A reliable plasma speaker

I've seen multiple designs for a plasma speaker online, and quite frankly most of them suck. Some problems I noticed were constantly blowing up MOSFETs, distorted audio, excessive heating of the MOSFET(s) etc.

So, In this instructable I'll show you how to build the speaker that's on my website. Properly heat-sinked it'll be able to run continuously; I have run mine for a length of about 6 hours with no problems.

Step 1: Gather the parts

You'll need some parts for this speaker, not too many but some.
You'll need:

Components:
4x  UF4007 diodes
4x 12 volt zener diodes
2x  IRFP250 mosfets. You can also use some better fets, the lower the Rds On the better. Just make sure they can handle at least 200V, flybacks make some nasty back EMF.
1x  SG3525 IC
1x LM7812
2x  22 ohm resistors
1x 2.2k resistor
1x 10k pot
2x 0.1uF (104) capacitors
1x 3.3nF (332) capacitor
1x 1uF (105) MKP capacitor
1x 2.2uF electrolytic capacitor
2x 10,000uF electrolytic capacitors If you use 40v 8000uF caps instead you can apply 36V and make the arc even bigger and louder. Just make sure to replace the 7812 with a 7815 or a 7818.

Other components:
A flyback transformer. You can get these out of old computer monitors, TVs etc.

A ferrite toroid. These may be inside computer monitors, but if you can't find one get it here.

Some 18ga wire.
Some 24 ga wire, the wire from inside of a telephone cable works great.

2 heat sinks, you can get them from a computer monitor. You'll need to use your scavenging abilities here.  If you use 1 heat sink make sure you use some insulating pads.

Thermal goop.

Comments

[SirLordCrazyFish]

Thanks, I just made my first plasma speaker and it worked. I have looked at others, but none have been this easy to build. So once again thanks. Keep doing what your doing.

[Itchago]

Would it be possible to swap out the flyback to a ignition coil?

[grenadier]

Nope; you'd just inductively heat the coil's core at these frequencies.

[seabeepirate]

Alright, I really like this project but it seems more than a little over my head still. My question is, can I use a 555 type PWM and attach the portion of your circuit from the GDT to the Flyback, to the output of the 555 PWM?

[grenadier]

Should be possible, yes. But the 555 timer isn't push-pull, so you might have issues driving the transformer.

[grenadier]

(removed by author or community request)

[seabeepirate]

OK. What voltage and current levels will you see at the input of the GDT?

[seabeepirate]

The reason I ask is because I'm considering attempting an Arduino project and I want to be sure the Arduino can power the GDT, or if necessary I'll build go-between to amp up the Arduino output.

[grenadier]

Yeah you're going to need an amplifier for that one. Keep in mind though, an arduino isn't going to be able to produce a 50kHz frequency modulated signal...

[seabeepirate]

I understand, but I think the signal it can give will be high enough that it won't be horribly annoying. I'm sort of trying to virtualize part of the circuit with the Arduino until I get it working. It's really more of a learning tool for me, if I can figure out how to code it then I should be able to transpose that code into a physical circuit and replace the Arduino.

I think I can build a circuit to invert half the pulse signal of the Arduino or 555. I need to load it into my simulator and try it.

Thanks for all your help, If I get it all worked out I'll try to post a video or maybe an instructable of my own.

[mmcnater]

I have a 30V/5A DC power supply. Will that work, or does it need 10 amps [at least?]

[billgeo]

Hello,

Great design! I'll give it a try!
I realy like the gate driving toroid idea!

About the MOSFETs now, I am trying to find one with low on resistance
but I think the turn-on delay and rise time will be nice to be low as well.

What do you think?

Also in a 36V setup (3 x 12V battaries) would a simple 7815 sufice?
What do you calculate the voltage drop to be there, and the current as well?

Thank you in advance!
Again, nice work!

[billgeo]

I think the rise time of the MOSFET should allow for the PWM frequency.
What frequency did you find works best?

Also what do you suppose is the max current through each MOSFET?
Would 20A continuous be enough?
I am looking at the IRFP360...

[bauerm6]

What do the zeners do? I've got this set up with a 36v power supply and I keep shorting them.

[grenadier]

Protect the gates from too much voltage. In your case they're either; A) in backwards, or B) Getting hot because something else is terribly wrong.

[jmoreira2]

Hey man, I have a question abou the zener, how is it polarized? I cant tell from this diagram and cant access the schematics.

[deaks]

try the diagram on this page: http://forum.allaboutcircuits.com/showthread.php?t=51525

[AznINVazN]

dude, that circuit diagram is so difficult to understand... I'd rather traditional

[grenadier]

Read the text again

[mdbarrett]

I agree with AznINVazN - that diagram won't help anyone. One can read the text 10 times over but it won't change the fact that the link you provided also doesn't work.

[deaks]

you can view a page with his diagram on it at: http://forum.allaboutcircuits.com/showthread.php?t=51525

[deaks]

you can view a page with his diagram on it at: http://forum.allaboutcircuits.com/showthread.php?t=51525

[hginter]

Ty for the quick answer, but I also can't find 8000uF/40V capacitors, will 8200uF/50V work with 36v?
Also, I'm trying to find some higher quality MOSFETS, by "lower the RDS" you mean lower closing resistance?
AND is this ok as the voltage reglurator when using 8200uF caps?
http://ee.farnell.com/fairchild-semiconductor/lm7815ct/ic-v-reg-fixed-15v/dp/1467366

[grenadier]

50V is the maximum voltage the capacitors can withstand; running them at 36V will be fine. The regulator will need a big heatsink though if you choose to run the circuit at 36V

[hginter]

Hey, I can't find a MKP 1uF capacitor with 63 VDC and 25 VAC.
Do the VDC and VAC matter? Does the material matter?

[grenadier]

So long as it's rated at >50WVDC it'll work.

[luig]

if i try to build the 36V version can i use 50v caps instead of 40v caps and do you mean you need a total of 16000uF instead of 20000uf in the 24v version.

[jensenr30]

What does this piece do for the circuit? what is it usually used for?

[-max-]

to get the mosfets out of phase (so one gets an inveted signal, and what will happen is when one mosfet is on, the other of off, vise versa,) that needs to be done so the two fets drive the primary and not short themselves out when the signal is high.

[grenadier]

What piece do you speak of?

[Whatnot]

If you go to step 2 'making the GDT' you'll see that tyyu21's comment is the only one there, so I guess he means that.
Instructables just bunches all comments together on page one too causing the confusion.

[grenadier]

Ahh, OK.

Its purpose is to isolate the mosfets from the IC.

[tank1357]

How did you arrive on 14+ turns?

[jensenr30]

How does the GDT isolate the mosfets from the IC?

[grenadier]

I just did what worked best.

