Singing Tesla Coil

[hellman100]

My computer speakers broke and I was looking for a replacement.

Found it.

[teslaozone]

Can someone please tell me where i can find instructions to build one. I want to make one for a science fair.

[testardo]

@teslaozone

I posted full instructions on my website.

The PLL I used is obsolete and no longer easily obtainable, but you can redesign the PLL by building your own voltage controlled oscillator and using a square law mixer as the phase detector... (I really need to put together an updated design)..

Have fun!

[awesomelightning]

wo.

[aplle222]

deathly sound

[dumle29]

SELL THEM ON EBAY WITH BUILT IN POWER SUPPLY (if you deside to sell them, can you make a eu one too, to run on 220-230 volts??)

[testardo]

Nope! It's amplitude modulation... There is residual FM as a result of tesla coil resonant frequency shift when the arc is modulated, but that is due to PLL tracking and is not the cause of the audio....

[kakureru]

not a fake radio, its pretty much FM... ie modulate a very high frequency into lower ones u can hear. the HF sustains the spark and the FM makes the audio.

[ronikthop]

this is fake theres a radio in background

[bumsdrums]

how is that even possible

[projectbronco]

Probably the best quality sounding singing tesla I've heard. Many others are distorted and such. Nice job!

[RenanSausen]

nice, i want this song xD

[jt1122]

tim obrien is great i love his stuff and this is also a cool tesla coil very impressive

[Dryvnt2]

Hooooooly sheit

[peguie]

Your descriptive page is great :)

[sydalfox]

are you Belgian ? I see you use a skynet-account

[testardo]

No..I am not a Belgian, but I have been living in Belgium for a couple of years now... Strange little country...de nederlandstaligen et les francophones can never agree on anything! ;-))

[woutervddn]

I live in belgium :p believe me.. politics only get worse every day :p.. who knows, maybe in a couple of months we got two countries, Vlaanderen & Wallon :p

In eather way,, i hope not..

[BenHutchinson1]

Why the fariday cage? If you are in a lab designed for this kind of thing, the equipment you are using should be resistant to EMP.

[testardo]

Well..let's hope I do not need to contend with EMP (electromagnetic pulse; usually associated with nuclear detonations);)

I use the Faraday cage to reduce my exposure to HF fields and to reduce possible RF interference to radio service in the 4-5MHz band and its harmonics.

[BenHutchinson1]

You have a SSTC (not a SGTC) I assume. But aren't the SGTCs the only tesla coils capable of causing RF interference (as a result of their very broad band signal). But an SSTC shouldn't have a problem. And you said to protect yourself from RF fields. But aren't RF fields at only 4 or 5 MHz pretty safe? To get cooked you have to have closer to 1000 MHz and above (like with microwave ovens). And why are you talking about harmonics? Dont SSTC produce pure sine wave RF signals for the HV output?

[testardo]

Any device that generates significant RF power can be a source of interference. I measured significant harmonic content beyond 60MHz (5m wavelength) with this coil using a spectrum analyser...so it is important to be careful to reduce possible radiation.

As for being cooked...it's not likely as long as you don't get too close, but why expose yourself to more "electromagnetic smog"? A glass of water placed in the resonator will absorb significant power.  This might indicate a need for prudence

[BenHutchinson1]

Over 60MHz harmonics? But how? Doesn't your tesla coil put out just a pure sine wave?

[testardo]

How can it just put out a "pure sine wave" when that MOSFET switch is banging it every 200-250ns with a fairly square current pulse? I think you need to do a bit of reading on harmonic generation in switching circuits.. Google "Fourier Series" for a look at periodic nonsinusoidal wave representations... Cheers!

[BenHutchinson1]

But I thought that most SSTCs had filter circuits between the switching transistor and the primary winding of the Tesla Coil.

[testardo]

Yes, the modulator uses PWM to modulate the drain voltage of the RF final PA transistor.

[testardo]

I use "dead-zone" modulation on a TL494 SMPS controller chip. It seems to behave quite linearly for such a simple circuit. See schematic on my PLL Tesla web page.

