# Building a solid state tesla coil

12 Steps
!This instructable is meant to give detailed instructions on building a solid state tesla coil based off of steve ward's mini sstc schematic.
Ok, here's  the disclaimer.
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I do not hold any responsibility or your use or misuse of this information, in any way. I am not a trained professional and I cannot protect you from the voltages that are part of this project, and any damage this project may cause, wether it be to animal or material. The user assumes all responsibility for the actions they take.
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Well, now that that's over, lets get on to what a tesla coil actually is.
A tesla coil usually has these key components:
*power source
*Switching circuit
*Resonant Capacitor (only for drsstcs, some vttc,s and regular spark gap type coils)
*Primary coil
*Secondary coil
The tesla coil was invented around 1891 by Nikola Tesla. His original intention for the device was to create a wireless energy distribution system. Unfortunately, his design could not send power at even close to reasonable efficiency, as the power was almost all being wasted on corona and arcing. Today, we coilers take this to an advantage.
But what males the tesla coil truly magnificent is the voltage it produces. A typical spark gap type coil takes (usually) the voltage from your wall socket, and steps it up to a couple thousand volts, where it then goes through the switching circuit, through the primary, and is seen on the secondary side as more that 200,000 volts! But how did tesla do this?
The answer is resonance. A resonant circuit, usually consisting of a capacitor and inductor, is much like a slinky. (stretched out) When you give it a push, it bounces back and forth losing momentum with each pass. However, if you keep hitting it every time it comes back, it will start to move really far back and forth at the same speed. (Or frequency) The frequency at which you hit it is it's resonance.
The secondary coil is like our spring. But how do we get voltage from it? Certainly not by hitting it. No, you have to use an oscillating magnetic field from the primary coil to excite it. A normal spark gap type TC would use a resonant capacitor and a spark gap to produce the oscillation, where as our coil (sstc) will use feedback from the coil itself to drive the primary. (using an antenna.)
~~for more info on how a tesla coil works, head on over to Richie Burnett's site or the wiki.
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## Step 1: The overview

Our coil will be a solid state type. The schematic we are using was made by steve ward, and belongs to him. This circuit is a relatively simple circuit as far as tesla coils go, and is a good place to start for a coiler that is new to solid state drive. I will say that you should only attempt this if you are confidant that you can work with mains voltage, as this coil does have direct mains voltage running through part of it.
Unfortunately, I cannot currently put up the steps to wind the secondary coil, but I will put up an intractable as soon as possible. But generally, what you need to do is wind many tight turns of thin magnet wire around a pvc form. Don't make it too tall. A good ratio for height is that the height is about 3 to 5 times the diameter.
Anyway, what you will get out of this coil is approximately 7-8 inch sparks. (Depending on how you set the interrupter) I'll go over this later, but for now, that is what you can expect. Trust me, you'll have fun.
*****EDIT: That mystery symbol appears because instructables cant handle the µ and Ω symbol in pictures. go figure! it works here.
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Samphillips1 says: May 4, 2013. 12:22 PM
What size breadboard did you use?
J-Five says: Mar 17, 2013. 7:17 AM
IT'S ALIVE!!!!!!!
Mvtnns says: Mar 12, 2013. 7:55 AM
Could I use CD4046 instead of 74HC14?
davikrehalt says: Mar 3, 2013. 2:58 PM
Do the common negatives just connect together?
agr00m says: Sep 28, 2012. 10:16 AM
What are the 5.6k and 2.2k resistor for? They're not on the schematic along with the LEDs. Are they just used for the LED's?
physicsjunkie in reply to agr00mOct 7, 2012. 3:16 PM
Your are correct. They are meant to indicate that the regulators are working properly, that is, supplying the correct amount of voltage. You can always double check this with a multimeter.
carnotricecooker says: Mar 2, 2011. 11:30 PM
Is there perhaps a program I could download on my computer that could emulate an oscilloscope?
pnguin9999 in reply to carnotricecookerAug 14, 2012. 12:14 AM
I recommend this scope kit. http://www.instructables.com/id/DPScope-SE-the-simplest-real-oscilloscopelogic-/
I have one and it works very well. The directions for assembly are easy to follow and support is great. I have it hooked up to an older dell laptop. Hooked it up to my Kenwood function generator and measurements are dead on after calibration, which is also easy. I also got the 1x10 probes to expand the range.
pastaking in reply to carnotricecookerSep 6, 2011. 12:51 PM
Yes, but it will kill your soundcard
spark light (author) in reply to carnotricecookerMar 3, 2011. 12:15 AM
While there are oscilloscope programs out there, unless you use an actual oscilloscope device that plugs in to your computer, this project would kill it. I'm not sure if sound cards even have an adequate sample rate, but my best recommendation is to not do anything like that until you have at least a usb oscilloscope, because without isolation, you will damage your computer. It is possible to find decently priced usb oscilloscopes around. I hope to have the time soon to post an intractable info page all about oscilloscopes. Best of luck finding a solution.
sciencetor2 says: May 28, 2012. 6:59 PM
hey, so i noticed your link to the ferrite toroid is sold out, i can probably find one myself, but what are the dimensions or part number? i would hate to get the wrong size.
