the original AC/DC for electric transmission in America....Edison had the light bulb and the other guy had the electric chair !!!!!!!!

author
SilverF (author)Jose EribertoP2014-12-10

Did you ever get any info on a solid state coil? After watching my fiancé enjoy the struggle and hate it so much at the same time, I was sucked in and developed an interest myself. Your finish date was "on or before December 2014" and Im curious if you guys completed the project or change to a different project? Im a newbie to all of this electrical stuff but you said it was for a Science project, leading me to believe that if he is still pre-HS grad, that I might be able to successfully understand it enough to make myself useful without extensive experience.

author
Jose EribertoP (author)SilverF2015-01-15

Hi SilverF. Nope, no info from SSTC (solid state tesla coil) from tesla peeps. My son (Jacob) wanted to have a different project. His classmates (upon knowing his project) wanted to have the same project. He wanted to have the "Jacob's Ladder" instead. I've found out from here that it's easier to build. You can check out the "Helix" type of Jacob's ladder. That, we plan to build!

author
micko75 (author)2015-03-24

Hi science peeps, interesting topic, i want to build a 12volt tesla coil combine it with solar and run 12volt appliances, not so dangerous i guess, any info on 12volt tesla instruction would be very much appreciated . I'm not much of a science guy but i want to play with a home project.

Kind regards.

author
_CrashA_ (author)micko752016-01-17

A 12v Tesla Coil needs 12 volts to run. That will then be stepped up to a few thousand volts on the output (top load) of the coil. So yes it is dangerous. If you want to run 12v appliances, then use a 12v power source.

author
MohamedT29 (author)2015-11-08

if my output voltage 5000 volt , then i want to know the length of the tube and its diameter and how many turn should i rotate the magnetic wire on it and the secondary too ???

author
_CrashA_ (author)MohamedT292016-01-17

There's a few apps on the app store for smart phones that can do all the calculations for you as long as you have all the values.

author
Rfmhz (author)2015-01-24

Here back in the days tesla never had that crap so how Amazon? .anyway a spark from your lighter can do it .ive tried it and guess what no more scottish power for me no more bills .ive got the tesla coil running everything in my house .scottish power meter can go back to them no longer needed lol

author
_CrashA_ (author)Rfmhz2016-01-17

Well good for you powering your house from a lighter. Meanwhile the rest of us are thinking in reality.

author
bmayberry1 (author)Rfmhz2015-11-16

rfmhz. i wanted to ask you how you powered your home from the tesla coil. i am at bmayberry@juno.com . there are three of us working together here. thank you much.

author
Xellers (author)2010-04-16

I know that it has been a while since this was posted, and quite a while since I last visited this page, however, I feel the need to point out that this Tesla Coil does not work and following these plans is dangerous. The author claims that he has achieved sparks that were a few inches in length. Unfortunately, given his apparent understanding of his device and given how poorly it was constructed, even these mediocre results seem somewhat far-fetched. At the moment, I am trying to communicate with an admin to have this instructable temporarily removed until it is made to be up to par with the community standards of this website. Posting dangerous instructions about topics which one does not completely understand not only does you disservice by slandering your name, but it also puts the entire community at risk. Attaching warnings such as "IT WILL KILL YOU INSTANTLY THERE IS NO SECOND CHANCE!!!" does not help.

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DevCoder (author)Xellers2010-06-06

I highly agree, everything about this coil looks dangerous. Please, for your own safety, make a proper Tesla Coil, meaning not having the power switch next to the primary, which can more than easily kill you.

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fss1704 (author)DevCoder2014-10-17

you don't even know what you're talking about.

author
Xellers (author)DevCoder2010-06-07

This instructable needs to be removed before someone kills themselves.

author
fss1704 (author)Xellers2014-10-17

Yeah, let's ban the universe from generating high voltages, lets change the laws of physics to limit the voltage in everytinhg to 5v, then after that lets change the law of gravity too, because gravity can kill you and there's no advice that gravity can kill, and after that let's ban water too, because we doesn't know what's in that water, let's drink just coke cola, we know that coke cola don't kill right?

author
LaserDave (author)Xellers2012-05-14

Now THIS is why innovation and information suppression is alive and well - it's from some people believing that they are entitled to censor others because there is the possibility that a small handful of people *may* make a mistake, causing potential personal injury. Why do you feel that someone's lack of ability should ruin it for everyone else, especially those who CAN safely work with high voltages?

