Plasma Tweeter on Kickstarter

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Ich kann das Thema Ozon nicht mehr hören/lesen

Hallo,

wann immer irgend jemand nur die Worte Plasma Tweeter schreibt scheint sich jemand anderes sich berufen zu führen Ozon zu schreiben! Schon fast wie "Gute Morgen" => ""Was soll daran bitte gut sein"...

Klar gehen Plasma Tweeter mit Ozon und EMV einher, doch es gibt Beispiele, dass Entwickler sich hierüber Gedanken machen, und es gibt technische Lösungen hierfür. Ein paar Links zu solchen Projekten wären vielleicht konstruktiver! (Googelt mal nach "Georg Green Plasma Tweeter")

Auch vermute ich dass es wesentlich mehr "Ozon Schreier" gibt, als Leute die schon einen Plasma Tweeter gebaut haben. (Sonst gäbe es mehr Hilfestellungen und Tips).

Meine Aufbauten erzeugten zwar Ozon, bei der Größe des Wohnzimmers (ca. 250m^3) konnte ich dies jedoch nie riechen, anders als in der Werkstatt.
Viel interessanter wäre eine Kapselung, so dass die Temperatur um die Flamme steigt, Ozon ist schließlich nicht sonderlich stabil bei hohen Temperaturen.

Leider sind die Quarz-Glas Kammer des DuKane nicht mehr erhältlich. Ein Nachbau aus Porzellan wäre hier vielleicht eine Alternative.

So, das musste mal raus!

Grüße
GvT
 
Sorry, here's the translation

Hello,

sorry, I didn't notice the thread was in English, so here's the translation:

whenever someone writes Plasma Tweeter someone else seems to be called to write OZON! Just like "goog morning" => "what shall be good about this morning"...

True, there is Ozon and EMC involved with Plasma Tweeters, but there are examples where developers thought about this and developed technical solutions to handle this. A few links regarding this topic would be more constructive and helpfull! (Google => Georg Green Plasma Tweeter)

I asume there are sigificantly more "Ozon-Writers" than there are people who have actually built a PLasma Tweeter. (Otherwise there wood be more hints and assistance...)

My Plasma Tweeter setups produced Ozon, but given the size of the livingroom (250m^3 <> 9000ft^3) I could never smell it. This was different in my workshop.

Much more intersting would be an enclosure around the flame to work against th ozon as it is not stable at high temperatures.
Unfortunately the quarz-cells of DuKane are no longer available. Maybe a rebuilt from hard-porcelain would be an alternative.

Well, I just had post the above.

Greetings
GvT
 
Thank you !!

This is a subject That I find very interesting and have been wanting to explore more into myself for many years.

I know the that ozone seems to be one of the biggest concerns but I would think that this is not that much of an issue in a large ventilated room as you said.

More importantly I know what the benefits are as I have seen some very good examples show up recently.

But none of these examples have been very well documented as far as Frequency Response ( I already know it should be pretty darn flat), Frequency Bandwidth as per size of the flame, and, Peak SPL per size of the flame as well as the power it takes to achieve such levels.

There has only been about three examples that I have found that show this data and very slightly at that.

Not to mention the poor examples with overdriven issues that make them sound very bad.
This is something I wish not to dwell upon as this is a fairly simple and easy fix of staying within their linear parameter ,and well, by just not overdriving them.

Amongst the many large PWM powered tesla coiled versions, I have found two very good compact versions that were quite loud and sounded clean (for the most part).

One was a 500 watt Class E amplifier driven model.

The other one used used a compact ceramic type transmitter tube at about 1000watts of power.
This thing was incredibly loud with about an 8" flame by the video I saw.
But again no data and just a demonstration.

I can compile the links if one is interested in seeing them as I found them at 4hv.org
website.

It would be great worth to hear some input on this subject from someone whom has experience of building and\or has used such devices.

I personally have mastered my own techniques of building ESL's with great satisfaction and I am ready to explore the next plateau of extreme quality of sound reproduction.


Cheers !!!

jer :)
 
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My History on PLasma Tweeters

Hallo

-now on English right away-

I have built up a plasma tweeter (PT) following Haumann's instruction. At first I had hardly any flame. He tried to help me there after contacting him -thanks again- so I modified the feedback and shortened the resonance coil. I got a stable flame, up to 1 inch without overheating the PL519 at 24MHz. The flame was safely self-staring. operating at 650V.

Then I ripped it all apart and rebuilt it on 325V level. Got a slightly smaller flame but no self start.

I tried several different preamps, lastly the Aikido by J. Broskie. The gain was not quite sufficient.

Used different electrodes (silver, copper, tungsten 3.2 and 4.xmm) differnt shapes for the tips.

Tried to attach the flame to a horn with little success. I used a quarz-glass tube 8mm dia to house the plame -> echo.