CamDAX in reply to sciencetor2Jul 19, 2012. 8:09 AM
The ferrite should be big enough to wrap the wires around it several times.
sciencetor2 in reply to CamDAXAug 1, 2012. 7:20 AM
i am aware... but could you link me to the one YOU got?
NCC-1701 says: May 14, 2012. 4:26 PM
I have a couple questions. First, why did you change the dielectric material of C7 and C8 to metalized polyester when the original design calls for polypropylene? Second, why did you change the capacitance of C12 to 680uf instead of leaving it at 420uf ? Do these changes improve the operation of the coil in any way?
sciencetor2 in reply to NCC-1701Jul 19, 2012. 6:38 AM
well, i assume he could not find a 420uf cap, i couldn't, i don't know about the C7 and C8, coilers know that mettalized polyester is no good for tesla coils, at least in a spark gap one, only polypropylene works.
NCC-1701 in reply to sciencetor2Jul 22, 2012. 10:01 AM
after searching through dozens of Steve Ward's projects, I finally found a picture that shows the full model number of the capacitors he used in this project. Here is a site that sells them. http://www.alliedelec.com/search/productdetail.aspx?sku=70103269
sciencetor2 in reply to NCC-1701Aug 1, 2012. 7:20 AM
if you could find the 420uf filter capacitor that would be cool, i cant find anywhere that sells it
CamDAX says: May 26, 2012. 10:54 AM
I built my own version of Steve Ward's coil design with the help of Steve Ward, Joe DiPrima, John DiPrima, and Sam Mcfadden. See coil here http://CamDAX.com/My-Projects.php or http://www.youtube.com/user/modeltrainsfreak
CamDAX in reply to CamDAXJul 19, 2012. 8:04 AM
I added an audio interrupter based on http://kaizerpowerelectronics.dk/tesla-coils/kaizer-sstc-ii/
and a fiber optic link from the interrupters to the coil. It gives me perfect electrical isolation.
sciencetor2 in reply to CamDAXJul 31, 2012. 11:15 AM
can i see your fiber optic setup?
sciencetor2 in reply to CamDAXJul 19, 2012. 6:35 AM
where did you get your stepdown transformer for the power supply to the low voltage side?
CamDAX in reply to sciencetor2Jul 19, 2012. 8:01 AM
I just got like a 12.6CVT 1.0A Step-down Transformer from Digi Key
part #595-1041-ND
sciencetor2 in reply to CamDAXJul 19, 2012. 8:32 AM
and what is the input voltage for that?
CamDAX in reply to sciencetor2Jul 19, 2012. 8:57 AM
On my coil 120VAC goes into the transformer and comes out about ~12VAC. It then goes through a rectifier and a 12V and 5V fixed voltage regulator which can handle a max of 30V.
sciencetor2 in reply to CamDAXJul 19, 2012. 9:05 AM
this is the exact same one you used right?
CamDAX in reply to sciencetor2Jul 19, 2012. 9:12 AM
yes works flawlessly. The only parts I would be careful about are proper heat sinking of the MOSFETs, a good primary coil, and good thermal pads.
sciencetor2 in reply to CamDAXJul 19, 2012. 9:03 AM
yes, ive built that part, i tried to use a radioshack transformer, but i ended up with close to 10 times the listed amps! plenty to fry my board as it turns out :( i have a full set of spares though luckily, so i will grab this one and give it a shot. you are powering it from mains right? (wall socket to the transformer)
CamDAX in reply to sciencetor2Jul 19, 2012. 9:09 AM
yes mains goes directly into the #595-1041-ND transformer.
sciencetor2 in reply to CamDAXJul 23, 2012. 7:28 AM
i would really rather not have to buy a variable dc transformer. but that is looking more and more like the best option :(
sciencetor2 in reply to CamDAXJul 23, 2012. 7:27 AM
k... got the transformer, voltage is still good but i am getting 4 amps, not 1! what is the output voltage/amperage of your wall socket?
CamDAX in reply to sciencetor2Jul 23, 2012. 10:06 AM
Whats the voltage & amperage of my mains or transformer? "On my coil 120VAC goes into the transformer and comes out about ~12VAC. It then goes through a rectifier and a 12V and 5V fixed voltage regulator which can handle a max of 30V."
sciencetor2 in reply to CamDAXJul 23, 2012. 1:11 PM
h8864 says: Feb 8, 2012. 12:50 PM
is this even LEGAL!?
CamDAX in reply to h8864Jul 19, 2012. 8:13 AM
http://lmgtfy.com/?q=Are+Tesla+Coils+Legal
sciencetor2 says: Jul 14, 2012. 6:17 PM
what are the dimensions of the ferrite toroid please?
CamDAX in reply to sciencetor2Jul 19, 2012. 8:07 AM
The ferrite should be big enough to wrap the wires around it several times.
sciencetor2 says: Jul 19, 2012. 6:32 AM
ok, i got the 25v 2A transformer from radio shack that you listed, but i plugged it in and checked it on a multi meter, and i am getting 20A out of it, not 2, even with my variac turned so that the output becomes 12V, i am still getting 6A, plenty of amps to fry everything on my board. What is going on here?
MadScientist101 says: Jun 9, 2011. 9:05 AM
where did you get your perf board/ PCB from, it looks very easy to work with?