[Minifig666]

It's a transformer. The IC gives out high(ish) frequency square waves and they are induced from the coil on the IC to the coils going to the MOSFETs. Because there is no physical connection they are said to be isolated.

[jensenr30]

thankyou!
XD

[carldong]

Hi, I made this circuit as two parts: one with SG3525 and two totem poles for generating square waves, and another for half bridge. However, the half bridge dowsn't work, and I am wondering will a low quality winding on GDT will stop it from working? I've checked the waveforms on both MOSfets, they are right and reversed. But I cannot get any output from the board if I increase the frequency to about 4kHz. Anyone with any ideas?

[playpep]

I would love to build a set of these for use these at the golf course.{lots of rich kids who have some pricy toys, and i need some leverage} i am doing some research and want to know how loud you can make these. Great illustration of the circuit and please let me know. I want to get my information from someone who has experience in their production.

[Top-Dog]

Does anyone know how to make the arc sound/look bigger? Could you just power the circuit with a higher voltage (and power the ic seperatly off a lower voltage)? Also, if only 2 large caps are needed why does the picture show what looks like 10 large electrolytic capacitors?

Thanks

[Blaneparker]

Put you cursor over the compactors and it will tell you why.

[Blaneparker]

What would happen if you touched only one of the leads? Or if you put a finger between the two leads?

[spyrusthevirus]

how loud is this thing?
how can it get louder? From what I understand, a biger arc will be needed for more sound, and higher voltages will be needed for a bigger arc. How big is this "bigger"? Is pluging the whole thing on the wall safe enough or are we risking frying something? :P
The batteries you are suggesting, for how much time can they power the speaker before they empty? Is there any solution that is renewable in the sense that it can be used over and over again without buying new ones-even with some recharging (if using the houses power supply is out of the question).
For the flyback, I don't have anything old available in order to scavenge. For what features should I look to get good performance?
In the videos I notice there is some noise from the arc jumping around. Would a fatter cable or a "big" (say, .5cm diameter) electrode help reduce that?
And to end the torrent of questions, about how much power does the whole thing draw? I'm guessing it's quite energy hungry.

Neat idea.

[Blacklight [HUN]]

I need a little bit of help :S
I built the circuit and ran it from a laptop charger at 12 V. It worked fine, until I increased the voltage to 24 V. The circuit simply stopped working. I checked every soldering and wire on the board, and all of them are fine. What could be wrong?
There is no voltage between the wires which go from the board to the flyback.
PS: I used exactly the same parts listed in step 1.

[Alex1M6]

Hi, I just made this but the chip gets very hot but I connected everything up correctly.

any ideas?

[kovama1]

Hi I solved this problem with changing toroid. Before change i used yelow from PC power supply, but chip got realy hot. Then I found one black and chip is cold :-) This is my speaker but stability of arc is horrible I thing that could be in 10k pot I'm going to buy better one. http://www.youtube.com/watch?v=Us7lu6PorJk 
(P.S. sorry my english :-))

[Alex1M6]

Hi, I managed to solve it too by also swapping out the ferrite core I was using but I also went one step further and used a totem pole stage between the chip and GDT. The chip stays cool now and the MOSFET's also stay cooler. I have found using a 50k in series with a 10k pot works much better as it allows for a much wider range of frequency's to be selected because of the 50k but the 10k still allows you to make small adjustments as the 50k on its own can be quite sensitive.

Here is mine

Alex.

[kovama1]

Could you please draw it in this schem? http://teravolt.org/Plasma_Speaker_2_files/schem.png ? :-)

Thanks

[Alex1M6]

Its not my website so I can't.

[kovama1]

Why not use operational amplifier instead of the toroid? It could work? :-)

[Alex1M6]

No idea, never used one before.

[Blacklight [HUN]]

Are any MOSFETs good if they can handle 200V and at least 20A?

[adeebm]

I just built the circuit on my breadboard for the 4th time, and the strangest thing is happening. One or more of the components seems to be resonating and playing the song. To clarify, I have the full circuit build on the breadboard, hooked up to audio. When I connect the flyback, I get almost nonexistant sparks. With OR without the flyback, one or more components on the breadboard is resonating and can literally hear the song being played with no spark. The sound seems to be coming from the MOSFET side, but I can't be sure. What's going on here? Since the flyback isn't hooked up, there can only be 12v running through the board, not enough to arc, so how can there be sound?

[grenadier]

I'm just as stumped as you are.

[adeebm]

If I remove the mosfets from the circuit and keep everything else in place, the audio starts to come from the ferrite toroid. When I place the mosfets back in, I'm not sure where the sound comes from, but it gets louder. Also, when I pull one of the cap leads out and place it back, it sparks makes sound. I wonder if the breadboard or something internal is sparking. Maybe I'll have better luck on perfboard.
Here's a video of the circuit:
http://s463.photobucket.com/albums/qq358/adeebm_photos/Random/?action=view&current=ac26b66a.mp4

[dragonriot]

Do these things provide any bass, or is it all treble? It seems in all the videos I've ever seen of a plasma speaker, it's very high pitched, even when the song should be pretty low.

[Alex1M6]

I would say they are more suited for being a tweeter.

[Feca]

Ok, i've finally decided to make this. The only problem is that i cant find any IRFP250 mosfets, however i have a bunch of IRFP254 mosfets. My question is will they work as a substitute to IRFP250 and will I need to make any modifications to the circuit itself later?

[Alex1M6]

IRFP254's will work fine without any need for modifications.

[Alex1M6]

Here is mine up and running on 36v input

I have also now added a totem pole transistor buffer stage between the chip outputs and GDT to help reduce MOSFET heating, which it seems to working somewhat.

[Alex1M6]

Wouldn't more secondary turns on the GDT help make sure the MOSFET is always saturated?

[grenadier]

I'd give it more inductance yes, but you'd need more driving power as well...

[Alex1M6]

Is the SG3525 chip meant to get hot? My chip is getting very hot within about 10 seconds.

[Brubouy]

Yeah !! It works, I made my own PCB for the project using FreePCB, that was a project in its self. I bought the copper coated blank and acid from Radio Shack and used the lazer jet transfer method to mask the board. I used a 24v 5 amp power supply from bestdigitalusa (EBAY) $16 +sh and the MKP cap that digikey is out of, I bought from http://www.tubesandmore.com. I made a cool mahogany and polycarbonate to house the whole thing. Thanks to the author!!!

[Alex1M6]

Does your chip get hot?

[Alex1M6]

To anyone ordering from farnell in the UK get these capacitors http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1198552 , for 50v @ 10,000uF there are pretty compact!

[altaholic]

The 1uF capacitor isn't available from digikey or mouser. What is a good substitute I could use?

