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FrozenGate by Avery

FEELER: Plasma Speaker Kits

bassa said:
Hallo.
I am new at the forum. I howlp I don't ask any stupid questions...


I managed to do a plasma speaker, but I wanted to be with Tesla coil.
My power is DC 12V, but the coil does not come niches. If you can give me some advice or tell me something about your schedule that you have made.

Plasma speker - YouTube

Sorry if my English if I do not understand very well.
Click to expand...

Your english is good enough, do not worry!

You did a fine job making a "flyback" transformer plasma speaker, very good audio quality with almost no distortion. That is not easy.

Making a tesla coil is far more difficult than making a flyback transformer work, and getting a tesla coil to play music is another level of difficulty in addition. Tesla Coils are what is known as a "high Q system", which means a very small change in any variable makes a huge change in performance. Typically you make a plasma speaker by modulating either the supply power or the drive dignal of a high voltage transformer. Most people do it by modulating the drive signal as this does not require high power audio and a very large modulation transformer, but there is a draw back; in order to get good audio out of the tesla coil it takes a large variation in drive signal. High Q systems often begin to suffer big losses or just plain fail when you vary a drive signal significantly. So it is a very complex process to correctly design a working musical / audio tesla coil. Building it is a challenge to even the most experienced.

My advice; read up on tesla coil theory and principles in your native language (if you tell us what that is we might be able to give you the right direction to look in). Then read up on "Class-E topology for inverters and amplifiers" as well as the "half bridge inverter" and "H bridge inverter". Once you have a basic understanding of these systems you can begin to piece together how they fit together with a basic tesla coil to make the SSTCs we make today.

As for your plasma speaker with the flyback, you can only get louder audio out of it by increasing the input voltage and drawing a larger arc to move more air volume. Try 24V if you can, but remember that depending on what ICs you use they may not survive anything over 15V. I would need to see your schematic to tell you if it can handle more power.

Again, nice job!
 





Hey guys,

Just ordered a batch of new PCB's with the new design, hopefully this will fix the problems ive had!

Upgrades done:

  • made the board smaller 110x100 down to 90x90mm
  • made a lot of the traces smaller & shorter.
  • Isolated a lot of components from the ground plane.
  • Made the fan come on as soon as power is connected (not switched)
  • Put the control circuit on a switch, so you can run the fan without running the system, for thermal control.

Things and I have been working on this for a few weeks, ive ordered the boards through Itead instead of Oshpark this time too. Bet you cant guess the color they will be!


Fingers crossed it works like it should!

On another note, ive ordered the pcb components for a SSTC kit, ill aim for using a 6" spun toroid.

Stay tuned!


Fiddy.
 
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Thanks for the quick reply.


Basically I think I'm aware of most things savvy said. Because I studied electronics, but there is still much to learn.
I use this scheme which is quite simple. http://www.mh-audio.nl/gif/plasma/arc-speaker_TL494.png
And I tried with this coil I was able to do for two hours.
http://www.freeimagehosting.net/wll3h

Any recommendations for other schemes or improvements (or whatever it was). Or some literature to send me a link that you think would be useful to me.

P.P.
At what frequency you set the PWM?
 
Last edited:
Sigurthr said:
Your english is good enough, do not worry!

You did a fine job making a "flyback" transformer plasma speaker, very good audio quality with almost no distortion. That is not easy.

Making a tesla coil is far more difficult than making a flyback transformer work, and getting a tesla coil to play music is another level of difficulty in addition. Tesla Coils are what is known as a "high Q system", which means a very small change in any variable makes a huge change in performance. Typically you make a plasma speaker by modulating either the supply power or the drive dignal of a high voltage transformer. Most people do it by modulating the drive signal as this does not require high power audio and a very large modulation transformer, but there is a draw back; in order to get good audio out of the tesla coil it takes a large variation in drive signal. High Q systems often begin to suffer big losses or just plain fail when you vary a drive signal significantly. So it is a very complex process to correctly design a working musical / audio tesla coil. Building it is a challenge to even the most experienced.

