Picture of The Plasma Speaker
Are you tired of those old black speakers that only just make sounds? Maybe sound reactive lights are just not enough to impress you? How about a Plasma Speaker?

A plasma speaker is a device that generates an high voltage electrical arc that makes purple light and music! Without any speakers or any moving parts! Sounds too good to be true? Well, you're wrong, the high voltage arc really does 'sing' by vibrating in the air. (Of course, you will need to give the device musical audio for it to work.) And just leave this instructable if you still don't believe me...

And this is something I always wanted to build - I have been dreaming to build one for about 6 months, until Kiteman has greatly boosted my encouragement to build one. (Thanks Kiteman!)

The video of my plasma speaker - early prototype.

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Step 1: The dangers you must know...

Picture of The dangers you must know...
A plasma speaker is no toy...

Health Hazard
Unlike the ordinary speakers, the plasma speaker are dangerous high voltage device, do NOT attempt to build this device unless you know what you are doing... And do NOT even attempt to build one if you have heart problems or weak heart or wearing a pacemaker, because one little shock from this thing can put you out...
I am not responsible for any injuries or deaths caused by this device.

Why should you know all of this? it is because you can ONLY live once, and no more...
If you don't think that you shouldn't build one, just watch movies of it working instead, much better than risking your life to build and operate one.
If you think you are okay to build one without killing your self, then move on to the next step.

Hazard to Electronics
Since the plasma speaker generates high voltages, there is a chance there will be high voltage spikes on the low voltage side of the device, which can get onto the audio line and damage (or destroy) the player. They are some safety features to prevent the spikes damaging the player, but they can fail... So I am not responsible if your player gets damaged, and use cheap players like CD players, if you're rich, you can use expensive players if you want. :-)
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I've built it but I was wondering if you could measure how much current it draws since the power supply that I was using has now passed away ;( RIP Power supply

bizsai1 month ago

This seems little bit risky type of thing.

tcoylejr1 month ago
Tesla would be wicked proud.
TrideepK3 months ago

will a center tap 12-0-12 flyback work?

ChristopherM53 months ago

can i convert a tattoo gun into one of these?

zhangqi19923 months ago

So fantastic! But I am a little confused that, the TL494 has 16 pins, where the second and tenth pins go??? Thanks!

_Totoro_6 months ago

In the schematic it says 47nF 2kV which you corrected to be 47uF 250V, but in the parts list it says 47nF 250V, so is it 47uF or 47nF? Thanks

I used 47nF 2kV.

ObagdadiF4 months ago

Is there anybody still online?

MrElectron1 year ago

I like the design and may attempt something similar sometime, however I did notice one thing in the schematic that would perhaps explain why the mosfet was getting so hot. there is no gate to ground resistor, meaning that the gate goes from 12v to 12v and high impedence when it should be going from high to low. the tl494 has an essentially open emitter output to the mosfet, otherwise I like the idea of using dead time control as modulation, very cool.

What's your solution to the heat problem? Just putting a resistor from gate to ground?

Also, read the datasheet for the tl494, it will show that the gate driving pin is an "open source connected transistor" (google it if you want to) and my previous comments will make sense.

There is probable a pull down resistor in the tl494 or the mosfet gate, thus the circuit works in the first place, however the mosfet is probably switching slowly or partially, due to the high driving impedance on a low impedance gate. If the gate to ground resistor doesn't work, try heat sinking the mosfet along with it. I reccommend a resistor value of around 100-1000 ohms, try 1000 first.

dillonxti10 months ago

the 22k potentiometer controls the duty cycle or the power supplied to the flyback

j0ch3m19882 years ago
Dear Plasmana,

I used my plasmaspeaker for over a year now but I have a problem.
I always used a laptop power supply (90 watt) for the flyback transformer and last week I bought a heavyduty power supply (50 volt/16 amps, 800VA) and now I killed my MOSFET (IRF640). My question is; wich MOSFET can I use for pulling a few hundred watts without killing it. The max the IRF640 took was 26 volts and about 3.80 amps (at 30 volt and 4 amps it blew up). I had a 2SK1082 MOSFET laying arround but that doesnt work very well. I got a very little arc from that one.