[grenadier]

TO ALL WHOM IT MAY CONCERN:

Parts are noncritical. Any 1uF non electrolytic cap will work for this! What this is is an analog electronics circuit, and thus,

#1, It probably won't work for you without tweaking. Analog circuits never do.
#2, Many parts can be swapped for others without much hassle.

[Brubouy]

I used C-MKP1-400 from tubesandmore.com

[Speedmite]

If you made the plasma speaker with the LM7818 and the 8000uf capacitors and ran it at 36v, would 3 9v batteries work? Or do you think there wouldn't be enough amps? And then what about 6 of the larger 6v batteries?

[Alex1M6]

The only type of cheap battery's that would be good for powering this would be the lead acid types, don't get any lower than 7ah though.

[ohnoitsonfire]

pfffft man i still got the same problem... T_T
my flyback does produce +-1 cm sparks at really small intervals but it doesnt create a ''beam'' so its just producing a lot of sparking noice and as far as i can hear unaffected by the modulation if you or anyone else has a qlue please let me know something its quite a dissapointment to get it working this far and being unable to get it working.

[ohnoitsonfire]

i forgot to mention that my circuit also draws verry little current, only 0.3 amps.
seriously if some1 has an idea please let me know i just keep checking my circuit but i cant find any errors.

[Cybot Rules]

try checking the coil you wound on the flyback :) also check your powersource can provide a few amps

[noingwhat]

I believe I have read in a few places that these are supposed to sound better than a regular speaker. Just wondering if there is any truth to that.

[Cybot Rules]

How bad is the "normal" speaker? :P
These tend to lack the lower bass end, but are fairly good considering how they work :)

[geckomage]

hey man i was lookin for a more detailed picture of that circut, but it says its been removed or somethin. can you provide a new link?

[Brubouy]

Try http://www.teravolt.org/sparkspeaker2.php

[geckomage]

thank ya kindly -tips hat-

[Zeroasen]

Do i see it right that the circuit is build for 24volt but also works at 12v?
I want to build a powersource out of an pc supply but the negative 12v only provides 1A (+12v = 16A) so.
Do you have a clue if this will provide more than 9A or will it be limited by the negative 12V?

[reckert1]

hi I want to build this speaker but your 1uf capacitor is on back order for a very long time (BC2076-ND). Is there a substitute i can use?

[cmerling]

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p5197.m570.l1313&_nkw=1uf+mkp&_sacat=See-All-Categories

They're used a lot for audio type stuff, most of these are overkill on the voltage

[IMA_AMISH_GECKO]

So I was curious if there was any way to make this run out of the wall. With out the battery? Would I need to get an adapter or just a plug of some sort?

[ohnoitsonfire]

yes you can run this off the wall but u need to seperate the supply to the IC and the flyback then either that or buy a badass voltage regulator.
you can run it on everthing basicly as long as its dc so suppose you rectify your 230v outlet or 110 or whatever they have in america you can even use that

[HiFiMan]

I noticed you're using a polarized electrolytic 2.2uf capacitor for your input.Wouldn't a non polarized poly cap be a better choice for audio applications?

[awesaomeness5]

um i am not very electronically knowing so does a heat-sink dissipate heat or radiate it?

[HiFiMan]

Actually a heat sink does both.It pulls heat from the devise attached to it and then radiates it into the surrounding air.
They are used to keep the attached devise within it's normal operating temperatures.Without a heat sink the devise would overheat very quickly and be destroyed.

[grenadier]

More of a physics question, but both are the same thing in this case.

[Cybot Rules]

The heatsink pulls the heat away from the chip and then radiates it out to the surrounding air to disperse it.

[awesaomeness5]

thanks man i was not really sure i looked it up on Google and this one site had two functions so i was wondering

[dvnkmmy]

Quick Question. Im confused, is the sound coming from the computer? or the arc? or something else that i missed?

[ohnoitsonfire]

the arc is creating the sound

[jmoreira2]

Hey man, good job with the instructable!
Got a question, what if I got less turns on the ferrite? I could only get 10!

Thanx

[ohnoitsonfire]

hey grenadier ivv spent some time doing some simple measurements and i got some strange readings im putting in 12v dc and measured the voltage over my mosfets and my caps and i measure 12v on 1 mossfet and only 6 on the other also my caps are being charged to +-6v and no higher
what could be wrong?

my setup is drawing next to no amps im running everything uncooled atm and the only thing that gets slightly warm is the voltage regulator the mossfets stay cool to the touch.

im gonna buy some batteries tomorow and just connect them for a sec see what happends.
also after running it for a minute i can smell it yet nothing is getting warm though i can hear my flyback producing high frequenty sound i got it from an tv i found on the pavement so it could be broken.

so have you ever measured the voltage over your mossfets and caps? what were ur results?

i really hope to hear from you soon im kinda confused why one mossfet only gets half the voltage i checked the schemathic tons of times so i could really use a hand here.

[grenadier]

Sounds right; the caps divide the voltage in 2.

[ohnoitsonfire]

glad to hear its not a screw up on my part though sadly this probably meens the only flyback i managed to scavenge is probably damaged inside its casing so i might have to go hunting again lol (ivv been searching the streets for a week before i found this tv ) XD so im gonna buy some lead acid batteries and try them if its still failing im gonna find me a new flyback.

by the way im verry glad your helping me im asking some stupid questions i know, its not that i dont know how to read schemathics but the problem is i have never worked with an IC before so i got totally lost in this one i find it pretty complicated.

[ohnoitsonfire]

a bit of an off-topic question that is related though =D lol

i powered my plasma speaker up for the first time with one of those wall socket transformers and i get some minor sparks (tried to put audio in but i couldnt form a real arc so it doesnt work yet).
so i tried giving it some more juice and connected it to a 24v car battery charger everything worked as expected and i get sparks but no real arc so i measured how many amps i pulled and it whas close to nothing so my reall question is does anyone know if its just the charger limiting the current it gives me? or did i mess up somewhere?
i hope its just the charger if it is ill just buy my batteries and hook em up because my circuit seems fine.

[h40534]

Is it okay if i use a 60v Cap instead of the 40v ? I am having trouble getting the mentioned caps....
Thanks

[ohnoitsonfire]

hey hey first off all very nice instructable even though its my first time on this site i really like it its very clear just got a question about the 50v 0.1 micro farad capasitors, would i get away with using 45v 0.1 micro farad?
because the store only had those at the time i whas there so i told them idd give it a try.

[grenadier]

Yes

[ohnoitsonfire]

hey thanks for the response mate i appreciate you taking time for me,
ill rate you 5 stars any other way i can give u some sort of support? exept for giving u my life savings =p

[Velocirhymer]

As I understand the circuit, you're running 24v into it, then using the voltage regulator to cut that down to 12v. Why not just start with 12v? Is this just to reduce noise?
If I can't find a cheap car battery, how will the performance change given more/less current than 4A, or more/less voltage than 24v?

