Completed Plasma Speaker / Tweeter

Richard, Thu Mar 20 2008, 12:38AM

Finally finished building this driver board to power a flyback, with custom made discharge reflector :)

You can see it in action, together with the prototype design & video HERE


1205973250 1211 FT0 Plasma10
Re: Completed Plasma Speaker / Tweeter
EDY19, Thu Mar 20 2008, 12:43AM

That is a very nice project for such a new member! smile Keep it up! I recently finished my VTTC plasma tweeter, and the sound quality is great, however i used a digital camera video recorder, so the sound is awful in the recording! In real life, it really does sound quite fantastic smile Nice clean work, too smile
Re: Completed Plasma Speaker / Tweeter
northern_lightning, Thu Mar 20 2008, 01:18AM

sounds and looks awesome!!
Re: Completed Plasma Speaker / Tweeter
Ken M., Thu Mar 20 2008, 01:33AM

Indeed Nice work.
Re: Completed Plasma Speaker / Tweeter
Mates, Thu Mar 20 2008, 06:45AM

Richard, this one of the best playing plasma devices I've ever seen! Great work!

I'm pretty surprise you can get that sound from a fly-back. I have a pile of questions if I may... wink

Is this a regular modern type TV or PC monitor fly-back?

What freq. do you operate it?

And (I'm almost afraid to ask) what about sharing the whole schematics with us?

Thanks,
Mates
Re: Completed Plasma Speaker / Tweeter
Experimentonomen, Thu Mar 20 2008, 10:21AM

I agree, i saw this vid this morning and finding you as a member here was a total suprise.

Im planning to build one as well with one of these, a TL494/SG3525 and some fets:
Oldstylefbt
Re: Completed Plasma Speaker / Tweeter
Richard, Thu Mar 20 2008, 10:28AM

Thanks for the positive comments, it's good to know I'm going in the right direction !
The next logical next step has to be a stereo version. Should be a fun challenge :)

Decided to keep away from using dance/electronic/synth music to demo it, as this can hide a multitude of failings in the sound reproduction (distortion & poor frequency response etc). Perhaps some strong female vocals or classical piece ? - might make for some interesting listening.

@ Mates - There's nothing special about the design, but I did pay special attention to the decoupling of each stage, to prevent unwanted oscillations & noise. The PCB design took the longest - the reflector was made of scrap.

You don't want a thick, long, white-hot arc. This will look impresive, but brings lots of problems. Excessive power consumption, overheating windings, electrode damage, instabillity and RF noise.

The small DC flyback, is from a colour portable TV - the operating frequency is 110Khz



Re: Completed Plasma Speaker / Tweeter
GeordieBoy, Thu Mar 20 2008, 12:03PM

Hi Richard,

Great project and a very nicely built prototype too.

Although I personally like the dance track version better! tongue

Link2

...somehow a little distortion doesn't matter there wink and it's cool watching the modulation on the scope amazed

The best vocal track I found to play through my singing tesla coil was "Sailboat" by Katie Mellua. It has a very clear and sharp vocal line which is quite dynamic too. Or anything with acoustic piano will show up the distortion if you are wanting material for a harsh test.

I used Rapture by Iio originally, but there's a lof of corona hiss in my demo at 250kHz.

Link2

-Richie,
(Newcastle UK)
Re: Completed Plasma Speaker / Tweeter
Dr. Dark Current, Thu Mar 20 2008, 12:26PM

omg HFsstc-freak, where did you get that monster flyback?

Re: Completed Plasma Speaker / Tweeter
flannelhead, Thu Mar 20 2008, 12:38PM

Yea, and the picture is a monster too. I thought the max picture width was 400, not 1400.
Re: Completed Plasma Speaker / Tweeter
Steve Conner, Thu Mar 20 2008, 01:12PM

It's 400 now mistrust
Re: Completed Plasma Speaker / Tweeter
Experimentonomen, Thu Mar 20 2008, 02:16PM

I got it off ebay, just like 7 modern ones, 7 identical ones.
Re: Completed Plasma Speaker / Tweeter
Richard, Thu Mar 20 2008, 02:49PM

Great looking flyback that !!! - I wish I could get my hands on one.

We have a problem here in the UK now, in that all domestic electrical waste (TV's microwaves & anything remotley useful to us), goes for recycling. At one time you could buy the odd TV/VCR for parts, from your local tip, but not anymore. It's all piled up & shipped away somewhere. Really frustrating when you see an old Philips G8 TV, that you know has a really good 30KV AC flyback in it...

Still, such is 'progress'

Thanks 4 the suggestion of Katie Melua - have to agree though Richie, a fast track IS more entertaining :)
I'll connect up the RGB LED sequencer later & try to post another video later today.

Re: Completed Plasma Speaker / Tweeter
uzzors2k, Thu Mar 20 2008, 05:50PM

Crystal clear sound! Did you use frequency or pulse-width modulation?
Re: Completed Plasma Speaker / Tweeter
bob golding, Thu Mar 20 2008, 11:10PM

hi richard,
yes the new WEE regs are a pain. i got about 80 microwaves and dismantled them before the new regs came in. didnt have enough room to do all the tv,s as well:-)) one way of getting useful parts is the freecycle network. if you join your local group and ask for old tv,s and microwaves you will get them,and they are free. nice project,been on my list for while but havent got around to it yet.

bob
Re: Completed Plasma Speaker / Tweeter
Richard, Fri Mar 21 2008, 06:21PM

Many thanks for the info on the freecycle network - nearest is Birmingham - just too far to make it worth while :(

Got another video uploaded HERE with the RGB LED backlighting/sequencer working.

