Does anyone have any knowledge on the pros and cons of plasma discharge (high voltage, low current) Arc discharge (High current. low voltage) and flame (oscillating flame) methods of audio reproduction and how to produce them? Looks to be a very obscure subject with little to no information on the web.
Ozone is solved with active carbon. Nitrous oxide is a more troublesome component that the plasma discharge method produces.
I'm less concerned about toxic gases for now and more concerned about the methodology.
The plasma discharge method is what people usually refer to when they talk about plasma stuff in audio.
I'm particularly interested in the other two options, arc discharge and flame methods.
I've seen a few things written about flame but not much.
Arc discharge, also known as carbon discharge is a low voltage option so it shouldn't produce ozone but it might still produce nitrous oxide.
I cannot find any written material on this method other than the fact that it exists but I am extremely interested in it because it trades high voltage for high current. I'm trying to think how you are supposed to create a plasma arc without voltage.
I'm less concerned about toxic gases for now and more concerned about the methodology.
The plasma discharge method is what people usually refer to when they talk about plasma stuff in audio.
I'm particularly interested in the other two options, arc discharge and flame methods.
I've seen a few things written about flame but not much.
Arc discharge, also known as carbon discharge is a low voltage option so it shouldn't produce ozone but it might still produce nitrous oxide.
I cannot find any written material on this method other than the fact that it exists but I am extremely interested in it because it trades high voltage for high current. I'm trying to think how you are supposed to create a plasma arc without voltage.
Low voltage arc sounds fairly nonlinear to me. Try it. Nitrous is a lot of fun compared to ozone.
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There are many ways to create a plasma discharge - you simply have to ionize the gas in question. You can use your basic avalanche breakdown - high voltage. You can use rf energy, something around the ubiquitous 13.56MHz works well. It helps to avoid creating reactive species that corrode the surroundings. Helium is pretty benign and not so hard to ionize.
Look up some of the work by Dr. Braithwaite in the UK Open University. One of his students recently published a thesis (Yvonne Sutton).
There's load out there is you search for it.
I remember a few decades ago one of the big Japanese welding companies was looking for ways to reduce the high noise levels from welding equipment and ended up showing off a computer driven welding torch playing symphony !!
Look up some of the work by Dr. Braithwaite in the UK Open University. One of his students recently published a thesis (Yvonne Sutton).
There's load out there is you search for it.
I remember a few decades ago one of the big Japanese welding companies was looking for ways to reduce the high noise levels from welding equipment and ended up showing off a computer driven welding torch playing symphony !!
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Yep, I've run many a carbon arc spotlight and projector. Normally 24V, like welding. You touch the rods to start the arc, then pull them apart. Xenon lamps are similar, but use a strike circuit to start the arc, since the electrodes don't move.
I've done a little reading on the talking flame stuff and IIRC it had to be modulated on an RF carrier. Could be wrong, someone here will know.
I've done a little reading on the talking flame stuff and IIRC it had to be modulated on an RF carrier. Could be wrong, someone here will know.
Always thought it needed voltage to jump the gap. Good to know you don't require a 15kv supply to attempt this stuff.
Plasmas are effected by magnetic fields.
What about running a continuous arc and modulating it with an electromagnet? Never seen this done.
Plasmas are effected by magnetic fields.
What about running a continuous arc and modulating it with an electromagnet? Never seen this done.
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I remember looking through the welders glass window as a human servo when the rod's burn rate varied from the auto feed. Then there was the film stopping with the shutter open.
Yep, the auto feed was never perfect, but soooo much easier than spotlights that have manual feed. You'd want some kind of auto advance system for an arc speaker.
Here is an old Popular Science article on the talking flame. This is one from 1968 and I've not seen it before. IIRC, the first experiments were done in the 1920s
FLAME AMPLIFICATION
And the FM arc:
Make a Plasma Arc Music Speaker — Electronic Music | Make:
FLAME AMPLIFICATION
And the FM arc:
Make a Plasma Arc Music Speaker — Electronic Music | Make:
Flame looks like it has the least obstacles for practical end results. The biggest problem is how to sustain a giant flame without buying fuel canisters constantly...
An astonishing demo of music was a friend's AR2 with Ionovac tweeters. Fabulous. 1968.
I think treble deserves good headroom in order to be able to play brief but sonically important peaks.
B.
I think treble deserves good headroom in order to be able to play brief but sonically important peaks.
B.
I heard the plasmatronic speakers at a show around 1980. They sounded the best and there were lots of fancy speakers there ( Infinity IRS, different esl).
I think they cost $28k ( and this was 1980!).
Despite the cost, people bought them and there’s even a website on them.
I think they cost $28k ( and this was 1980!).
Despite the cost, people bought them and there’s even a website on them.
Is it for real?
It really does not matter what is the source of electrically conductive "gas" media that expands/contracts due to value of the current flowing through it. Plasma that conducts gets energy from chemical reaction "flame" or electrical discharge "arc". There are so many ways of skinning the cat but important thing to pay attention to is properties of the gases resulting from the operation of such thing, especially arc based. Ozon and nitrogen dioxide are not safe to play with not mentioning possible allergic reaction to. There are clips on tube showing amount of NO2 developed. Would you like to experience anaphylactic shock if not careful? Secondly, arc creates high intensity UV, which is as "good" for eye sight and skin as aforementioned gases to your lungs.
Cheers...
P.S. Surely ICE is not that safe either but you've got the idea. 🙁
It really does not matter what is the source of electrically conductive "gas" media that expands/contracts due to value of the current flowing through it. Plasma that conducts gets energy from chemical reaction "flame" or electrical discharge "arc". There are so many ways of skinning the cat but important thing to pay attention to is properties of the gases resulting from the operation of such thing, especially arc based. Ozon and nitrogen dioxide are not safe to play with not mentioning possible allergic reaction to. There are clips on tube showing amount of NO2 developed. Would you like to experience anaphylactic shock if not careful? Secondly, arc creates high intensity UV, which is as "good" for eye sight and skin as aforementioned gases to your lungs.
Cheers...
P.S. Surely ICE is not that safe either but you've got the idea. 🙁
Alan Hill created and sold the Helium-fed, Hill Type-I loudspeaker beginning in 1978. It is a glow discharge (3kV @ ~150mA) in open air. It is dead quiet and is able to produce ~105dB from ~1kHz to well beyond audible. It creates no Ozone (too hot), but does produce some oxides of Nitrogen. The entire speaker consisted of the tweeter, a 6.5" Bextrene cone midrange, and 14" treated paper cone woofer. It is a bi-amped system as the plasma is controlled by five class A tube amps. I know all this because I worked for him.
Arc discharges (low V/ High I)are nonlinear and unsuited for high quality audio.
Arc discharges (low V/ High I)are nonlinear and unsuited for high quality audio.
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