[ohnoitsonfire]

hi im not sure if ur question has allready been answered i cant help you with the question about performance as mine isnt done yet but about the 24v power supply, if you take a look at the schematic you can see there is a 24v input being brought down to 12v for the IC but there is still 24v going to the cappasitors connected to the flyback.
again if its allready been answered im sorry just my first day here.

[tiger12506]

Another problem with breadboards is cross-talk. That's when high current through parts of the breadboard can overwrite other signals in other wires on the breadboard that wouldn't normally be connected, but are because of induction.

[gregjd5000]

I spent 9+ hours doing and redoing this today...
Is the SG3525 supposed to get really hot? And should there be a flat 4v accross the audio in when not connected?
I never got it working. Any guesses on possible problems? I also used a "cute little flyback" as the transformer and my GDT had 15 or 16 winds. I think everything else is the same.

Thanks!

[dumle29]

me and my friend made on, and we had some problems with it at first, i would recommend going over your circuit with a continuity tester using a highlighter on each of the wires that you have checked on the schematic, then when all errors are found/solved, try plugging it in.

we got ours working right away after doing that. (except some arcing over the bottom of our perfboard (we even had removed the copper pads!) we fixed that by moving the flyback to a separate board.

anyways good luck ;)

P.S. oh and we made a 36 V version and i just wanted to say that the LM7818 get´s REALLY hot, so a heatsink for that is needed. dont know about the dip chip though

[dumle29]

would you be able to use octocouplers instead?

[dumle29]

instead of the GDT

[grenadier]

It might work, but you'd need to find one that can handle >1A and is fast enough for 40+ kHz.

[dumle29]

ok ill go with the GDT :P

[manumanu764]

PITA? what does it mean?
Btw, nice project!

[Maxerdo]

Pain in the a**

[manumanu764]

Interesting...

[waldosan]

lol, that's a great ible, i might just have to make this, if i don't have ready access to battery's on a scale of 1 to 10 how hard would it be to make a "clean" power supply? if i get the volts and the amps right shouldn't i be able to smooth it out by running it through a coil/capacitor? or would that fsck things up?

[Inducktion]

How do you want to make a power supply is the biggest question. If its just a transformer from like, say, radioshack, you should be able to plug it into the wall, and used a Bridge rectifier on it. The rectifier has 4 pins on it, two are for the AC input, and the other two are DC output. You'll also need a fairly large filter cap, something like 10000 uF or bigger. More capacitance means less ripple, which is what noise is.
You put the capacitor in parallel with teh dc output, and then hook it up to whatever you're going to use. Make sure that the rectifier is on a heatsink, and check the polarity of everything.

Good luck

[dumle29]

or you could get an AC/AC transformer, capable of 4 amps, preferably more, and an LM338 which is capable of 5 A

the input of the LM338 should be around 30 V and rectified.

google LM338 and see the pictures.

[dumle29]

if you want to know, the LM338 is a linear voltage regulator, it basically adjusts the output voltage acording to R1 and R2, usually R2 is a variable resistor, since it gives the best accuracy.

(here is a rather expensive though REALLY nice PSU that you could build:
http://www.dogbreath.de/Chipamps/LM338PSU/LM338PSU.html)

also here are some great pictures of a board. Using two LM338´s in TO-220 versions.

[dumle29]

Hey,

i cant seem to find any 40V 8000µF caps. however digikey sells some 10000µF 40V, does it have to be 8000µF if you go for the 36V LM7818 instead?

[dionysus2008]

i got it working!!!!!!!! my first plasma speaker!!! finally. great instructable. and love the block diagram it helped alot. oh and i built the zvs driver u have too. plz post more!

[cmerling]

I scavenged a different MKP cap from a crt, I believe it's this one
http://il.rsdelivers.com/product/vishay/2222-335-10223/335-mkp-x2-polyprop-cap-250v-0022uf/1669436.aspx
Would this work in place of the 332? Also my flyback had some ferrite cores around it, would these help eliminate noise or are they pretty much useless? Great instructable grenadier!

[grenadier]

No, It would not. You need a 3.3nF (.0033uF) capacitor.

Not sure what you mean by "ferrite cores around it"

[dionysus2008]

could i jus parallel three 1nF caps to make 3nF. could that work?

[cmerling]

sorry, one more question. How do you go about wiring atx power supplies in series? I don't want to blow them up if i don't have to

[cmerling]

(removed by author or community request)

[cmerling]

Different link, it's like this
http://www.amazon.com/Ferrite-Core-Cord-Noise-Suppressor/dp/B0002MQGEK

[dionysus2008]

does the zener diodes have to be twelve volts? i aint got that in ma stash only 15v 18v and 22v diodes

[inspecter gadget]

Hello, I Hate asking for help-prefer to work it out myself but I'm at a loss as to what is a matter with my assembly. I Get a weak 5mm spark from my flyback--assuming that this part of the circuit is merely a carrier/ interface via the GDT for inductive modulation to take place- and that when first switched on it should be at least 1/2 -3/4 " without input.

. The chip runs hot also------- my question is if the mosfets were blown would I be able to hear faint music and have a spark or is it residual pickup from GDT and flyback. Lastly flyback has smoothing capacitor built in and does GDT /Flyback proximity matter.

Any suggestion would be greatly appreciated as I do not enjoy failing so miserably. :0

[scottfx2]

Hi,
Nice Instructables, thanks, all is very clear to understand. I made it and it works fine, almost like yours.
I have a question, i would like to put a 39V AC transformator. How i could modify the schema, for all works fine ?
I've tried to put x3 UH4007 in serial, but as i know it was limited to 1A, and speaker works only a little time. I've put for this test too a 7818V.
My wish is to working with this 39AC 7A, transformator.
Almost all things was taken from an older CRT Sun Display 21''.

Great job thanks again !

[kixkato]

I got the circuit built and everything works except the IC gets awfully hot and when the audio source is plugged into anything, the arc gets very noisy and its impossible to get clean sound from it. Without any thing plugged into the audio, its still very difficult to get a quiet clean arc, any thoughts?

Excellent guide by the way

[ggiannuzzi]

Hi ! I have built the plasma speaker but i have the same problem : i can ear some music but the arc is too noisy . How can I do to get a quiet clean arc ??? Thank you, hope you can give me some advise.

[grenadier]

By noisy what do you guys mean, a high pitched squeal?

[kixkato]

No it sound like white noise. It sounds like its hissing.

[tabousa]

i have the same problem
------------------------------------------------------------------
http://www.youtube.com/watch?v=3rjnJitWcec
------------------------------------------------------------------
http://www.youtube.com/watch?v=CESon07DZNI

...some ideas?