-----------------------------------

So I still have a lot to do before I will be done:

1.) decide for a starter circuit
- temporarily switch to 650V (dual voltage power supply)
- use a HV spark as suggested by G. Green
- use an automated "screwdriver" (relay with a wire) to start the flame
(wasn't this Magnats solution)
- figure out how Lasche is doing this
2.) find a way to attach the flame to a horn
- rebuilt DuKane's quarz cell
- design my own porcelain cell
3.) select an audio amp
- currently I am thinking of a tube transistor hybrid

and finally: put everything together!
Unfortunately I will not start working on this before fall. But then now would be the time collecting information.

Greeting
Georg
 
Aside from Peter's version here is a solid state version that I was following a long while back but there haven't been any updates except one although that data maybe included in these pages already,

Our Senior Project

second version (tube),

Plasma Tweeters- started June,1999

Plasma Tweeters- started June,1999

Schematics

I never saw an update using the 813 tube and I was going to get some but then their prices just skyrocketed by the time I was able to get some, so then I held off.
And then I figured I would get some 3CX100's (4CX's) or something for direct drive ESL amps and plasma's, but they started to disappear quickly as well not to mention again the prices.
I had two 833a's but one somehow lost its vacuum so it is going to go in an RF linear sometime.

I will compile those other video links as well as they are quite impressive.
I have a few tubes a 6146a and 6BQ6 and various other worn out sweep tubes that are in a couple of RF amps that I have that I could use but I think that I am going to go the solid state route myself.
Mainly because of cost and I don't have a matched pair of tubes that are of the same type that I can spare.

jer :)
 
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Resonance circuit

Hallo,

I will keep on the tube road or my plasma. The PL519/EL519 are not that expensive and I don't think that matched pairs are needed for the RF circuit.

In general a PT consists of a
- power supply (325V, 600V 650V etc. can be found in schematics)
- a resonant circuit (amplified by a HV transformer (flyback) or dirct)
- a modulation circuit (audio amplifier)

As for the power supply I prefer the lower voltage ones for reasons of costs. 600V components and shieldings cost more than 300V ones.

With the resonant circuit I tend toward a direct, tube driven one. High voltages and low currents are the domain of tubes. A penthode incorporates exaclty what I would be looking for: at least 2 controls! One for the overall current (audio frequency) and one for the RF. Gate 1 and 2.

Modulation circuit: the amplitude needed I would like to discuss here, the type of circuit I consider secundary.

---------------------------------------------------------

To build a plasma tweeter I need to built a plasma producing circuit first. The need for modulation should be in mind, the how to comes later to my experiences.

When I look at all the tube based PT schematics published they a similar:

a 15 to 19 turn coil => 4 to 6 uH between anode and corona
a 100uH between power supply and corona
=====> I don't know any of the physical relations there! I would be greatfull if someone would point me to according information.

a feedback loop from the corona to gate 1
with 2 to 5 pF capacity
=> due to my experience this is not frequency relevant rather than to get the tube into the correct switching point.

---------------------------------
what I read on the web and don't understand: the two coils ideally should have the same inductivity... any comments on this?

-----------------------------------
some words about safety:
yes, you do need to shield the whole experiment! (my power-supply gets crazy if no plasma flame is present => high RF Voltage)
some of the schematics published don't have a capacitor between and anode and the resonance coil => the fame s DC coupled to the power supply: NOT A GOOD IDEA ==> use a capacitor!!!!

Here's a ling to a schematic by Georg(e) Green:
http://img91.imageshack.us/img91/5372/schalte4117fk1.gif
I intend to use this RF circuit, a different analog amplifier.
The ignition problem is not solved there.

Greetings
Georg
 
Marvel the green lantern - THE PLASMA FLAME IS PURPLE!!!!!!!

Hello Celvin,

it't pretty easy,

you can built a plasma tweeter with a tube (1st purple lantern - e.g. DuKane )
you can built a plasma tweeter with a fet (2nd purple lantern - e.g. Magnat)
you can built a plasma tweeter with a flyback transformer (3rd purple latern)

so take your choice.

The questions around the oscillator are more pressing than the way you create the plasma.

How to you start the corona?
- mechanically
- with a spark
- etc...

How do you shield it
- coils in the supply lines, etc...

How can you increase the soundlevel
- putting it against a tile (George Green)
- attaching a horn (DuKane, Lasche, etc.)
- livng with it as is...

I'd rather exchange about these questions than about green lanterns. I guess this thread might see the red lantern => train has moved on...

Greetings
Georg
 
Plasma Twitter or O-Zone generator

Plasma Twitter or O-Zone generator
I believe I remember Nelson Pass developed and worked with a plasma speaker he may have something to say about this topic of interest. What some people with sensitive lungs or asthma even a small amount of O-Zone generated by plasma is irritating and harmful.
 
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