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Plasma Globes - Where to buy

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LAN_403

Xplorer

Sun Aug 22 2010, 06:57PM

Registered Member #2416 Joined: Sun Oct 04 2009, 04:23AM
Location: Oceanside, CA
Posts: 91

Hello,

Does any one know of a source of large plasma globes, >10in? The only one I could find, besides the overprice ones on Information unlimited, was this one. It's 15in in diameter for $400, that's not too bad I suppose.

But I'd also like it not to be sealed, as I'd like to be able to experiment with different gasses and pressures to get different effects. Does anyone here collect them? Is it possible to unseal a sealed globe and exchange the gas mixture? I have an 8in globe with that typical mixture that yields the thin blue streamers with red tips., but I would like something more along the lines of this.

But have no idea of how to go about changing the gasses inside and I'm assuming it's probably incredibly difficult if not impossible.
I like them because they're essentially mini silent "tesla coil" like displays. I'd love to have one on display in my living room.

Thanks!

-Tony

ScotchTapeLord

Sun Aug 22 2010, 09:47PM

Registered Member #1875 Joined: Sun Dec 21 2008, 06:36PM
Location:
Posts: 635

Have you considered making your own? If you could make a cap for a big glass bowl that allowed a wire in and a way to depressurize it and fill it with gas then all you would need is a flyback transformer and driver, as I understand. I'm not sure if it has to be AC or DC, though. That way you're only limited to what size bowl you can find and seal. Unless I'm completely wrong in my understanding of plasma globe theory.

Plasmana

Sun Aug 22 2010, 10:00PM

Registered Member #3108 Joined: Thu Aug 12 2010, 05:37PM
Location: Worthing, England
Posts: 72

Like what scotchtapelord said, you can make your own or you could even meet the glass blowers and have them to blow up a large glass bulb for you.

ScotchTapeLord wrote ...

I'm not sure if it has to be AC or DC, though.

Plasma globes only work with AC

Xplorer

Sun Aug 22 2010, 10:58PM

Registered Member #2416 Joined: Sun Oct 04 2009, 04:23AM
Location: Oceanside, CA
Posts: 91

They'll work with pulsed DC too won't they? I know the frequency affects the pattern and color. Yes I have considered making my own. I'm in the process of making a simple pickle jar vacuum tube. But unless I have a Pyrex bulb custom blown it won't look very professional.

I plan on dropping a lump of dry ice into the jar and immediately start evacuating much of the air before all of the ice sublimes. Then I'll turn on the power and slowly pull a vacuum on the CO2 until I see some discharges. CO2 apparently makes nice bright white/blue arcs.

-Tony

Adam Munich

Sun Aug 22 2010, 11:42PM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

Blowing glass isn't very hard. You'll need to make a glory hole first. Build a pit out of bricks, then cover it with a grill grate, then bricks atop that. Next light a charcoal fire in there. Feed air via a vacuum cleaner. In a few hours it'll be a couple thousand degrees.

Next, gather up a load of soda lime glass from jars, and put it into a flower pot. Put it in there to melt it.

When it's nice and gooey, pick some up on the end of a copper tube. Then blow into the tube while it's spinning. Have another person smooth out the bubble with a wet newspaper.

There you go, a nice glass ball! Now the hard part. Annealing. You'll need to keep it over a propane flame, and lower the flame slowly over the course of 8 hours. There's an 80% chance it will crack.

(now you see why they're so expensive)

...

Mon Aug 23 2010, 12:21AM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

There were some big ones that needed degassing on american science and surplus, I am not sure if they still sell them but I know they were very cheap (<$20).

ScotchTapeLord

Mon Aug 23 2010, 12:32PM

Registered Member #1875 Joined: Sun Dec 21 2008, 06:36PM
Location:
Posts: 635

Plasmana wrote ...

Like what scotchtapelord said, you can make your own or you could even meet the glass blowers and have them to blow up a large glass bulb for you.

ScotchTapeLord wrote ...

I'm not sure if it has to be AC or DC, though.

Plasma globes only work with AC

In that case, a flyback without diodes would be needed.

Xplorer

Mon Aug 23 2010, 02:51PM

Registered Member #2416 Joined: Sun Oct 04 2009, 04:23AM
Location: Oceanside, CA
Posts: 91

I don't think I'll try blowing my own, lol, for two reasons. First I doubt it's that easy and I'd be hard pressed to make it look nice and symmetrical. Secondly is for the fear that it will violently implode it I pull a vacuum on it. They should also be made from Pyrex.

I do remember American Science and Surplus having them now that you mention it, and they we're cheap. But they're out now.

-Tony

Adam Munich

Mon Aug 23 2010, 02:58PM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

Biggest I could find.

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