Building a solid state tesla coil

!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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jewelzc43 months ago
Thank you for the instructable.
jasshopper3 months ago

could i replace the power supply part with an SMPS from a PC, by using the blue(-12v) wire from it for 12v and white(-5v) as 5v?

Ey dude! Great instructable! One question: why did you leave this apart?

Hey great instructable! One question: If the voltage supply schematic displays a 20V1A transformer why did you use a 25V2A ??? Is there any technical reason or did you just happen to have of of those laying around? Thanks

dillonxti7 months ago

will this work with a bipolar half bridge

Jan_Henrik7 months ago

Very cool project!

erikdiy1 year ago
First of all, GREAT instructable!

Second, I have a huge bug that I can't fix.

I copied the schematic and made a PCB layout. I solder everything, and made sure the gate transformer was connected correctly.
Now, the coil won't produce spark. I use a step-down transformer to step the voltage down to 110 (220-110), and I also put a variable SSR (solid state resistor) to make a cheap variac. The major problem tho, is that the MOSFETS are quickly overheating and shutting down, making the transformer buzz. The odd part is that the MOSFETS are starting to heat up at only 30v. The coil at this point is barely making a park.
The coil setup is 4T primary, and secondary 0.35 mm x 1000t on a 75mm acrylic tube.

Any help would be greatly appreciate!
8 months ago

I have the exact same problem. Any help from the high-voltage community? Or, if you've figured it out, what was the problem? Thanks ahead of time.

sciencetor22 years ago
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.
9 months ago

I believe I used this from Mouser electronics. Mouser part number:875-28B0999-000. But I could only get 15 turns, still worked fine. It's dimensions are 1" O.D. .61" I.D. and .5" length.

2 years ago
The ferrite should be big enough to wrap the wires around it several times.
2 years ago
i am aware... but could you link me to the one YOU got?
jasshopper1 year ago
and isn't it possible to play music with this? if so how do i do it?
9 months ago

Yes it is. I used this circuit I found for audio. http://wiki.xtronics.com/index.php/File:555c.png

LivinLikeLarry10 months ago

Hello. In the section about the interrupter, what are the potentiometers for and how do I determine what to set the to? All help is greatly appreciated.

9 months ago

They determine the on and off time of the interrupter. If you have an oscilloscope you can build the interrupter circuit and see how they affect the waveform. Just set them somewhere in the middle. Doesn't really matter it will work no matter how they are set. If you get your coil running you can adjust them while its on and you will see and definitely hear the adjustments you make. When I first made this coil I actually used a circuit from the 555 data sheet to make a 50% duty cycle timer as the interrupter.

Thanks for posting this spark light. My first tesla coil. It was definitely a learning experience, and exciting to get that first spark. A note to anyone trying this; if you have a problem along the way read the comments, google and search youtube. A few of my questions were answered that way. I started this project back in November 2013. I have since altered a few things like making a home built torroid for the top (instead of an oil filter wrench in the first photo) and figuring out how to make it play music. I plan on making an instructable as well sometime soon.

leviterande1 year ago
Imm looking forward to follow this clear and clean tutorial. I am wondering one thing though:
How can two switching on/off mosfets produce AC, I have read a lot but cant get how that is possible, that is physically impossible from one way conducting mosfets...
9 months ago
it doesn't create a.c. but it does start a resonance in the tesla coil, the kHz is just right and it goes back and forth in the secondary coil making thousands of volts with only 2 coils, instead of going one way it comes back and forth
cvaughn39 months ago
and what about the secondary? does that have to be in resonance with the circuits or primary or both? or does it keep itself resonant because of self tuning because of the antenna
cvaughn39 months ago
hey, I have a question, you put this together in sort of a modular way, but did you put it all together on a board?
coolkids10 months ago

hey my mains output is 220v ac so what can i change ?

should i just step it down to 120 v and continue?

i have a question....i finally got my secondary and prinary coils in resonance and the freq is 750hz how can i test for the freq range...what pins of the cd4046
i have a question....i finally got my secondary and prinary coils in resonance and the freq is 750hz how can i test for the freq range...what pins of the cd4046
echong410 months ago

Is it possible not to use a variac? Can't get it where I live and shipping is so expensive! Is there an alternative or can I just leave it out completely?

why is my half bridge not working ?...i coppied your design exactly but instead i used irfp250s.and im not getting anything from my half bridge and i tried connecting the two mosfets oppositely but to no avale . plzzzzz helpppp anyoneee.

11 months ago

Check with the irfp250's datasheet, are you sure that you wired it correctly? The first pin is the gate, the second the source and the third the drain. 1=LEFT,2=UP,3=DOWN... that's weirdly how I remember it. Check that you are getting the proper voltage to the pins on the chips. ETC. If you need more help email me at "oconnorct1@g(MA)il(dawt)calm"... haha, don't want no spam.

leviterande1 year ago
HI, Can I run this SSTC in CW mode, as well as Interrupter mode? or once the interrupter is in the circuit, all I got is interruption control?
1 year ago
For CW, cut power to the interrupter and apply 12V to where the interrupter connects to the UCCs. You can use a DPDT switch for this.
carnotricecooker3 years ago
Is there perhaps a program I could download on my computer that could emulate an oscilloscope?
1 year ago
Better off buying a cheap analog oscilloscope.
2 years ago
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.
3 years ago
Yes, but it will kill your soundcard
spark light (author)  carnotricecooker3 years ago
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.
techno guy1 year ago
can this one play music by switching the interruptor for a musical one
JasjotSingh1 year ago
NICE WORK
jasshopper1 year ago
could i use irfp250 instead of irfp260
Samphillips11 year ago
What size breadboard did you use?
J-Five1 year ago
IT'S ALIVE!!!!!!!
Mvtnns1 year ago
Could I use CD4046 instead of 74HC14?
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