3 Simple Ways to
Share What You Make

With Instructables you can share what you make with the world — and tap into an ever-growing community of creative experts.

PhotosPhotos

Share one or more photos of a project, recipe, or whatever you've made, quickly and easily.

Step by StepStep-By-Step

Share your step-by-step photos with text instructions of what you made so others can do it too!

VideoVideo

Share your how-to video. You'll need your embed code from a video site such as YouTube.

How to build a Tesla Coil

Step 7Start it Up!

Start it Up!
Bring it outside for it's first run, as it really isn't safe to run anything this potentially powerful indoors, there is a high risk of fire. Flip the switch and enjoy the light show. My NST, at 9Kv at 30mA, makes the coil give off 6 inch sparks. See it below:



« Previous StepDownload PDFView All StepsNext Step »
86 comments
1-40 of 86next »
Apr 10, 2012. 7:35 AMFreezeNotice says:
Excuse me, my NST doesnt have a pull cord to turn it on its just something like this http://www.ebay.com/itm/Allanson-9000-V-9KV-30ma-Neon-Sign-Transformer-NST-Tesla-Coil-Jacobs-Ladder-/180857678565?pt=BI_Circuit_Breakers_Transformers&hash=item2a1bf52ae5

how do i turn it on or off?
Feb 24, 2011. 4:24 AMdjbaha says:
Hey,what's that black box in the left down corner? I need its voltage to make tesla coil. I think it's kinda transformer.. Message me please.
Feb 24, 2012. 7:39 AMfun bags says:
it is a transformer but dont get A SOLID STATE TRANSFORMER IT WONT WORK
May 31, 2011. 4:41 PMMRBADASS says:
i have a question, how did u ground the secondary coil??
Feb 24, 2012. 7:37 AMfun bags says:
hook it up to the capiciters
Feb 9, 2010. 12:43 PMbigdog19952 says:
im confused wher does the secondary get attatched?
May 25, 2011. 10:44 AMkve23 says:
it doesnt get attached the primary creates some kind of electronic field absorbed by the secondary
Feb 24, 2012. 7:37 AMfun bags says:
exactly
May 24, 2011. 5:53 AMadamnsmith says:
ya bigdog19952 is right it doesn't say anything about where to connect the secondary. and not much description for the primary )=
May 24, 2011. 2:05 PMjj.inc says:
The schematic really helps, I had no idea either before it. Basically attach the primary across the two neon sign transformer HV outputs and the primary you. The secondary has one end attached to the base plate, and the other goes to the discharge dome.
May 25, 2011. 6:19 PMadamnsmith says:
wait i forgot but is the base plate the nst because my dad made his transformer from scratch and that only has one outlet and i have to hook up the ground seperately from an extention cord and like devcoder said that if you hook the primary to the secondary then your whole house will get fried. after i posted those comments before i thought that the primary connects to the top load (circular metal discharge thing), and the topload then connects to the secondary coil and the secondary coil would connect to the ground. but then i thought that then the secondary would be useless. other than that everything i got is fine. i need to know the wiring before friday because that is when my presentation is due. please reply. thanks
May 25, 2011. 7:54 PMjj.inc says:
Here is a complete schematic I made and it should be made to fit your situation perfectly. For the start I recommend doing it as I have shown, but if it doesn't work connect the first two grounds. I threw this together really fast in paint so if you have any questions or if something is not the same as what you have please tell me, I am really happy to see you do this as a project. Be sure not to connect anything across the big red line I made, that will fry your house. The final thing is that you need to not worry about the base plate. I was wrong with it. I just meant the little metal thing the PVC screws into to keep it upright. Good luck!!!
Click the photo and if it doesn't get bigger right away click the link with the highest resolution.
Feb 26, 2012. 7:39 PMsmoothisfast1 says:
Whenever I hook up a wire from the negative side of the capacitors to one end of the primary coil, the spark gap fails to fire. It only works if I only hook one lead to the primary coil - the positive.
Feb 28, 2012. 6:33 PMjj.inc says:
You, Sir, are brilliant and just solved all my problems. Now, I just need to buy some capacitors to replace the one I threw away and rewind my primary.
Mar 3, 2012. 9:22 PMsmoothisfast1 says:
Happy to help
May 27, 2011. 9:41 AMred_green says:
if i eliminated the ground on the secondary, would it create a better display?
i ask this as i don't want to have to ground it directly into the ground.
also, i wonder why you couldn't connect the three grounds together to eliminate any more grounds to condense it into one outlet.
Jan 22, 2012. 3:24 PMred_green says:
i have been thinking, and i think that the electricity would take the path of least resistance (down into the ground), or are all you talking about it like high pressure water in a pipe with holes in it???
Jan 4, 2011. 8:40 PMstevo-d says:
Ummm, harmful amounts of UV light appears to be visible at your spark gap... I'm no expert here, but from what I've read, you really should have that enclosed for the safety of your eyes... Has been described elsewhere as like watching an arc welder, and use arc welding eye protection if you DO NEED to look at it for any reason.
Jan 27, 2011. 5:50 PMsam48415 says:
Your probabally going to get hurt anyway, so it doesent matter. I highly doubt that it is as bright as an arc welder, and will harm your eyes that much
Jan 28, 2011. 4:47 AMstevo-d says:
Well you're right that it would not be as bad as an arc welder because if it was, it would probably melt the terminals!
My point is however that high voltage arcs do indeed produce harmful ultra violet light and just letting anyone intending to do this know to take caution.
As for "getting hurt anyway", I will disagree... Again, we should take caution... Make some pretty sparks, but DON'T make yourself part of the circuit!!!
Jan 28, 2011. 12:16 PMsam48415 says:
Yeh i agree, dont be a conducter of that circuit, it will mess u up. Now that i look at the bottom, where the spark gap is, it looks kinda bright, take caution
May 27, 2011. 9:29 AMred_green says:
so what would happen if i used a semi-silvered mirror to protect the spark gap, but still let u see the spark?
Jun 23, 2011. 10:10 PMsam48415 says:
I wouldent bother...
May 29, 2011. 7:11 PMstevo-d says:
I'm not an expert in light radiation, but I would bet you would still get UV reflecting off such a mirror.
I used to work with high intensity UV light equipment for curing acrylics and we needed to be able to watch it... We worked with the work-piece and light source behind a thick (5-8mm) piece of orange transparent perspex - you could still see the light shining, but it no longer appeared blue and no UV would get through.