[tabousa]

OK finally i have a arc... small but its a arc ( l half then your arc )
Using the pot the arc stop making noise,
but when i send some music its very hard to listen ,the arc coming very noise and overlap the music , and again using the pot and the volume of the source l can listen for very short time and very low volume some part of the song, the noise is back and forth all the time
i used different source of music and cable, mp3 player , cell phone, pocket FM radio and Computer , i cant see any different the noise is the same for any device...
i use 2 APC RBC2 battery 12 v 7.5 ah

some sugestions?

[ggiannuzzi]

Same problem , does anyone got an answer ?? Thanks

[nikolopolis69]

Hey mate, fantastic design. I'm trying to make one but the SG3525 I got off ebay has terminals half as long as a bees' d!#& ... and I'm having a real hard time joining them to anything, any hints or can you get different sizes? mine is a SG3525A. It's about 10mm long by 5mm wide, 8 terminals each side an they are around a millimeter long. Is the one you used this small? Thanks, hope you can give me some advise.

[grenadier]

Sounds like you bought a surface mount chip instead of a DIP. Aside from leading out wires from it there's not much you can do with a surface mount IC, I think fairchild has some DIP style KA3525's in stock if you would like to check there.

[nikolopolis69]

Awesome, cheers mate they look alot more user friendly haha. thanks for your help :)

[lpearson1]

What does the voltage of the capacitors have to be? will 25v work or is 35v better?

[ohowe1]

Hey, would a IRF630 9A 200V 0.35 Ohm fet work? It is the lowest ohm rating I could find? Is the ohm rating the same thing as rds_on??

[Sant92]

hi, great project , but i don't uderstand what pin from the flyback transformer should i use. if you could explain me it would be awesome.

[grenadier]

Whatever pin you are able to draw an arc from will work as the ground pin.

[afilips]

i havea nice flyback but i dont understand how to test it. any help?

[Sant92]

ok, thank you very much

[Mauran]

I built this circuit several times, and it still dosent even draw any current, is there anything you might know offhand that could cause this?
I have built your first plasma speaker several times and that works fine, its just a bit scratchy(anything you might know why?) and i have two AC flybacks which help smooth out the arc and make better music.
But i just cant get this circuit to draw even a single amp. Any ideas?

[goose722]

I have this same problem. I'm starting to think my issue is with the flyback, if that helps.

also make sure to check if you have any break in your circuit or something(although that's obvious)

[goose722]

Wondering if you can use an ignition coil instead of a flyback transformer in this circuit. Wouldn't it accomplish the same goal?

[goose722]

So I prototyped it using a flyback from an old CRT monitor and a GDT i made myself, but when I put the juice in, nothing happens. I've checked and re-checked all of the connections in the circuit with the diagrams you've produced, but no current is being drawn from the PSU I'm using to test it. I'm putting in about 20 V and trying to put in around 3 amps, but it does nothing.

Any suggestions?

[dpower1]

Very nice indeed


www.diysmps.com/forums

[Mythx20]

I can't seem to find any information regarding any modifications to your flyback transformer. The last plasma speaker instructable I was following required 5 turns of a 16ga conductor around the core of the flyback, do you do something similar or leave as is?

[Ice1]

Just a few comments regarding safety for this. I suggest anyone attempting this project should learn about safely discharging capacitors, also everyone should be very cautious when handling this device as it is pretty unsafe if you do not consider safety. Would hate to hear about someone getting hurt building this.

[NoodleUK]

What sort of power does it draw? You said you ran it for 6 hrs, how long do the batteries last?

Just wondering about how to make a more permanent power supply if a PSU won't work.

[grenadier]

Just give it a shot, if you have a nice 24v SMPS it could work. The bigger the flyback the more current it will be able to draw. I have some 100Ah AGM batteries so I can run it for days on those.

Current is also dependent on the frequency too. A higher frequency means more current. At 70khz my speaker uses about 8A, at 40khz it uses 2.

If you use 40v 8000uF caps instead you can apply 36V and make the arc even bigger and louder. Just make sure to replace the 7812 with a 7815 or a 7818.

[NoodleUK]

Me again, questions questions.. I eventually made this up with 2 (different) lead acids giving about 17V in series, but my arc is even smaller than when I tested it with a PSU!

It might be unrelated, but my 'audio' seems to be emanating from inside the flyback, rather than the spark gap.

I really can't seem to get a big enough spark that doesn't squeak. Should I play about with the flyback windings, or the GDT?(already soldered that, d'oh)

[Jonesy939]

I don't know if anyone mentioned this but a Flyback generator produces tens of thousands of volts so be careful with them. A little bit research on google should tell the that in order to over come the resistance of a 1cm air gap, 30,000 volts is required. So be careful on a project like this because you are dealing with High Voltage.

[grenadier]

It's actually 11kV per cm, wikipedia's dielectric strength listing of 3MV/meter is incorrect, though the backasswards administration there won't let me change it.

[jhutton]

will 4 lantern batteries in series work well as the power source?

[dmasson]

Hey, Grenadier, you might remember a few months ago someone emailed you about turning your design into headphones? Anyway, I went ahead and did them. They are nearing completion. Head-Fi ended up being quite a bit of a help. I think I will create an instructable of my own for it, would you mind if I linked to your's for the amplifier design?

[grenadier]

Sure that'd be great!

[Jimmy Proton]

I have an LM340T12 and at the bottom it says 7812 so could that work, if not what is an equivalent transistor?

[grenadier]

LM340T12 is just a higher current version of the LM7812, it should work just fine.

[Jimmy Proton]

OK, thanks.

[jhutton]

what will happen if i use an 18.5v 3.5a power source? will it make a very small spark but still work? or will it do absolutely nothing. Would this be a good safe way to just test if it works?

[gilham]

No one has answered my comment below. What do you guys think I've done wrong? My circuit is almost exactly the same, I took a flyback out of a 25" color tv and the spark is very whimpy.....I don't know what to do to improve it. Please help.

[tabousa]

i finished my circuit, but nothing happen , i used a pc power supply, i need more power for see a tiny arc?

[S0LIDCHA0S-71]

did you check that the atx / npc(assuming ur using an atx) power supplies green wire is connected to the supply case or supply black / ground before using any output?
Note: Don't try to draw anthing above supply rating or it automaticly will shut off and you will need disconnect and reconnect the green wire to make it run again.

[grenadier]

Hmm, have you tried a different flyback?

[jhutton]

What would happen if i used this as my power source?

http://cgi.ebay.com/24V-4A-96W-power-supply-AC-adaptor-LED-Strip-RGB-/260757826060?pt=LH_DefaultDomain_0&hash=item3cb660aa0c#ht_1795wt_972

its 24v 4a power supply...
this seems much more logical than buying a heavy duty battery

[grenadier]

Should work.

