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Solid State Tesla Coil

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A solid state Tesla coil is one of the kinds of Tesla coils available. It has several advantages over the more common spark gap tesla coil. They are less louder than conventional Tesla coils, yet they can still achieve a respectable output. They can also be made to play music through its spark, which is a cool effect. Examples of this trick can be seen by searching for musical tesla coil or singing tesla coil. They are also more friendly to nearby electronic apparatus, although caution should still be applied.

In the following instructable, I will show you how to make a solid state Tesla coil, as well as several helpful tips and hints that will come handy during its construction. I take no credit for the original design, which is Steve Ward's, with some small modifications "here and there."

While fiddling with the antenna, I accidentally burnt both of the Mosfets, so bear in mind this design is far from perfect. I'm still posting the instructable, as some of the techniques I used may be interesting to some. Try at your own risks. Results may vary.

If you like this instructable, please rate it and vote my instructable for the contest.
 
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Do you know how many volts the output of this tesla is? As in how many volts can its magnetic field power? You can test this by putting light bulbs in it and seeing the highest on it can power.
Michael Chen (author)  makershaker0515 days ago

You cannot test a voltage on a Tesla coil by putting light bulbs; I recommend you to read clearly the difference between voltage, current, and power to see why. Most household light bulbs (not counting cars) operate at 120V; the Tesla will light them all to varying degrees.

At these voltages, unless you have a (extremely expensive) high voltage ac meter, acquiring a precise measurement is unlikely. A (very vague guess) would be between 100kv and 500 kv.

Sorry I don't know why it sent three
Do you know how many volts the output of this tesla is? As in how many volts can its magnetic field power? You can test this by putting light bulbs in it and seeing the highest on it can power.
Do you know how many volts the output of this tesla is? As in how many volts can its magnetic field power? You can test this by putting light bulbs in it and seeing the highest on it can power.
lam3 months ago
Hi Chen..
Could you tell me how wattage or ampere (240V or (120V) x I?? = watts) when your tesla coilworking.Thank you so much
jasshopper9 months ago
could i use irfp460 and increase the input voltage to about 220v? and what is the resistance of R4 and R3?
GeneralTarquin10 months ago
Could I get a nice list of materials? I'm looking to go somewhere and buy what I need... And I'd prefer to know what I need to get thanks
Agreed
JHSTUBA1 year ago
I have a 4.25 OD PVC pipe, should I be fine? I also was wondering what length I should make the secondary winding, because you have yours as 17 inches, and Steve's is only 10
Michael Chen (author)  JHSTUBA1 year ago
Actually, tesla coils are not really that sensitive to coil specifications, as long as the aspect ratio is still close enough. Your pvc pipe is just fine.


Regarding the length, either one will work. In fact, steve ward's sstc 1 (which has a similar topology) has a 14" secondary; his sstc2 has a 18" (albeit this one uses a full bridge instead of a half bridge). Anything about this range should work fine.
Adrenal1ne1 year ago
I have been trying to make an Audio Modulated SSTC for a while now, and I have found that your Ible has been the most helpful yet. So on step 11, where you say this SSTC could become audio modulated by changing the interrupter to an audio one, what exactly does that mean? Circuit diagrams are definitely not my thing, and I have not been able to find a sophomoric explanation of an Audio Interrupter or MIDI Microcontroller. I hope someone can help me!
Michael Chen (author)  Adrenal1ne1 year ago
Well, actually, this tesla coil is not audio modulated.There is nothing on the schematic that performs audio modulation.

However, if you were to replace the smaller schematic (which is the interrupter's schematic) with one designed for audio modulation... well, you would have audio. There are several diagrams over the net. However, I would recommend you to only go for audio modulation after you get the basic setup running.
Would I be able to power this tesla coil with 240v without using a power converter or similar?
Michael Chen (author)  tesladude1231 year ago
While yes (with some minor modifications), I would recommend using one f]designed for 240v.This design is made for 240v:

http://kaizerpowerelectronics.dk/tesla-coils/kaizer-sstc-i/

If you still want to use my design or Steve Wards, there are some changes that need to be done, mainly replacing the mosfets with higher voltage equivalents.
Michael Chen (author)  Michael Chen1 year ago
*designed
I have decided to use your design because of the lack of components (mainly the ucc chips) I will most likely use FDH44N50 mosfets. One question, on the schematic all of the capacitors are eletrolithic but on steve wards schematic they are not, the capacitor that is 470uf, is that electrolytic and what voltage rating is it?
Thanks.
Michael Chen (author)  tesladude1231 year ago
Sure, those Mosfets are perfect. Regarding the capacitors, I kinda just used a single image for all of them, but not all of them have to be electrolytic.