My advice; read up on tesla coil theory and principles in your native language (if you tell us what that is we might be able to give you the right direction to look in). Then read up on "Class-E topology for inverters and amplifiers" as well as the "half bridge inverter" and "H bridge inverter". Once you have a basic understanding of these systems you can begin to piece together how they fit together with a basic tesla coil to make the SSTCs we make today.

As for your plasma speaker with the flyback, you can only get louder audio out of it by increasing the input voltage and drawing a larger arc to move more air volume. Try 24V if you can, but remember that depending on what ICs you use they may not survive anything over 15V. I would need to see your schematic to tell you if it can handle more power.

Again, nice job!
Click to expand...
Thanks for the quick reply.


Basically I think I'm aware of most things savvy said. Because I studied electronics, but there is still much to learn.
I use this scheme which is quite simple. http://www.mh-audio.nl/gif/plasma/arc-speaker_TL494.png
And I tried with this coil I was able to do for two hours.
http://www.freeimagehosting.net/wll3h

Any recommendations for other schemes or improvements (or whatever it was). Or some literature to send me a link that you think would be useful to me.

P.P.
At what frequency you set the PWM?
 
bassa said:
Thanks for the quick reply.


Basically I think I'm aware of most things savvy said. Because I studied electronics, but there is still much to learn.
I use this scheme which is quite simple. http://www.mh-audio.nl/gif/plasma/arc-speaker_TL494.png
And I tried with this coil I was able to do for two hours.
http://www.freeimagehosting.net/wll3h

Any recommendations for other schemes or improvements (or whatever it was). Or some literature to send me a link that you think would be useful to me.

P.P.
At what frequency you set the PWM?
Click to expand...

If you wish to run a Tesla Coil in flyback mode ("single ended operation" - one mosfet only) you can use the TL494 & MOSFET you used for your plasma speaker, just wind the tesla primary directly on top of the base of the tesla secondary. Set the PWM frequency to the natural resonant frequency of the tesla secondary. Use an online calculator to determine the natural resonant frequency of the secondary by inputing the wire diameter, winding length, and coilform diameter of your secondary. The self-capacitance is not trivial to calculate, which is why you don't do the standard Xl = Xc resonance calculation to determine f0. Most people who make these single ended sstc's place a small value high voltage capacitor across the Drain and Source of the MOSFET which in effect turns it in to an out of tune class-E topology. You will have to play around with the capacitance to determine what value works best (least FET heat). This type of coil greatly stresses the MOSFET and its body diode so be prepared to blow up lots of silicon. Look up Steve Ward's "Micro SSTC" for a good example.
 
good hello,

I have my new revised PCB's from ITEAD :D

iteadpcbs.jpg


Gunna solder one up as soon as i can fingers crossed!

Stay tuned.
 
Meatball said:
Any updates on how these boards turned out?
Click to expand...

Theres something wrong with the new boards, the thing didn't light up at all which is annoying, ive put this on hold for a while as im building a house.
 
Building a house? Bit of a step up from your previous projects don't you think :D
 
thanks man, i will get back into it one day, maybe ill send a board to some smarter guys to help figure these problems.
 
Things said:
Haha :D

DSCF9183.jpg


DSCF9184.jpg


'Scuse the taped up primary and secondary :D

Hoping the fan there will be enough for the heatsink, we shall see :)
Click to expand...

Good greif, that's a work of art!!!
Well planned and put together. I am serious considering building one with my next students
weather it be in Malaysia, Singapore or Brunei.

Death by stereo!!! :beer::beer::beer::drool:

Inspiration of the day!!
 
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Cheers :)

Fiddy, I have an EE friend that isn't so busy at uni at the moment, I'l see if I can dig up the original schematics and see what he has to say.
 
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