[mtzzoraida]

How did you do all the calculations for your circuit? Measurement values in order to figure out what resistances and capacitances were needed? Also, I set up the circuit and the LM7812 is getting very hot, the IC is also getting HOT! What could be the problem? And how can it be fixed? Any help will be appreciated.

[grenadier]

I just tried different values and picked what worked best.

The thing is with analog electronics, there is a lot that can go wrong. By the problems yoou described it sounds like something has been shorted on the IC's output.

[Hav0c]

can i use IRF9540N mosfets they are rated 100v at 23A

[grenadier]

You could try.

[jhutton]

wow. how cool would it be if you hooked up a microphone or guitar to this?
:D

[Jimmy Proton]

Can you make something like this for the ZVS, I can never understand the schematic?

[grenadier]

I did, it's here: http://www.instructables.com/id/High-Voltage-1/#step39

[Jimmy Proton]

thanks

[jhutton]

hi, do you have to use batteries?
can't you use something else? like a wall adapter..
or anything else i would have lying around?
thanks

[dseverinsen]

Hi Thanks this is a great project, I have managed to get mine working OK, I have reduced the size of the resistor that is in series with the variable resistor to increase the frequency and make it a bit clearer to listen to. Where did you get your flyback transformer from? Yours seams to work better than mine.

[7654321]

Aww, I got rick roll'd on your website. Cool ible, wish I had the time to make it.

[shams]

this one is the best sounding plasma speaker !!..

[pbawesome]

since we're working with HV... someone who can't read schematics prooobably shouldn't be working on this

I'm about to rip apart some CRT monitors and pull out some flybacks, some HV caps and other fun stuff. hopefully I get a nice flyback, and some parts I won't have to buy.

I'm going to wait for the MIT swapfest to start again in april and begin this project. This is awesome man!

also, why do the two diagrams say different amounts of current on the power source

one says 24V 10A and one says 24V 4A

[grenadier]

I forgot to change one diagram. You only need about 4A.

[MadScientist101]

what is that switch called and where did you get it?

[grenadier]

It's a knife switch, look on egay and you'll find some.

[MadScientist101]

thanks

[Clubbing At Walmart]

How much did it cost for you? i added everything up and rounded or down to the nearest dollar and came up with about $145.00... is that how much you spent or what? please respond ASAP i need to know because i need to find a project for my DC Fundamentals class in school

[grenadier]

You added something wrong there...

This should only cost about $20, maybe less to make if you pulled the heatsink and flyback from a PC monitor.

[grenadier]

Lolwut? You added wrong.

Altogether it should cost about $25, provided you scavenged the heat sink and flyback from a computer monitor.

[Clubbing At Walmart]

alright ya, thats with everything bought new... i didnt have anything to scavenge from at first but i talked to my uncle... thanks

[Pyrocloud]

I don't suppose theres any way to test you've wound the toroid correctly, I'm just a little unclear about the 'reversing'. Just I'd rather not blow the fets as they arn't easy for me to get.

[Pyrocloud]

Ok nevermind I didnt see the part about testing with a pc power supply.

[tabousa]

i got a flyback from one old Sony Trinitron CRT having 16 pins but I cant realize what is the pin that I use in the flyback
i did a research in Google, but only confused me more
I use a voltmeter and found continuity in this pins: (1 , 2) ,(6 , 7 , 12) and (8, 9), but i cant found any resistance in all of them
of course i'm a newbie ...

[tabousa]

forget to mention...
I followed the instructions from http://lifters.online.fr/lifters/labhvps/tht.htm but using a single +12 v pc power supply and i found these values in the following pin
pin 11 -> 0.18v
pin 13 -> 0.12v
pin 14 -> 0.33v
I'm just guessing but ... I think the V0 pin 11 is the connection of the secundary coil, is that the pin that I'm looking for?

[grenadier]

Well, I usually just do the easy method; move the HV wire to the bottom and see what pin it arcs to. The pin that gives the strongest arc is the ground.

[tabousa]

LOL ...makes sense ....
thanks!

[zodthekonquerer]

Check out his website, he has some interesting projects. Espicially his attempt at a perpetual motion machine, it's very interesting.

[gilham]

I've built this almost exactly as you did. It works, but the arc is very weak. I used two 6800 uF caps in parallel for each of the 10,000uF caps. The circuit is working, I've checked all the signals with an oscilloscope. The problem is the arc, it's very very weak and won't produce any sound. I'm using a 30 volt 4.5 amp power supply. Do you have any suggestions?

[goose722]

I'm looking to build a plasma speaker, and while I was looking around for schematics/instructions, i came across both your instructable, and a report by Mark Barlow of YSU, detailing the construction of a different circuit. here's the link to his concept.

I was wondering if you could comment on which circuit would offer the least feedback and produce the most reliable speaker/circuit... thank you!

[mitchnizzle]

Hey Guys, just wondering if someone could help. I've built this circuit 3 times including a PCB grenadier was nice enough to lend me but i'm still getting either no output or just 3volts on the flyback winding terminal :/ nothing gets hot etc.. just no action. Would one of u blokes mind looking at my pcb or giving us some clues? cheers :/

[bob123]

I've built this circuit and am having a few problems. I keep blowing the 22 ohm resistors on the MOSFETs. Secondly, the lm7812 is getting incredibly hot. I put a heatsink on it, but is this normal? Also, so far, I have not gotten any sort of output from the transformer. Any help would be appreciated. Thanks.

[grenadier]

It seems like you shorted out the 7812 somewhere, and thus the IC is getting no juice.

The only way that you could possibly blow up those resistors is by having one lead on ground and the other lead on 24V. Something must have been wired horribly wrong.

Check your mosfets, they should measure megohms across source and drain and drain and gate. If you get something like a couple ohms or kiliohms they're shot.

[Cleasonsook]

I was wondering if it was possible to make sound

my 3 questions is

how big would it need to be to equal say powered computer speakers ?

or regular home stereo speakers ?

and what would need to change to have it work for either of those

[Betelgeus3]

I don't know about grenadier, but i wouldn't recommend making this much bigger. First off, it's a fire hazard even this small. A big one poses not only threat of fire, but of electrocution. That, plus a HUGE energy draw, compared to normal speakers. I don't know a whole lot about the circuit yet, but making it bigger also lends itself to way more distortion.

[Cleasonsook]

ya I know do not run the unit around fire hazards

so refrigeration would be needed to keep the electronics and the transformer
from burning out

as for the distortion part

it's just a matter of using the right materials
so that it focases the energy correctly

but it would be possible with testing and retesting to find the right combination

I know making one the size of a concert size would be nuts

but some thing about 14 " high would be possible beyond that size
no indoor use or even near any thing that would easy burn

[grenadier]

It's more of a novelty rather than a serious method of making sound. As for a fire hazard, it's not anymore dangerous than a candle. Electrocution is possible, though the simple solution is to not touch the thing while it's on!