[testardo]

Yes, you can do this. This method relies on FM to AM conversion in the tesla coil resonator. However, the audio response is generally not very linear. There will be lots of even order intermodulation distortion and harmonic generation that might sound good playing an electric guitar through it, but not so good for reproducing recorded music.

[Szajbave]

Yes like the first on the left side is pin 1 and so on

[testardo]

Yes, the pins are laid out in their physical positions.

I should mention that the linear range of the TL494 modulator is not so great, although you can get some decent results for low levels. I am looking at ways to improve its linearity (Class-D type amplifier, perhaps)

[testardo]

The clock of the TL494 is not what drives the resonator. The VCO (frequency divided by 4)in the PLL chip drives the resonator. The drain of the final power amplifier is modulated by the TL494 circuit.

[testardo]

You got it!!

[testardo]

Oops.. I was a little hasty in responding..

MOSFET _gate_ driven by PLL and drain driven by TL494.

Cheers!

[testardo]

Have a look at the schematic in the technical notes on the web page listed in the description info for this video. I put a bit of effort into this document, so please read it if you want to know a bit about how this circuit works. You will see immediately whether or not I used a GDT.

[Szajbave]

You dont connect the PLL output to the PWM circuit.

The drain voltage of the RF PA transistor is modulated

[jeabo0adhd]

nice sound

[mcsabi20]

it don`t say sssschhhhchhhhssschchhhhhcchhh­h, but it says la-la-laaaa........ :)

[OGMO11]

wait, is it the electricity thats actually "singing"? sweeeeeeeet

[Tschikendebab]

ahahaha singing Coil xD funny man this is crazy xD omfg :P

[phreezerburne]

that is f**king AMAZZZZIIING

[spwim]

how much power does this consume ?

[Auscrawlrule]

That is really clever!! Not only does Tim O'Brien sing well and play a mean guitar, he's also quick for a light of your smoke (with an extension)!!

[thomashuang2007]

Hi would you please tell me what the difference between a plasma Tesla coil and a solid state coil is? Why can a solid state coil only make simple, single-tone sounds but this one can play complicated wave signals? thanx~

[testardo]

These are excellent questions. First, this coil is indeed a "solid state tesla coil". The difference lies in the fact that this is a coil operating in so-called CW mode; like an AM transmitter.

[testardo]

Furthermore, like an AM transmitter, it is driven using a "linear" audio power amplifier on the MOSFET drain. This is much like the method of "plate modulation" of the final RF power amplifier in a tube-based AM transmitter, i.e. modulate the final PA power supply to modulate the RF wave. "Single tone" use interrupters, which are not linear, hence distort the signal.

[mankee1337]

huh? j/k lol

[shinofanatic382]

do u have an ebay store

[mauz12345]

i see you use a Faraday cage for protection. what would happen is anyone gets to close to that Tcoil? can a person be killed by it's hig voltage/high frequency?

[testardo]

No, you are not likely to be killed. However, the RF plasma can inflict severe, deep burns. At full power, this coil generates about 250W in its plasma. Hospital treatment would be required for even momentary contact with the discharge.

[nottafanboy6954]

If the price was right I would certainly buy a printed board and a list of parts. (Never got transfers to work and I hate using markers)

[testardo]

I plan to produce some professionally made PCBs (sending CAM files to a boardhouse) early next year...

Toner transfers are no comparison to the quality you can achieve at a boardhouse...at a price, of course..

[testardo]

If only I didn't have that day job. I could devote myself to building musical tesla coils! ;-)

[noremac7777]

you're the only person i've ever seen to actually bother putting a cage round their coil XD personally i wouldnt't (unless showing it to friends), but kudos to you for safety :P

[testardo]

The cage is for more than just safety. If you had read my description of the design, you would know that its main purpose is to reduce RFI.  These coils can radiate significant power, especially at harmonics of the operating frequency..

[noremac7777]

ahh, cool.

protects both things from the coil, and the coil from things? (electrically/electromagnetica­lly speaking)

[bauerb2]

that is the clearest sounding sstc audio mod i've seen. great work.

