Re: Hill plasmatronics patent ...
Go to Google Patents and type "Sound production using large volume plasmas"
It's not an application, it's an issued (and now expired) patent.gentlevoice said:
Go to Google Patents and type "Sound production using large volume plasmas"
Re: To abzug ..
It was platinum-plated tungsten and then the plating diffused into the substrate. This was done according to US patent 4,240,878 (but I used tungsten instead of tantalum because I had easier access to it). Note that the baking must be done in an inert atmosphere, which I couldn't do myself since I don't have sufficient heat source to seal quartz glass (regular glass tubes won't withstand the necessary temperature), so I had a scientific glassblower do for me.
No, it wasn't platinum... do you know how much platinum costs dude.gentlevoice said:
It was platinum-plated tungsten and then the plating diffused into the substrate. This was done according to US patent 4,240,878 (but I used tungsten instead of tantalum because I had easier access to it). Note that the baking must be done in an inert atmosphere, which I couldn't do myself since I don't have sufficient heat source to seal quartz glass (regular glass tubes won't withstand the necessary temperature), so I had a scientific glassblower do for me.
to abzug
Thanks for the feedback!
I've noticed that both you and "george green" use tungsten for electrodes. I can see that it has a very high melting point which I assume is desirable for plasma tweeter applications where high temperatures and much power has to be dumped are present - are there other reasons why you used tungsten - besides maybe price?
Platinum is expensive I can see (!) - when I read about its qualities it is characterized as an outstanding catalyst, corrosion resistant, and with a relatively high melting point. Are those the reasons you used this metal? Could gold be used instead - or maybe iridium which is cheaper and also more corrosion resistant?
If you are also the previous diyaudio member called "prune" I would say that the work you dig on the plasma tweeter then looked very interesting to me....
Regards,
Jesper
Thanks for the feedback!
I've noticed that both you and "george green" use tungsten for electrodes. I can see that it has a very high melting point which I assume is desirable for plasma tweeter applications where high temperatures and much power has to be dumped are present - are there other reasons why you used tungsten - besides maybe price?
Platinum is expensive I can see (!) - when I read about its qualities it is characterized as an outstanding catalyst, corrosion resistant, and with a relatively high melting point. Are those the reasons you used this metal? Could gold be used instead - or maybe iridium which is cheaper and also more corrosion resistant?
If you are also the previous diyaudio member called "prune" I would say that the work you dig on the plasma tweeter then looked very interesting to me....
Regards,
Jesper
You cannot use gold--it's melting point is far too low. Tungsten cannot be used bare unless you use an inert gas all around it, as otherwise it will burn up with oxygen in the atmosphere. Try turning on an incandescent lightbulb with its glass envelope broken to see what happens to the tungsten filament.
Even the plated electrodes I mentioned will eventually erode due to diffusion of oxygen reaching the substrate (and the plating itself slowly diffuses as well). Perhaps some conductive ceramic can be used as a permanent solution, but good heatsinking should allow reasonable replacement periods to be achieved with the plated electrodes. I still think it's a better approach than refilling helium tanks, especially since there is a worldwide helium shortage that is not going to go away.
Even the plated electrodes I mentioned will eventually erode due to diffusion of oxygen reaching the substrate (and the plating itself slowly diffuses as well). Perhaps some conductive ceramic can be used as a permanent solution, but good heatsinking should allow reasonable replacement periods to be achieved with the plated electrodes. I still think it's a better approach than refilling helium tanks, especially since there is a worldwide helium shortage that is not going to go away.
Hello 🙂
I've had a similar thought today - using a spark plug to try out how/if it works (for microphone purposes) .. maybe abzug/other people have an opinion/experience with this?
Easter greetings from Denmark....
Jesper
I've had a similar thought today - using a spark plug to try out how/if it works (for microphone purposes) .. maybe abzug/other people have an opinion/experience with this?
Easter greetings from Denmark....
Jesper
Indium? That's strange. I think it must be irridium, as indium's melting point is extremely low. Unless you mean as an alloying element to other metals used.
I don't see how you can machine a spark plug to a configuration for making a glow discharge as in a Plasmatronic-type device.
