How to build a Tesla Coil

Step 7: 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:

Comments

[stevo-d]

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.

[sam48415]

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

[stevo-d]

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!!!

[sam48415]

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

[red_green]

so what would happen if i used a semi-silvered mirror to protect the spark gap, but still let u see the spark?

[eichermacher]

Semi-silvered mirror might work, but a few filters to filter out most of the light would work just as well. Rosco has UV filters you can buy, as well as good filters you could use to filter out most of the visible spectrum. That way you'd be able to see the spark but wouldn't have to worry about the intense light.

[sam48415]

I wouldent bother...

[stevo-d]

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.

[red_green]

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.

[red_green]

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???

[eichermacher]

Without a grounding wire, going all the way to the ground is not the path of least resistance. If you let the coil run without providing any specific place for the secondary coil to ground, the electrical arc will hit the primary coil.

[MRBADASS]

i have a question, how did u ground the secondary coil??

[fun bags]

hook it up to the capiciters

[funwithpower4242]

Actually it's the primary coil (the big spiral cone of copper pipe) that is hooked to the capacitors. The secondary coil - the one around the PVC with lots of turns of the thin copper wire - is best grounded to a rod that is literally pounded into the dirt outside. Otherwise have it go to some flat piece of metal laying on the table on the side or on the ground (look up 'ground plane) or for a small coil it won't hurt to just make sure it does not arc out to the primary coil. Cover with electrical tape, a few layers, to prevent lower arcs from the bottom of the secondary from leaking out. DO NOT connect the secondary to the capacitors - or you may have to spend all that time winding another secondary again!

[FreezeNotice]

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?

[djbaha]

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.

[fun bags]

it is a transformer but dont get A SOLID STATE TRANSFORMER IT WONT WORK

[bigdog19952]

im confused wher does the secondary get attatched?

[kve23]

it doesnt get attached the primary creates some kind of electronic field absorbed by the secondary

[fun bags]

exactly

[adamnsmith]

ya bigdog19952 is right it doesn't say anything about where to connect the secondary. and not much description for the primary )=

[jj.inc]

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.

[adamnsmith]

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

[jj.inc]

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.

[smoothisfast1]

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.

[jj.inc]

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.

[smoothisfast1]

Happy to help

[jj.inc]

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

[jvictor]

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

[creatorborg]

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

[adamnsmith]

ya me too

[adamnsmith]

i wonder if you could make a mini hand held tesla coil with a few 9 volt batterys

[weeven]

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

[Jimmy Proton]

Its a high voltage transformer, probably a NST.

[aweis]

what did you use as a power source?

[jesusdiedforme]

Ohh my goodness, this is so cool!:D i love love love it!

[spark light]

Have you tried tuning it?

[spikeracooba]

can i use more than 1 set of the snapple bottle things

[DevCoder]

yes, but in parallel not in series

[malik98]

can i use 14 awg wire on the secondary