[dinosquirrel]

that is the most homegrown tesla I have EVER seen.

[uncivilmatt905]

were do u get those at

[cheaphardwarez]

How much would you charge me to build one of those?

[testardo]

Hi.. I have mixed feelings about selling complete units (could be legal liability issues, etc.) However, if there is interest, I could make the electronics available as a kit. (You wind the coil and provide power supply). I am doing a redesign of parts of the circuit. This should be completed early next year... Cheers!

[hboy007]

wow cool. If people stick to their "I want one", you'll be rich ;)

And perhaps I would want one, too. Unfortunately I have other projects to finish (e.g. the porty flash unit)

[cheaphardwarez]

That is SO AWSOME! and clear too. Can you post a schematic?

[testardo]

The complete design notes are available on my site...

[Guyza1geza]

i dont think tesla speakers will catch on. how much for one 20x the size by the way?

[iosystems]

just google "hill plasmatronics" for more info

[Osegrim]

Is that crumped up aluminium foil?

[testardo]

Yes. The coil requires careful tuning for best performance. The crumpled foil adds just enough capacitance to allow proper feedpoint impedance properties for Class-E operation of the driving power amplifier....

[maskedracoon2]

how much would one of these cost?

and would it require much?(ie would i have to spend $100000 on other parts)

thanks

[98209276]

would a sstc run on just 12v in the primary on a resonant square wave? im talking about a tesla coil not a fly back or ignition commonly associated with the tc . thanks for any reply.

[testardo]

There is no reason why an SSTC could not run on 12V... You just need to design it such that the desired power is achieved with that supply voltage... This means paying attention to primary windings as well as MOSFET series resistance (among other things)...

[lyokofans]

It sound like a normal speaker, but it is done using a telsa coil?

[robertgift]

Fascinating and clear! Thanks, Tard.

Why the mesh screen? To prevent RFI from escaping? Very thoughtful of you. Oh. On dial-up I now see no top cover. The whole thing should be shielded to prevent illegal transmission.

[robertgift]

Now I see your top cover. Thanks.

What do you do about all the O3 produced?

Since so much audio does not match video, does the discharge ever show beat of the music?

[testardo]

Hi Robert. Yes, the mesh screen is to reduce RFI. The coil should be operated in a well ventilated place because of the ozone production. Variations in the discharge size are not easy to see. Perhaps with very low-frequency tones, you may see soemthing.. Otherwise, the discharge looks like a fairly steady purple-white flame..

[MCADJim]

You shoulda had it play AC/DC's "Thunderstruck", for obvious reasons. Anything off Metallica's "Ride the Lightning" would've been good too. :D That's still awesome.

[dizzyparrot]

Thats got to be fake, ive seen tesla coils making basic sounds but there is no way they can produce sounds of that quality and frequency! Im making my own son so I will find out myself!!!

[cranie4]

It sounds like it's distorting at times...but if the level was limited and a crossover applied it would make a killer tweeter

[testardo]

The audio modulator could have a more linear response. (This is something that I would like to improve). But given its simplicity, the sound is pretty good!

[kamuywolf]

That's already been done, they're called electrostatic tweeters.

[Anonymousboy13]

holy shit i dodnt even realize that the sounds was coming from the coil haha. amazing dude. thats pretty kick-ass...

[AACrashBurnAA]

That is real awesome! You've taken the Solid State Tesla Coil one step further! I'll have to get one of these in the future to experiment with. :)

[nhall87]

I call shenanigans

[Renatodonadio]

That's the BEST way of producing sound, without any type of membrane or moving part which can distort sound. Bose and B&O take a look at that! :-D

[Renatodonadio]

I didn't read about plasma tweeters, that means they have already took a look :-D

[hboy007]

this is really nice... maybe the most brilliant sound of all these coils shown here at youtube. So it boils down to an amplitude modulated and amplified HF signal being fed into the primary?