I don't see how you can machine a spark plug to a configuration for making a glow discharge as in a Plasmatronic-type device.
It is iridium...
It is iridium I'm thinking of.
Instead of helium: Is there any other gas that could be convenient for this purpose? Maybe a gas that can be held "firm" by electronegativity or some other mechanism within the confines of a metal mesh of some kind so that it may not need to be replenished in more than small amounts? Neon, Argon or ...?
Feel like smiling
😉 🙂 😎
It is iridium I'm thinking of.
Instead of helium: Is there any other gas that could be convenient for this purpose? Maybe a gas that can be held "firm" by electronegativity or some other mechanism within the confines of a metal mesh of some kind so that it may not need to be replenished in more than small amounts? Neon, Argon or ...?
Feel like smiling
😉 🙂 😎
None of these is cheap in the amounts discussed. I'm skeptical you can get significant retention with electrostatic repulsion, and if you have a grid, I'd be concerned about diffraction. Might be worth a try though.
I'd rather simply not deal with cylinders of compressed gas.
I'd rather simply not deal with cylinders of compressed gas.
I have this idea of approching the plasma speaker from an electrostatic point of view.
Modulate a gas flame between two grids @ 5 kV or such... can it work?
GD
Modulate a gas flame between two grids @ 5 kV or such... can it work?
GD
Don't mean to be a spoil-sport, but back to the issue of ozone. Anybody with a history of vinyl records should have been interested in electrostatic air cleaners. And that means: ozone.
Ground-level ozone is profoundly unwholesome - takes the rubbery stretchiness out of your lungs, I believe. Sounds bad, eh? Attacks all kinds of stuff. Bad for the environment, perhaps not at music volume levels.
But since it is doubly-profoundly easy to smell, you can smell it before it harms you. In other words, smelling it may not mean the concentrations are toxic but I think there's no practical way to keep track of levels that are toxic.
And on the other hand, ozone quickly dissipates when fresh air is introduced to a room.
Since activated carbon will filter the ozone smell, I suppose it must be filtering the ozone gas.
I hope this post establishes (1) that ozone is worth considering and (2) I don't know much of a coherent nature about it.
Ground-level ozone is profoundly unwholesome - takes the rubbery stretchiness out of your lungs, I believe. Sounds bad, eh? Attacks all kinds of stuff. Bad for the environment, perhaps not at music volume levels.
But since it is doubly-profoundly easy to smell, you can smell it before it harms you. In other words, smelling it may not mean the concentrations are toxic but I think there's no practical way to keep track of levels that are toxic.
And on the other hand, ozone quickly dissipates when fresh air is introduced to a room.
Since activated carbon will filter the ozone smell, I suppose it must be filtering the ozone gas.
I hope this post establishes (1) that ozone is worth considering and (2) I don't know much of a coherent nature about it.
Trying to herd cats....
smells like "fresh air after a llightning storm" (which may or may not really relate to the lightning discharges miles away)
Not sure I can do a good job here. Not unpleasant smell just a hint of acrid. Distinctive and not confusable with other smells. Not sweet or organic. Vaguely "electrical" (again, may or may not relate to electric discharges around HV gear).
Pick up a used electrostatic table-top air cleaner from your local thrift shop and sniff when running - 60% chance it is over-ozoning the air.
Ah, now there's a great idea: electrostatic air-cleaner plasma speakers, with iridium spark plug electrodes. Well, at least it could be a source for HV power supplies for plasma or ESLs.
(Sorry folks, I was just tossed from a BMW motorcycle board for crimes against the moderator; a bit giddy this morning.)
smells like "fresh air after a llightning storm" (which may or may not really relate to the lightning discharges miles away)
Not sure I can do a good job here. Not unpleasant smell just a hint of acrid. Distinctive and not confusable with other smells. Not sweet or organic. Vaguely "electrical" (again, may or may not relate to electric discharges around HV gear).
Pick up a used electrostatic table-top air cleaner from your local thrift shop and sniff when running - 60% chance it is over-ozoning the air.