     Usually, >1uf are electrolytic; <1 uF are not. The .68uF capacitors have to be non-electrolytic. Yes, the UCC chips are not that common. In fact, I made this design because I couldn't find them. However, this design does not use an isolation transformer as other designs.

     The disadvantage of this is that if you make a mistake, all the chips will blow up instead of just the mosfets. I see no reason why this wouldn't work at 240v, as long as you use the Mosfets you showed me, and the capacitors you use for the bridge are rated at at least 400v (240v * sqrt(2) + clearance). C5 should also be rated 400v; and for D3 you must use a diode that can withstand that voltage; UF4004 to UF 4007 will work. Don't use UF4001-UF4003, as their reverse voltage is not enough for 240.

I'll double check the schematic later to make sure everythin else will tolerate 240v, but so far that is all I can think of that has to be changed.

Curious fact: my design is just steve ward's design with this stuck in place of the UCC; if you look at the reference design you'll see my design is a virtual copy of that.
Ok, thanks for your quick reply. Another question though, the 470uf capacitor on the half bridge is that non-electrolytic, because I'm thinking it would be hard to get a capacitor that size and voltage for ac current.
Thanks.
Michael Chen (author)  tesladude1231 year ago
It is electrolytic (I seriously doubt they make non electrolytic 470uf caps). On the halfbridge section, the ones that are not electrolytic are the two .68uF capacitors. For every other capactor, just use whatever you find, either or. Just make sure that whatever you use on the halfbridge area can take at least 400v.
Thanks you are a great help, ill get back to you soon when i start building this tesla coil. P.S im using a auido interruptor seen here: http://www.megavolts.nl/en/projecten/tesla-spoelen/153-audio-modulated-solid-state-teslacoil-v2
pranjal121 year ago
Hey can you provide clarification on the parts needed.As he schematic is not clearly visible. thnx
This project can cost u approx 600 to 700 $(INR 33000 to 38000). I recommend u to take a look at this 'ible http://www.instructables.com/id/How-to-build-a-Tesla-Coil/
Michael Chen (author)  panny19961 year ago
Actually, your estimate is way off. I did mine with less than 100, although I did scrounge some pieces.

Besides, that tesla coil is a spark gap tesla coil; which uses a primary with 15 kv through bare coper wire. That type of tesla coil is potentially more dangerous than mine, as mine's primary uses 170 v in an insulated wire.

Besides, that one is potentially expensive. Right now, the one you linked uses leyden jar capacitors. Although it works, it is nowhere near its full potential. A commercial high voltage capacitor is expensive, so at the end, they end up kinda even.

The spark gap coil may be a tiny bit cheaper, but I don't consider that is worth the safety risks.
i get it that but the thing is, the guy to which i sent the message lives in India. I too live in India where the material required actually is expensive comparing to the costs in US.

Second thing is that the guy prefered to have better explanation, so... i got down to search and gave a ible that appeared to me bit more explanative.

So, don't misunderstand me dude.
The first answer i gave was a rough pricing, if i consider yours as 600, its relatively simple(according to you) that the other one is about a 1000$(For guys in India).
So, mix the answer and sorry if i hurted you.
Michael Chen (author)  panny19961 year ago
Sure, no problem; I understand not everything can be gotten anywhere at a fair price. For instance, my design is based on Steve Ward's design, but I had to make several modifications to the design in order to make it with what I could obtain cheaply in Panama.

Similarly, you can surely make a sstc on India, but to make it cheaply you would have to alter the design based on what you can obtain; a non trivial process which requires electronics knowledge. The other design (spark gap tesla coil) is way easier to modify and uses parts that are easier to obtain.

If you happen to make one, just make sure to really step back when they are on. Although the the streamers from the secondary shouldn't be lethal, if a streamer touches the primary and a person simultaneously...well..don't touch it.
thanks for understanding, i took a look at your other projects, i liked your PSP speaker mod.
By the way where do you stay in USA
Michael Chen (author)  pranjal121 year ago
Actually, the schematic should be clear enough, but you need to open the image and view as original, by clicking on the image, then again on the zoomed one.

For convenience, here is a link: http://www.instructables.com/file/FBV4NJZGYDLQG6P/?size=ORIGINAL

However, as I point multiple times during the instructable, I recommend you to use Steve Ward's SSTC5 design if possible. I made my own because I couldn't find all the parts in Panama, and international shipping sucks. Due to his design using a gate drive transformer it is much more robust.