This is a situation where some feel the need to remove other people's freedom to make choices for themselves, catering to those who cannot (or will not) take responsibility for their own actions. If someone decides to build this project, that same someone needs to understand their own limitations before starting, then choose to build it if they feel they are within those capabilities - and does so at his own peril. Even those fully qualified to work on this sort of thing DOES SO AT HIS OWN PERIL, accidents happen to everyone.

I like the project, I am quite capable of working with high-voltage safely, why should I not have the the freedom and opportunity to benefit from this idea, merely because there are a handful of people that *MAY* attempt it and fail.

If someone is not qualified to drive a car, drives anyway and kills themselves, do we get rid of cars because this is a real possibility? Do we outlaw swimming because those who are inexperienced might drown? If the citizens of some countries weren't so quick to assign blame and sue another for their own misfortunes - a result of their own poor choices, clumsiness or simple stupidity - this "Nanny State mentality" would not be required. To shift the onus and responsibility for a hobbiest's safety onto the shoulders of those presenting the ideas and material to the masses, to the extend that it does, is almost unheard of in other countries. These people need to be aware of their own abilities or lack thereof.

And yet, prior to these last few decades of being legally responsible for others if they follow your suggestions, it was already a natural-developed tradition, out of common courtesy and care for his fellow man, that potential risks and dangers were pointed out in the interest of safety, that may not have otherwise been apparent.

I'm absolutely in favour of including a paragraph that clearly draws one's attention to areas where potential dangers and unique risks may be lurking within the idea or project, including personal observations or experiences, and suggested ways to minimise those risks. But it has gone WAY TOO far when it's required that someone sharing an idea has to nervously state he is not responsible, the publication is not responsible, the company and it's shareholders are not responsible etc. if you have an accident. GET REAL!! Handholding and babysitting that extreme and overprotective stifles innovation and creativity because many are too scared of being liable for another's actions... ruining it for everyone, including those enlightened countries able to enjoy such information.

*As an example (in an entirely unrelated field) - there exists an arrangement of huge, outdoor machines that move with such speed and force that you would be instantly killed if you got too close. That situation is prevented with elaborate gate and fence configurations of an exact height and grid spacing, including locking mechanisms and signage. In Europe, however, the exact same arrangement exists, but without the fences and paranoia - people there ARE responsible for their own actions and misfortunes. The machines?? Amusement rides at the carnival.

Sometimes people have to be able to skin their knees to understand that you need brakes on a go-kart. Making people walk through life in sheets of bubble-wrap and sewn-on mittens is not fair to those who won't fall-down-go-boom.

I'm not attacking anyone, especially you. I'm merely pointing out to those calling for the removal of this article that even the "scary and dangerous" projects deserve to exist for the overwhelming majority, and those who want to use them.

Everyone, please be careful when working with high voltages, and recognise whether or not you are experienced enough to safely build such devices. There is NO shame in asking for assistance from those who do have the experience needed to successfully and safely build and learn from this device, and others like it. If you are unclear about something, ask - but if you have the slightest doubt of your capabilities, try a similar project that is less risky to develop the skills you need to move up to a more challenging one.

Bottom line - BE SAFE - but the plain reality is, if you do mess up, it's your own fault.

Thanks for listening. Peace!

~Dave

author
The Asian Cow (author)2013-05-16

Do the direction, spacing, and shape of the primary coil matter? It sounds like you can "tune" it for maximum spark length but if I just set it up in a coil or helix with no measurements will it still produce something?

author
studiobil (author)2011-06-02

DANGER -- DANGER - DANGER

!!! THIS COULD KILL YOU !!!

PLEASE REMOVE!!!

author
KylerKraus (author)studiobil2013-03-21

so?

author

can i use a flyback transformer driven with a 2n3055 driver for a tesla coil

author
LaserDave (author)studiobil2012-05-14

Any electrical project "could kill you" if you make the right mistakes.