Ah, now there's a great idea: electrostatic air-cleaner plasma speakers, with iridium spark plug electrodes. Well, at least it could be a source for HV power supplies for plasma or ESLs.
(Sorry folks, I was just tossed from a BMW motorcycle board for crimes against the moderator; a bit giddy this morning.)
ad ozone
Ozone smells a bit like Chlorine. ;-)
Regarding scavenging:
Citing US 7291312
Ozone is widely used for treating drinking and sewage waters, germicidal treatment of facilities/equipments in food factories and the like, household disinfection, etc., because of its strong oxidative power. It is also used for forming oxide films of wafers in semiconductor industry. However, ozone induces health problems such as headache, vomition and pulmonary edema by its strong oxidative power, so that spent ozone after use should be decomposed and detoxified. Conventional methods for decomposing such ozone involved contacting exhaust gas containing ozone with activated carbon or a metal having ozone-decomposing ability supported on zeolite or thelike.
End of citation
Fill a long tube having a large diameter with activated carbon. The length will provide for very good air-carbon contact, the large diameter will allow sufficiently low flow velocities (and thus low noise fans for sucking air into the tube).
ad using 5kV and a gas flame:
check
http://www.swtpc.com/mholley/PopularElectronics/May1968/Flame_Amplification.htm
Regards
Peter
Ozone smells a bit like Chlorine. ;-)
Regarding scavenging:
Citing US 7291312
Ozone is widely used for treating drinking and sewage waters, germicidal treatment of facilities/equipments in food factories and the like, household disinfection, etc., because of its strong oxidative power. It is also used for forming oxide films of wafers in semiconductor industry. However, ozone induces health problems such as headache, vomition and pulmonary edema by its strong oxidative power, so that spent ozone after use should be decomposed and detoxified. Conventional methods for decomposing such ozone involved contacting exhaust gas containing ozone with activated carbon or a metal having ozone-decomposing ability supported on zeolite or thelike.
End of citation
Fill a long tube having a large diameter with activated carbon. The length will provide for very good air-carbon contact, the large diameter will allow sufficiently low flow velocities (and thus low noise fans for sucking air into the tube).
ad using 5kV and a gas flame:
check
http://www.swtpc.com/mholley/PopularElectronics/May1968/Flame_Amplification.htm
Regards
Peter
Peter,
This is most interesting!! Certainly much less hassle than a plasma tweeter?
Although both types pose a burn hazard.
GD
In the flame speaker, you NEED a gas you can burn. You can burn it even if you are not listening to music. It might even explode without making (wanted) sound.
An RF plasma won't do nothing once you have pulled the plug. That is certainly less dangerous.....although I am intigrued by the idea to use an H2/O2 gas mixture generated from water electrolysis. If I ever have enough time and feel sufficiently suicidal, I might give it a fair try...
So much for hassle.
Peter
An RF plasma won't do nothing once you have pulled the plug. That is certainly less dangerous.....although I am intigrued by the idea to use an H2/O2 gas mixture generated from water electrolysis. If I ever have enough time and feel sufficiently suicidal, I might give it a fair try...
So much for hassle.
Peter
Isn't H2+O2 explosive?
Isn't it the reason that water electrolysis is only performed using DC current?
Isn't it the reason that water electrolysis is only performed using DC current?
yip.
generate h2 / o2 by dc electrolysis.
let the generated gases flow to a burner.
burn the -->explosive !! you are correct!!! <<<--- gas to produce the flame.
modulate the flame using ac modulation.
as I said: I ll do that once I feel sufficiently suicidal. Until then I ll do less dangerous things such as juggling running chain saws.
There is even someone who already predicted in the internet that one day someone will be stupid enough to do so....
Peter
generate h2 / o2 by dc electrolysis.
let the generated gases flow to a burner.
burn the -->explosive !! you are correct!!! <<<--- gas to produce the flame.
modulate the flame using ac modulation.
as I said: I ll do that once I feel sufficiently suicidal. Until then I ll do less dangerous things such as juggling running chain saws.
There is even someone who already predicted in the internet that one day someone will be stupid enough to do so....
Peter