A 14 inch arc would use about 3,000 watts of electricity, something that is achievable provided you invest the time and money. Some IGBTs for a half bride or even a full bridge could supply the electricity, the transformer would have to be handmade.

[tomjec]

I guess I don't understand what this is all about. Is the spark supposed to jump in time with the music? or does the spark produce sound waves?
It seems much trouble to animate sound on a small scale.
Thank you for your time and effort.

[Betelgeus3]

You know how extended sparks make crackling noises? Well, this is essentially a way to modify that crackling into a sound that we recognize.

[grenadier]

The arc itself makes the music.

[ARJOON]

what is the maximum voltage input if i change the regulators and also suppose i use a 30000uf 160v cap. i found it in an old train. the capacitor seems to work pretty well.

[grenadier]

At 160V all you need is a 3000uF cap. You'll need to power the modulation circuitry separately though since stepping down 160V might be a little tough.

Since this circuit uses a gate drive transformer, the mosfets and the circuitry don't even need to share a common ground for this to work. It's as simple as doing this:

[grenadier]

God damn jpeg nazis.

Here: http://teravolt.org/Plasma_Speaker_2_files/schem1.png

[ARJOON]

oh you're so kind. when i connected a car sparkplug the quirking sound was gone however sound output was smaller

[VadimS]

Sweet, as soon as I have the funds, I intend to duplicate it.
After that I'll try winding an air core transformer for it, better frequency response, but less efficient.

[VadimS]

Hmm, an air core transformer may have little effect when you consider the pwm topology.

[sata3]

http://i1118.photobucket.com/albums/k608/sata33/iphone361.jpg?t=1295037525

this is the flyback i found, but i'm not sure if there's anything there for me to wrap the wire around.

[grenadier]

Looks OK to me.

[Timofte Andrei]

first speaker that's able to incinerate or even kill the user :D

[Loosewire; SOE Operative]

Wow! This is really cool and utilises my favourite state of matter in an application I had no idea it could be used for.
Does putting an electrically insulated magnet near it change the sound?

[grenadier]

It do not

[mitchnizzle]

hey mate,
I'm having trouble sourcing the SG3525 IC, IRFP250 MOSFETS and the UF4007 Diodes.
What source did you use? my normal suppliers here in Australia are either ex- UK or Ex sydney but $39 delivery due to small order size etc..

Any ideas?

[BlueFusion]

Farnell (now element14) is your friend.
au.element14.com
Min $10 order, but so long as you're ordering enough to hit that, it's free next day shipping no matter the order. If you come up short just order some LEDs or other random stuff to fill your parts box :)

[grenadier]

You could try eGay. You can use any diode so long as it's ultrafast (recovery time less than 200ns).

The mosfets can be substituted for any fet that can handle >100V and >15A.

You can use the KA3525 IC instead of the SG3525.

[grenadier]

Forgot to mention the diode needs to have a voltage rating >600V.

[steveastrouk]

So the "flyback" is only being used for its turns ratio ? Neat solution. A flyback circuit doesn't lend itself to being modulated.

Its nice to see a gate drive transformer ! I haven't used one in years - I usually use one of the special ICs now.

Getting higher volume might require an exponential horn to couple the arc to the air effectively.

Oh yeah, and make sure you vent the ozone - its nasty.

Steve

[robot797]

ozon smells nice
and how more ozon how longer the arc

[grenadier]

Very little, if any ozone is made.

[steveastrouk]

Ozone is poisonous.

[robot797]

a flyback is the easyest thing to modulate
if you modulate a engine it beeps or sings
but it will not turn
unlet the frequentie is verry low

[steveastrouk]

No, that's why other designs suffer from "burning hot transistors"

[robot797]

do you care if i rebuild this circut (and place a instructable of it)
only with a 555 and more power

[grenadier]

Aww, I wanted to do that in the future...

[1800yolk]

Man I would love that, think you'll get around to it anytime soon?

[robot797]

i will start in this week

[robot797]

well it is your call

it is your instructable
so you decite if i may do that

[kcedgerton]

Thanks for that schematic, it makes it much easier to understand.

[sata3]

what kind of wire do i need?

[grenadier]

Just regular copper stuff.

[compukidmike]

First of all, thanks for this instructable (I voted for you, hope you win). It's the first plasma speaker that I got to work without blowing up! My only concern is that my arc is about half the length of yours, and the circuit only draws 1.6 amps. Not that it's a bad thing, but it should be capable of more. I'm wondering, would my arc increase if I put fewer turns on the flyback primary?

[grenadier]

Fiddle with things. Try a bigger/smaller GDT, try more/less turns on the flyback. See what works best.

[childB]

I can't vote for this enough times - this is a really very solid, great instructable. Good job!

[jamilm9]

Could I use a computer power supply -12 volts and +12 volts for the 24 volt input?

[froggyman]

Actually, after taking a look at the real schematic http://www.teravolt.org/Plasma_Speaker_2_files/schem.png it says that you can use rectified AC so it should work with a computer PSU.

[jamilm9]

Thanks for this answer. Would this one also work.
http://cgi.ebay.com/24-VOLT-CCTV-POWER-SUPPLY-24VAC-20VA-TRANSFORMER-24V-/370458350687?pt=LH_DefaultDomain_0&hash=item564109d45f
I'm not sure how many amps this speaker needs.

[The Lightning Stalker]

No, not enough amps.

[jamilm9]

I found a computer power supply that can provide 15 amps at +12 volts and 0.8 amps at -12 volts. This would make 24 volts at 15.8 amps I think? The colored schematic says it only needs 10 Amps. Can anyone confirm this for me. Thank you

[legless]

Oh no don't go there at all. You need 24V above ground (0V in this case) If you want to experiment with these higher currents in projects use car batteries in series or a truck battery or get a lab power supply that can output a reasonable amount of current.

[jamilm9]

Ok. So the cheapest way i found to supply 24 volts at 10 amps is this.
http://cgi.ebay.com/24V-10A-240W-Switching-Power-Supply-LED-Strip-light-/220694164876?pt=LH_DefaultDomain_0&hash=item336265b58c
Can anyone else find anything cheaper. Thank You

[grenadier]

Just get a pair of lead acid batteries man! Every hobbyist should have a large collection of batteries IMO. I've got two 100Ah 12V AGM batteries in the basement. (at 76lbs each they don't move much though).

[jamilm9]

I see where your coming from but i wanted to be able to run this off the grid and my original budget was $50 for it. Batteries + chargers are expensive plus shipping to Canada. I guess I will just have to wait until I can spend a bit more on it.