Everyone has the right to have access to this material. Why remove it simply because there *may* be a few people that fail or get hurt as a result of not knowing what they are doing? That's called CENSORSHIP!

Drinking too much water can kill you, crossing the street can kill you, eating (and choking on) a meatball can kill you. Life is full of deadly risks every single day. It's ENTIRELY your job to choose for yourself those tasks you are capable of doing, in a manner that will minimise the risks.

It's all about choices, and living (or not) with the results of those choices.

Peace!

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skatattookid (author)studiobil2011-12-06

so can lots of things....you just have to know what your doing.

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DANAN99 (author)2011-07-02

your secondary can also look like this

photo.bmp
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stu2theMax (author)DANAN992012-11-18

Easier to make and almost as efficient

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plasmaniac734 (author)DANAN992011-10-23

thats not a secondary, its a primary

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minh634 (author)2012-04-23

will it work with a flyback transformer?, also if it doese i need to know what wires hook to wat and how its getting electricity? batteries, mains?

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Tesla Coiler (author)2009-02-11

I am surprised that you survived that encounter with that microwave oven transformer there is some nasty current levels in them things, you are looking at about 20 amps or amperes from a microwave oven transformer. That is my guess because they will make a nice arc with a monstrous buzzing or humming sound, and you can feel the heat off of the arc from a couple of inches away. I have been electrocuted by the 6500 volt transformer on accident. I was doing a demonstration for my science class about 4 years ago and I brushed up against both of the HV leads it felt like getting punched in the chest and being pulled extremely hard and quickly. But the current that the 6500 volt transformer was creating was only 23 miliamps. That is half of what is needed to stop a human heart. You were very lucky to survive that electrocution. Be very careful.

author
Xellers (author)Tesla Coiler2009-02-20

You obviously need to learn more about high voltage. If the maximum current that is necessary to trip your breaker is 15 amps, then how could a step up transformer possibly give more than that and not trip the breaker? You don't need to know much about MOTs to know that they honor the known laws of physics. The actual number is about 0.5 amps, or 500 milliamps depending upon the size of the transformer. While this is still very deadly, and you are lucky if you survive a shock from one, you really need to know what you are dealing with before making foolish assumptions like you did.

author
Tesla Coiler (author)Xellers2009-02-20

you can maximize the amperage by using thicker wire, I use a generator to run my experiments. I don't use the mains to power my transformers due to the fact I don't want to run up a high bill. please don't tell me what I do or do not know.

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Xellers (author)Tesla Coiler2009-02-21

Thicker wire, while more efficient, will not make a significant difference unless you are running a power company that distributes electricity throughout town. In any case, if you run a MOT unballasted, then the core will quickly saturate and it will keep trying to draw more and more current. Even if you were to have an infinite amount of power that you could feed into it, it would burn out rather quickly without ever reaching anywhere near 20 amps on the output side. If you really want something that deadly, wire a distribution transformer (pole pig) in reverse and try to build a Tesla Coil with that. It's been done before. I wish I had a generator....

author
f.3 (author)Xellers2012-03-14

I am new to this so yeah go ahead and tear my head off and spit down my throat like everyone seems to do these days with their fake online lives. I am not here for a peeing contest. On the contrary I would like it if you people put them beautiful brains together to sort out problems. I mean really you two are so smart then why are you saying that your using the "Grid" or an "IC" engine to power a device meant to (grow) electrical current from the 1800's? My challenge is for you two to put your minds together to generate electricity that you can grow with this device without the use of the Modern Grid electric and or an IC. Ha I even know the answer to this one.. I'm sure we all will be waiting for yours. You two get along and you can do it, we all have a lot to learn from each other. Oh and if you bark at me not only will you not get my answers but you will also get laughed at. I find these fake online identities hilarious. People will say in an instant on here what they fear they my say in REALITY or REAL LIFE so please treat this like its a part of your real life. Good luck and your clue.. perpetual motion.. another great one from way before our time that nobody has had the presence of mind to exhaust the possibilities of yet.