Here is a link to Steve Ward's schematic:
http://www.stevehv.4hv.org/SSTC5/miniSSTCfnlsch.JPG

If you have any question about whichever of the two you decide to use, feel free to ask. Just specify by which design you are going.
Oh i see you have already given a better schematic, so sorry once again.
hi. i built this but followed steve ward's design. i have a problem i dont know if you can help me with but ill ask anyways. i plug in my low voltage and my LED's light up and i check it out with my multimeter and everything there is fine. when i plug my AC in to the high voltage side where the fets are (mains>variac>AC terminal>high voltage bridge rectifier etc..) the first thing that happened when i slowly cranked up the dial on the variac, the fise in my variac blew at about 50V. i went out and bought more fuses, of course, and tried again. this time when i hook everything up, the variac hums/buzzes and starts smoking!! and this happens at 1V!!!! literally move the dial off 0 and it justs humming and smoking. so of course i checked the variac out on some other equipment to make sure it was busted (this is a BRAND new 5amp 500V variac) and the variac works just fine. so i am going back over my Gate drive components to make sure i have everything in the proper place and so far i cannot find anything wrong.. do you have ANY idea why this is happening?? any advice i would greatly appreciate
Michael Chen (author)  physicsjunkie1 year ago
Sure, what is probably happening is that the top and bottom mosfets are both turning on at the same time. The real question is why. Without photos of your setup;helping you will be hard. Please take close up photos of the circuitry and send them to my email.

**note to self: send email by PM next time** :)

In addition, I recommend you to register to "www.4hv.org". There are lots of friendly people on that forum. The registration process is kinda complicated though, so read the registration form closely.
Michael Chen (author)  physicsjunkie1 year ago
(removed by author or community request)
okay thanks i will register with them. I am emailing you photos now. thanks for you help this is really nice of you
JHSTUBA1 year ago
This looks amazing! I'm definitely going to build is :)
One question though...
How would you modify this to play audio? Would I just replace the antenna with a mono audio signal and connect the ground to the common negative, or would there be some additional circuitry that would be required? I don't know if I missed it, but there seemed to be some information missing.
Thanks for your help and a great instructable!
Michael Chen (author)  JHSTUBA1 year ago
Nope, there would be some additional circuitry required (mainly, a modulator). If there is anything unclear, just ask so.

I truly recommend you to google "Steve Ward SSTC5" and read his design on tesla coils; after all, I based my design on his. He also does a better job than me explaining the electronic aspect.
Okay, after looking at Steve Ward's site (I read almost all of his site), I still have a few questions. I found an audio interrupter schematic (http://www.megavolts.nl/images/stories/projecten/AMSSTCV2/files/Teslacoil%20audio%20modulator%20(interrupter)%20circuit.pdf), and it supplies the interrupt signal through an optocoupler. To connect the signal, would I connect the coupler between the 5V line and where the antenna is? Would I need to remove the capacitor on the antenna, and will I need an antenna at all?
Thanks again for your help!

Michael Chen (author)  JHSTUBA1 year ago
Nope, the antenna stays the same. If you use Steve Ward´s SSTC5 driver, it would go to pin 3 of the UCC chips (eliminating the 555).

If you use my driver, it would go to the tag that says "from interrupter"; again eliminating the 555 & associated parts from the second image.

If you are going to attempt to build it audio modulated, I'd say build it first as shown in Steve Ward´s page but with the 555 in a separate board (to test it without audio first); then change it for the modulator you posted.

By the way, have you dealt with high voltage / electronics before?
To some extent, and my father who will be helping me with this is an electrical engineer.
But the problem is that according to Steve, the antenna is supposed to create the frequency and drown out the signal from the 555, so wouldnt that just make the coil lock on one frequency?
Michael Chen (author)  JHSTUBA1 year ago
Well, yes and no. If you look at the first diagram (which is deprecated, the last one is better); there are two 555´s. The leftmost one is the one that is overpowered by the antenna.

The one on the bottom is the one you would replace by that audio modulator; which performs a different function. The design on the bottom of his page (the final one) only has one 555, as he managed to do without the startup 555.
Okay, thanks, I found all my parts online, and there's a magnet wire supplier a few miles from my house, so I can get enameled wire for my secondary.
My last question is, what is the diameter of the flexible duct you are using in the toroid? From the photo I would guess 3 inches, but I want to make sure before I buy it.
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