Please help me, I really need a MOSFET that can handle much more current/voltage and still give a nice big fat arc from the flyback.


irf3205 it has 110 amps of current handling and 55 volts

there made for car batteries

It's not really about the MOSFET handling current but rather the switching. Get some IRF540's on Ebay for about a dollar a piece and they're 100V, 30A.
Thnx for the reply,
I got 2 irfb20n50k's now. 500V 20A and I guess they can handle 280 watt at 25 degrees celcius. Atleast that is what I read in the datasheet. :) This MOSFET works great at 35V and 3.4A but I don't want to blow it up, haha. Got a 50V 16A (800VA) toroidal transformer attached to it with a variac and a 100V 22000uF capacitor.
This MOSFET don't get that hot with a CPU cooler attached to it and I got a pretty long and loud arc. But I guess the MOSFET can handle even more! :)
Here is a movie of my power supply and plasma speaker (only on 25V) :p
Sweet setup and spark! =)
When ever I bother myself to make another of these I think I'm gonna add a 148watt Peltier cooler. Might help those poor MOSFETS from dying? =)
good idea about using a cooler but one side of them gets really hot so your just moving the problem. im probably wrong. will the cool side being heated by the MOSFET cancel out the other side from overheating.
Hey Crimson-Deity,
Here is just another video of my plasma speaker at 34 volt this time.
The arc is now longer and louder! :)
I will probably crank the voltage up some more in the near future, but I really hope I don't pop the MOSFET. :P
Thnx, I still need to build the variac, bridge rectifier and capacitor in a box :)
And maybe I will build a volt and amp meter in it aswell. Looks alot better then a separate volt and amp meter if u ask me! :)
I bought this stuff a week ago so that's why it lays all over the floor. :p

About dying of MOSFETS, I guess if u stay in the voltage, amps and watt range of what they can handle, u will be fine and keep them cool as possible. :)
cheshirecorn12 months ago

Thats helpful


Alright. So i built this with blind luck (Many of the projects i try to replicate fail in some way shape or form...) And well, i was surprised it actually worked! The shock was electrifying!! (No pun intended) But alas, i do have an issue.
When i powered it on, it worked at an extremely high frequency, but even worse, it blew out my power supply! Now, this was an older power supply i scavanged from a satellite dish box or something (It had +5 +12 +22 and +30 which was much better than my ATX, considering it only goes up to +12 volts...) This being the first time trying it out, i thought maybe it was a bad power supply that was already bad, i just finished it off. I was wrong. I pulled out my 12 volt SLA battery, to use that instead. Not sure if it was the power supply's fault last time, i decided to only turn it on for a few seconds. The cable leading to the board got really hot, the battery got warm (Uh oh...) and the mosftet got hot to the touch; Only in a matter of seconds! Thankfully, the battery is still ok at the time of writing, but what would be the cause of such an issue? I am thinking it may be shorting somewhere, but looking with my multimeter i dont seem to find any errors. Only the mosfet and the power cables get extremely warm as far as i know. Any ideas? Great 'able BTW, was very easy to follow and understand.
UPDATE: Alright, so i swapped out all the wires with 14 gauge wire, which by the way is complete overkill, and tried using an ATX power supply. The ATX didn't even try powering it, being way too high of a current for it to do anything...
Any idea why this is happening?!
ivver1 year ago
Is it possible to somehow use plasma globe (ball) as plasma speaker (ofc, when you take out the globe)? I have problem with flyback trasformer, I can't get it working somehow.. But, I have broken plasma ball so I have driver for ball which I don't need..
Thanx in advice.
123456dang1 year ago
And the flyback transformer I can see it has a lot of leg so which one can I solder the coils in? And one more that can I replace the coils with the spark plug in the car?
123456dang1 year ago
I read it and I wondering that what can I do to protect my phone which will have a chance be strike from tesla coils? help me please!
Thats incredibly good
For those of you interested in building a plasma speaker, there's a nice plasma speaker kit offered by excelphysics that includes everything you need to build one!
I replace the MOSFEt with a IRFP4004PBF 40V 350A. Now it doesn't even get warm and the spark i fat. Just a heads-up.
ivver2 years ago
Could you put this circuit to the Tesla coil? I mean, will it be the same results when you put flyback and Tesla coil?
Itchago2 years ago
Why do you have a separate power supply for the flyback? Isnt the power comming from the circuit? What i can see from the schematic it would be going to the Mosfet? Also, is it possible to use a Ignition coil instead of a Flyback?
Wait so do you need to use a battery? Will a power supply like this work for both the flyback and circuit simultaneously? If it's not steady enough I have a 12v VRM and some caps. About how much current does this use?
France942 years ago
Hi, i didn't get how to wire the ground, have i to connect the two negatives of both battery and power supply together or is it somehow different?
please help me, 'cause i've built all the rest right and it doesn't work.
PS is there any difference in using a "non solid core copper wire" for the windings?
jwoo20232 years ago
The Plasma in the video looks like its dancing and singing to the song! :P
hey what about if a 5 watt amp is placed before the flyback
hey what about if a 5 watt amp is placed before the flyback
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