Now considering trying to wind my own transformer to try & improve the top end frequency response.
It falls off at 12Khz on the scope - commercial ion plasma tweeters can acheive 50+kHz

@Uzzors : I'm using FM modulation in the videos shown, but the board can be configured for PWM as well.



Re: Completed Plasma Speaker / Tweeter
Experimentonomen, Fri Mar 21 2008, 08:27PM

That is due to the system beeing aircored and oscillating at several MHz. Ferrite cores are limited to around 100KHz.
Re: Completed Plasma Speaker / Tweeter
Richard, Fri Mar 21 2008, 09:36PM

Absolutley ! - I've found above 115kz (with the ferrite material flybacks use), the output drops suddenly.

The commercial units all use RF air-cored transformers and sizeable horns, to acheive a decent volume.

Perhaps an electrode-based disharge with an air-cored transformer might be the way forward ?

The large modulated TC's I've seen, do perform OK, but seem to produce a great deal of corona noise....

Re: Completed Plasma Speaker / Tweeter
GeordieBoy, Tue Mar 25 2008, 01:31PM

> Got another video uploaded HERE with the RGB LED backlighting/sequencer working.

Wicked - Nice one! Haven't heard that tune in a while either!
Sarah Cracknall is a babe cheesey

-Richie,
Re: Completed Plasma Speaker / Tweeter
Dr. Dark Current, Tue Mar 25 2008, 09:48PM

Richard wrote ...


@Uzzors : I'm using FM modulation in the videos shown, but the board can be configured for PWM as well.
Ok, so how is it done? Do you feed your input signal to the frequency timing resistor pin of the IC or where?

Oh, and one more question, is it push-pull or bridge drive?


Re: Completed Plasma Speaker / Tweeter
lpfthings, Sat Apr 12 2008, 01:08PM

Hey as some of your comments in the vid suggest, do you have a kit for sale? I'm mainly looking for a PCB. Nice work, pretty clear sound too, especially the highs!
Re: Completed Plasma Speaker / Tweeter
Dr. SSTC, Tue Jun 17 2008, 06:58AM

richard we just want the schematics so if you wouldnt mind just giving them to us
Re: Completed Plasma Speaker / Tweeter
Reaching, Tue Jun 17 2008, 05:06PM

jovica93 wrote ...

richard we just want the schematics so if you wouldnt mind just giving them to us

lol. if you want something, just as a shematic, this way to ask is one of them who will never lead to success..
Re: Completed Plasma Speaker / Tweeter
Dr. SSTC, Wed Jun 18 2008, 02:11AM

well i dont know how to ask if i made something good i would share it with youse
Re: Completed Plasma Speaker / Tweeter
teslacoolguy, Wed Jun 18 2008, 02:35AM

If i were to ask for the schemattics i would say,"Hi. Would you mind sharing the schemattics with us because that is one of the coolest things i have seen in a long time." Be polite to people so other prople can be polite to you.
Re: Completed Plasma Speaker / Tweeter
FastMHz, Wed Jun 18 2008, 09:19PM

This is quite impressive!! Awesome cheesey
Re: Completed Plasma Speaker / Tweeter
..., Wed Jun 18 2008, 10:59PM

Richard wrote ...

Absolutley ! - I've found above 115kz (with the ferrite material flybacks use), the output drops suddenly.

The commercial units all use RF air-cored transformers and sizeable horns, to acheive a decent volume.

Perhaps an electrode-based disharge with an air-cored transformer might be the way forward ?

The large modulated TC's I've seen, do perform OK, but seem to produce a great deal of corona noise....



the next step up this would be some type of air cored transformer (generally a Tesla coil running in quasi class E) running at 4+MHz At this point the arc becomes silent and very high frequencies can be produced
Re: Completed Plasma Speaker / Tweeter
Dr. SSTC, Fri Jun 20 2008, 10:18PM

...

wasnt the whole point of this to make a singing arc not a singing airdischarge
Re: Completed Plasma Speaker / Tweeter
Dr. SSTC, Fri Jun 20 2008, 10:18PM

...

wasnt the whole point of this to make a singing arc not a singing airdischarge
Re: Completed Plasma Speaker / Tweeter
teslacoolguy, Sat Jun 21 2008, 04:35AM

It is and it still will be. All they are saying is instead using a flyback transformer and have it arc from it's hv lead to it's ground lead you would have a air cored transformer arcing from it's top lead to it's bottom lead kind of like i bipolar coil.
Re: Completed Plasma Speaker / Tweeter
Dr. SSTC, Sun Jun 22 2008, 04:13AM

ye but this would take up lots of space if he decides to sell these which he probably will he'll propably make his own transformer with better insulation and smaller size
Re: Completed Plasma Speaker / Tweeter
Zorink, Sun Nov 09 2008, 11:10PM

WOW! I would gladly pay for a schematic of that
Re: Completed Plasma Speaker / Tweeter
Luke_Duke, Thu Nov 13 2008, 07:00PM

oh dear this is a total awsome plasma speaker the best i've ever seen .
You did a great job!

I would also pay for that rockin schmematic .


Ps: The blue Led on the PCB looks great :)
Re: Completed Plasma Speaker / Tweeter
okk, Fri Apr 23 2010, 05:23AM

A Pulse Width Modulator.
good things