I would also like to mention that the equipment I worked with was an arc lamp that sent the UV through an optic-fibre cable - the light coming from the end of the cable would easily set tissue paper on fire, and a few careless co-workers got some nasty burns.

UV LIGHT IS DANGEROUS - Be careful.
Jun 21, 2011. 11:08 AMjj.inc says:
How on earth does yours work, it sure doesn't meet resonating specks, I am trying to make on getting it to resonate isn't working out so well math wise, I think I am just going to go with it because on this page, http://teslacoils4christ.org/TCFormulas/TCFormulas.htm
my numbers for secondary inductance are coming out thousands of henries apart
Jun 18, 2011. 5:54 PMjvictor says:
I made a working tesla coil, and I grounded it, why it has a violet - red color of the spark. I got zapped once for 2 seconds. but i was ok
Feb 17, 2011. 4:08 PMcreatorborg says:
Can you give me a more detailed description on the wiring? I really want to build this for a nikola tesla display i am doing, but your wiring diaramma confuses me.
Thanks in advance, me
May 25, 2011. 7:37 AMadamnsmith says:
ya me too
May 24, 2011. 5:55 AMadamnsmith says:
i wonder if you could make a mini hand held tesla coil with a few 9 volt batterys
Apr 19, 2011. 10:33 AMweeven says:
Where did you get that black box, cause Im using these plans for a school project, please tell me what that is and if possible more in depth instructions. Message me asap
Apr 23, 2011. 3:42 PMJimmy Proton says:
Its a high voltage transformer, probably a NST.
Apr 14, 2011. 4:47 PMaweis says:
what did you use as a power source?
Apr 8, 2011. 9:20 PMjesusdiedforme says:
Ohh my goodness, this is so cool!:D i love love love it!
Feb 20, 2011. 3:16 AMspark light says:
Have you tried tuning it?
Jan 20, 2011. 7:33 AMspikeracooba says:
can i use more than 1 set of the snapple bottle things
Jan 6, 2011. 2:39 PMmalik98 says:
can i use 14 awg wire on the secondary
Jan 5, 2011. 4:28 PMmalik98 says:
i'm using 200-250 ma is that safe
Dec 16, 2010. 11:04 PMKeegards32 says:
where is it being discharged to? and how is it grounded?
1-40 of 86next »

Pro

Get More Out of Instructables

Already have an Account?

close

All Steps Viewing
View all steps of an Instructable on the same page when you're a Pro Member.

Upgrade to Pro today!
79
Followers
6
Author:DevCoder(My Hompage)
Devin is a cool guy, eh doesnt kill himself while doing stupid things, and doesnt afraid of anything.