author
Tesla Coiler (author)Xellers2009-02-21

that is my plan to use a Pole Pig. but I don't have the money to do that yet I first have to get through college then I should have the time and money to do that. Pole Pigs that I have seen are anywhere from 1000-10,000 dollars depending if they are used or not. I plan on getting a new one. But then I will need a variac and one massive Faraday Cage, not to mention alot of space and a bigger generator.

author
Xellers (author)Tesla Coiler2009-02-22

I've actually heard of people getting their hands on them for only a hundred or two, but be careful, these may be illegal to operate in some areas.

author
Xellers (author)Xellers2009-02-22

By the way, if you can, please post some pictures of your coil in action. I really want to see it.

author
Tesla Coiler (author)Xellers2009-04-21

My Pictures and videos will be on the way in 2 days I finally fixed my Tesla Coils secondary coil and capacitor. I am now getting 3 inch arcs even though that is not much but it is a start. as soon as I get that pole pig I will have some real fun. the next coil that I am making is going to be 7 feet tall powered with 4 neon sign transformers and 100 capacitors, with a rotary spark gap, the primary coil will be adjustable by remote control, the spark gap also will be remote controlled for adjustability, the toroid will be 2 feet in diameter, 10,000 wrappings for the secondary coil, and 20 wrappings for the primary coil. there will be a generator built in to the power cabinet. I am expecting arcs to be 15 feet long from this monster. I hope this works out because this will be alot of money to build.

author
Xellers (author)Tesla Coiler2009-04-25

10,000 windings on the secondary coil? Tesla Coils work because of resonance, the turns ratio is more or less insignificant. Instead of more windings, you should use thicker wire. 1000 turns is about right. How will you make the primary coil adjustable;le by remote control? The Tesla Coil will disrupt any such electronics. Also, even if you use 4 16kV 60ma neon sign transformers, the maximum spark length (with 100% efficiency) is less than 10 ft. I used the formula found here: http://www.deepfriedneon.com/tesla_frame6.html to calculate this.

author
Tesla Coiler (author)Xellers2009-04-25

I am also trying to figure out how many Kilovolts my Tesla Coil is creating. is there some sort of formula that I can use.

author

Here is a list of problems that I am having with my Tesla Coil I am having trouble locating a toriod Locating a brand new NST at 15KV 60MA I am not sure how to attach the toriod Is there a special motor that I need for a syncronus rotory spark gap I need help finding new capacitors that are compatible with a Tesla Coil What type of capacitors should I use

author
Xellers (author)Tesla Coiler2009-04-26

Why don't you try to improve your existing Tesla Coil first? Try to make it give 12 inch sparks. Toroid: For your first few runs, you might not even need one. But later on, you can buys something on eBay, but they get expensive. The spherical ones work worse, but are cheaper. If you really can't afford it (like me), then try to make your own. There are many instructions out there on the web. I have not yet had to make a good one because my Tesla Coil is very small and I just use some balled up AL foil;. For anything serious, you will need to make an investment. NSTs: The transformers are the hardest part. Your project sounds big, and expensive. On eBay, these type of transformers go for dozens of dollars each. I recommend that you use MOTs instead for this coil. This will save you a great deal of money, but you will need to have multiple ones to get a high enough output voltage, and I recommend that you also use a voltage multiplier. Tesladownunder has a good example of a MOT powered coil. Look at his schematics. You could also use a single ballasted MOT with a 5 stage multiplier for a slightly smaller coil. Attaching the Toroid: Attaching the toroid is hard because you want to prevent coronal discharges except from the toroid itself. Unfortunately, you will always experience losses, but there are ways of minimizing them. I admit that I have no experience with this, but I would imagine that you take a nut and bolt and attach them through a short piece of wood. This piece of wood should then be fitted into the very top of the secondary coil, in such a way for the bolt to stick out of the top of the secondary. Then, you proceed to soldier and wrap the top wire coming out from the secondary coil around the bottom of the bolt. The topload ism then screwed onto this bolt. If this isn't clear, then tell me, I will draw a picture. Spark Gap: I too have little experience with rotary spark gaps, but I do know how they work. You can use any type of motor as long as you can control the speed that it spins at. Be it through pulse width modulation, a variable resistor, or a lamp dimmer, you need a very fast motor that you can slowly bring from zero to several thousand (or more) rpm. The contacts on the gap need to be very close together so that it fires each time. This requires very good construction and a decent investment of time and money. Capacitors: Don't use ceramic disk capacitors. Use polypropylene or similar capacitors. I think that anything you find on eBay sold as a "Tesla Ham High Voltage Capacitor" should work fine. Voltage: The voltage that you are creating with your coil can only be estimated using the length of the sparks that you create. This also depends on your altitude, the relative humidity, and many other factors. However, you can usually make a decent estimate using data tables found oj the internet. You will never be exactly right, but you will be able to tell if you coil is making between 100 and 200 kV or 200 and 300 kV. If you need any more help, feel free to ask.