[The Lightning Stalker]

That would just barely work, but will get pretty hot. You might need a fan. Check the amp draw of the finished circuit with an ammeter to be sure it's under 10A

[grenadier]

No, it would make .8 amps.

Don't use negative voltages because this circuit is 0V ground. If you use -12V ground and plug in an audio source that is at 0V ground you'll kill the audio source and possibly the circuit.

[childB]

I found what I feel is the best way around this...

Head out to your local thrift store where you'll inevitably find 50+ sets/lone speakers (specifically if the set is incomplete; if you point it out they'll usually make it $1 or just give it to you). I got some really great Logitech home theater consoles and a few JBL home theater sets. If you don't end up just using whatever you find as it is, the power supply in these high end speakers tends to produce some exceptionally clean power. I hooked the JBL one up to a scope, and it was very, very clean, especially compared to the other options. One can usually find cheap incomplete high end speakers at thrift stores.

Great instructable, btw.

[froggyman]

hmm.. it says "many amps". My guess is though, that you should be fine with that transformer... And if it doesn't work you will only be out a couple bucks

[froggyman]

You wouldn't want to. Any power source that is converting to DC will put in extra noise in the power. While that may not matter for your motherboard, it does matter for an audio project like this.

[josephlebold]

Noisy power will cause a computer to freeze up. I would say a computer power supply would work good. The only problem with a power supply jamilm9 mentioned (15 amps at +12 volts and 0.8 amps at -12 volts) is the -12 volt side, It must match the +12 volt perfectly in amperage or the -12 volt side will go up in smoke.

[grenadier]

Actually the DC blocking caps filter mains hum. That's one reason why they are so big.

[skrubol]

Another shortcoming of solderless breadboards is that they aren't capable of carrying a lot of current. If the pins of your power device are too big to fit, there's a good chance you may melt/burn your breadboard if you're running at full power.

[Kyxter]

This looks fantastic. I'm ordering parts from Digi-Key right now :)

Couple of typos in the Instructable:
- in the part list: LM7182 should be LM7812, although the link is correct.
- in Part 8 you reference eBay as eGay, not sure if that was intentional but I thought I'd mention it just in case.

[grenadier]

#1 is fixed,
#2 was intentional.

[eight]

OMG, you must be the bravest and smartest person here.
KUDOs for such a lovely project.
Truly you have this man's respect!.
Thank you so much!
- Dave
AKA Eight
from Down Under, on the left.

[The Lightning Stalker]

There was a flyback driver circuit in an old issue of Electronics Now that uses less parts. http://users.silenceisdefeat.com/~lgtngstk/Sites/transist/transist.htm

[seabeepirate]

Any idea what kind of voltage you're getting out of your flyback? This seems like it could also be used to drive a SSTC if only a small one, I don't really know that much about them yet. I'm hoping to finish researching a good driver to make a set of singing tesla coils soon. Any input? I think I'd like to build one of these whether or not I can get a singing tesla coil up and running.

[grenadier]

10kV, 9mA.

[seabeepirate]

Hmmm... That sounds like it would be enough for a very small tesla coil. That's about 30 watts less than a couple of rough spark gap tesla coils I saw. How close to max power is that?

[surbarus]

can you make this speaker using a plasma globe?

[grenadier]

Nope. A plasma globe circuit just makes high voltage, no modulation at all.

[robot797]

i am gonna speak against you

you can make a plasma speaker out of a plasma globe

you seek the mofsfet inside the plasma globe
remove it and replace it with something better
and dont conect the base
the base is fed from this circut (or any old 555)
and also what you should do is make a ground conection between this circut and the circut of the plasma globe

when you are done the plasma globe circut gets the high voltage
and this circut (555) does the tuning
if you have done it right you will have a modulated plasma globe

[grenadier]

I meant you can't make it from just the parts in a plasma lamp.

[robot797]

that is true

[dyly]

YAY! a circuit for a plasma speaker that works! finally!!!!

[madrobot3600]

this is a definite build for but how much will all of this cost?

[grenadier]

About 20 bucks.

[madrobot3600]

thanks

[freakyqwerty]

You should put it in side a case so only the plasma arc is veiwible...

[godofal]

when you say it's not that loud, how "loud" is it?
and if the problem is blowing the IC, couldnt you get a heatsink/double up on IC's/get stronger IC's/whatever other random solution to boost the sound more?

awesome project though, would really look awesome inside some glass vial in a steampunked stereo or something, ignoring the part that it also makes sound!

[grenadier]

I'm not sure exactly how to compare it. It can be easily heard in a quiet room. Hmm... I'd say about as loud as a smartphone's speakers.

The problem isn't boosting the sound electrically, it's just that as you turn up the volume the music gets distorted. That's the arc's fault, not the chip's.

[robot797]

not the arc the arck can produce 120DB of clear sound
it is the circut tuning

[grenadier]

120db of music from an arc? I'd like to see that.

[freakyqwerty]

Not from a home-made one you won't, well probly not...

[robot797]

i cannot make it myself (yet)
but your setup could be stable up to 30KV
it only needs a frequentie of 20-40KHZ
and 50V on the primary windings
and you should have 10-20 cm arks with 50 db (i beleve that was right)

i could get 30db out of a 555 (it explodes beond that) with a normal speaker

[Minifig666]

You could ramp the voltage to 35V. That would make it louder and shouldn't cause distortion. Amplifying the input just puts noise on the lines which upsets the IC.

[grenadier]

I could, but I'm already pushing 95 watts through this flyback. I don't think it'll handle any more without getting hot.

Plus those are only 32V caps.

[robot797]

if the flyback is getting hot
well get an other flyback
are the caps the small
well buid a circut that is maddable and use cheap high voltage parts 100V+
when i work with tubes i use 450V caps even when the voltage never reaches 250V

it can be stronger

[grenadier]

Eh, this one's good enough.

[robot797]

we know
it were tips for other people

[e.montvidas]

wait, so you're saying over 9000 is bad, goku is a dissapoint.

[spark light]

hey grenadier! nice too see that you joined instructables! growing the hv community! -W.N. seen mine?

[rimar2000]

Awesome, congratulations.

[xdissent]

SUPERTRAMP!!!!!!!!! Brilliant!

[scazman]

Great job. This is definitely on my list of future projects.

[jrossetti]

Agree with you there, this is on my list too. Too awesome.

[godofal]

same here!
my list is getting really long :P
someday....

[CameronSS]

Lovely! I saw this on Hackaday, and as I was reading it, I was thinking, "Hmm, if only he would write this up as an Instructable."

[AndyGadget]

Impressive! Plasma speakers never cease to amaze me.
(Great track too - Supertramp are one of my favourite bands.)

[grenadier]

They are awesome when they don't blow up. This is the only circuit that hasn't given me problems.