[testardo]

Thanks.. There are two aspects that enhance the sound: the linearity of the modulator and keeping the coil at resonance during shifts in power level. Commercial plasma tweeters exploit similar methods in order to generate their crystal clear sound...

[testardo]

I forgot to mention.. Yes, amplitude modulation of a radio-frequency signal is used to modulate the plasma..

[Darker4308]

Also one has to remember one of these things has to put out a decent amount of ozone and NOx in an air atmosphere so there is probably no way they would ever replace magnetic speaker even with its obvious superior quality.

[Darker4308]

I'm a chemist and I know there are often issues with results. If you get a chance could you do a few more videos with signal disruption ect. to show that you are def. getting this sound out of the speaker and images of the recorder array.

[af7ersh0ck]

wow if these were available to buy as speakers some day that would be SO FREAKING COOL

[hboy007]

there are in fact plasma tweeters available professionally made in ceramic housings and entire ciruity.. just google for it :) but beware.... they cost some money

[Solox21]

I'd love the day these things are mainstream and common, with safety precautions of course, love the music made by singing tesla coils. Maybe that day will come....

[zergminor]

Definitely the best sounding plasma speaker I've ever heard

[greenboy256]

its like an ultimate speaker

[testardo]

I just moved house, so I need to set up my laboratory again before firing up the coil.. When I get things organised, Toccata and Fugue by Bach would definitely be pretty cool to hear....

[samoht1977]

Is it... well, is it right to say that this is an "omni-source speaker"? I mean, sound is not "directional", as waves produced by an ordinary membrane speaker... is somewhat the propagation of sound "spherical"? that would be an interesting argument to discuss when it comes to sound technology...

[Aeryk333]

Yup, we can consider the propagation nearly 'spherical'. The source of the sound is the plasma of the corona discharge on the top wire end, for those who are wondering.

[bbenge2003]

Tim O'brien should see this!

[huskiez16]

whooa!! idk if its the JD im drinking but is the arc playing the music?

[m0ffx]

VERY good job, the only other stuff I've heard sounding this good is plasmasonic. Although the harsh 'electrical' sound of many has its own appeal.

Question: Does the cage influence the sound quality at all, or is it just so you or others don't get too close?

[testardo]

The cage does not affect the sound quality. The main reasons for the cage are, as you mentioned, to not get too close (to prevent accidental burns) as well as to prevent excessive electromagnetic interference from escaping.

[newtonianbarf]

good idea for the cage because in some areas, the government can get pissed off if you modulate your own radio waves without authorization.

[evm2007]

Can you get it to play Beethoven's Symphony Number 5 or Tocatta and Fugue by Bach? Maybe both? ;-).

Seriously could you consider doing that? I'd love to see it play those songs.

Also, it'd probably look a lot cooler if you filmed your tesla coil in the dark.

[testardo]

Thanks!

Modulator linearity is a major factor...as is PLL tracking of resonance as the arc power changes... There are still areas where the system can be improved, but it does work pretty well..

[sklyde0000]

That sounds really nice, considering it's being produced by an arc... i'm impressed

[tesla1961]

FANTASTIC I WIL TRY MAKE 1

[testardo]

FoxPMcCloud. Glad you liked it.. Check the construction notes on my site (URL in video introduction text).

[FoxPMcCloud]

Wow, awesome! How did you do this? I'm definitely interested in creating one of these.

[testardo]

The video does not do it justice, of course.. You don't get that sensation of "sound coming out of nowhere."  In short, the spark is created and modulated by what is in effect an AM transmitter-type system. The modulation of the arc causes it to emit sound...and it not a trivial exercise to make it sound good at a reasonable volume! :)

[mcguyver2010]

How did you come up with this idea?

[testardo]

I confess that it is not my idea. There are other people out there who have developed similar systems either for commercial or experimental purposes. Check out the HV forum link in the video description.

[trinity2118]

This technology was created by a man named Nikola Tesla. Some of it may have been updated since his time. Might I suggest the book "Nikola Tesla: Colorado Springs Notes, 1899-1900" or just search his name of course by search engine.

[Kraehaadru]

i dont get it