author
Tesla Coiler (author)Xellers2009-07-02

I have another question you said that you can't boost the amperage of the 120 volts 15 amps that flows from the house mains by using a transformer but how do arc welders boost the amperages?

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tristantech (author)Tesla Coiler2010-03-25

Because an arc welder uses a lower voltage with a very high current. It exchanges voltage for more amps. It's called a Step Down transformer

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Xellers (author)Tesla Coiler2009-07-03

I said that you can't boost the amperage with a STEP UP transformer. However, with a STEP DOWN transformer, you can.

Voltage * Amperage = Wattage

Therefore, you can use the same amount of power either by having a high voltage and a low current (as with a step up transformer), a medium voltage and current (as with the mains), or a low voltage and a high current (as with an electric welder). Look at the instructables on converting MOTs into arc welders. All of them call for you to remove the original secondary windings on the MOTs and wind your own secondary that is only a few turns of heavy gauge wire. This changes them from STEP UP transformers that produce approximately 2kV at up to an Ampere, to STEP DOWN transformers that produce about dozen or two volts at several dozen Amperes.

I hope that this answers your question. By the way, where are the pictures?

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Xellers (author)Xellers2009-05-15

Pictures of sparks coming yet?

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Tesla Coiler (author)Xellers2009-04-21

I am trying to use a mirowave oven transformer for my Tesla Coil, and I am having some trouble with hooking it up to my primary circuit. I am not getting the arcs in my spark gap and I keep tripping my breaker system each time I hook the MOT up to the Tesla Coil. I know that we don't really get along but this has been very anoying. is there something that I don't know or is there something different that I need to do?

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Xellers (author)Tesla Coiler2009-04-25

Yes, there is a very simple solution to your problem with the circuit breaker. All that you need to do is add an inductive ballast. Every time that you turn on the MOT, it tries to draw more and more current as the core becomes more and more saturated, eventually it draws more than your breaker can handle. If you add an inductive ballast, this problem will go away. Either wire one from an old mercury vapor lamp in series with the MOT, or even use another MOT with its secondary windings shorted out in series with your MOT. This also current limits the output of the MOT that you are using.

The problem with the spark gap is a bit harder to solve. Use a voltage multiplier or two MOTs in an antiparallel configuration. 2kV is not quite enough to power a Tesla Coil. Here is an example of three MOTs being used in a 4kV power supply. One is used as an inductive ballast, and the other two are in anitparallel: http://www.andreas-kilchenmann.ag.vu/index.html (look at his MOT stack page, note that the site does not always work). The spark gap itself is also harder to construct. The high current of the MOT will quickly vaporize the ends of the gap, so it will become wider and wider until it no longer works. The solution to this is to use tungsten electrodes and a fan. You can also use a rotary spark gap. I once tried to make a MOT powered Tesla Coil, but problems with the spark gap forced me to abandon my hopes. I hope that you will enjoy better luck.

Also, if you still have any questions, or need to know more about inductive ballasting, feel free to ask.

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Electrocution is ALWAYS fatal, it means Killing by electric shock.

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Dero.von.Hesse (author)2011-06-16

This design looks frighteningly dangerous. I'm not sure on exactly what would happen once activated, but I'm sure an event similar to the climax of Raiders of the Lost Ark wouldn't be far from it.