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Old Jun 20, 2008, 2:02 PM   #1
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I have a device called a Tesla coil that I use in my science class to excite special gas filled tubes so that the emisson spectra can be viewed. It puts out 26,000volts of electricity at very low amperage, so it's not as dangerous as it sounds. I can also attach standard light bulbs to it and general a plasma field. That's what is shown here. It took a bit of fussing to find the right shutter speed, apreture and ISO but here are my best results.

Thanks for looking,

Steve


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Old Jun 20, 2008, 2:04 PM   #2
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Here is a top down view. BTW, I have wanted to take pictures of this phenomenon for quite a while so I am glad this challenge came along.



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Old Jun 20, 2008, 3:33 PM   #3
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I have seen those plasma globes in novelty stores. There are several different kinds and shapes. However, after playing with several of the models, I don't recall ever feeling anything except heat coming from the globes. Do you know anything about these curiosities such as what gas(es) is/are used. Is the glass globe coated with anything to help it attract the plasma. In other words how do these things work?

Great photos including the two in your other posting.

Cal

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Old Jun 20, 2008, 3:52 PM   #4
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Cal, googling "How do plasma globes work? will yeild a number of explanations, but this one from the "Light Energy Studio" website is pretty short and to the point.

I'm guessing that the reason my palsma ball tingles and yours does not is due to the fact that I am using many thousands of volts to power mine ( close to 26K ) and the store bought globes only use a few hundred volts. I can turn mine down so that you can not feel a thing. However, what's the fun in that when you are having junior high kids touch the bulb. They want to be "ZAPPED!" They sqeal with delight every time they get a good zap. He he, to be honest, every time they get zapped so do I. :lol: It's all harmless, good fun.

I hope this answers your question.

Plasma Globes/tubes
Hows does a Plasma Globe work?
(source; LightEngeryStudio.com)
A plasma device, whether it is a tube or a globe, is a sealed glass piece that has what we call a "plasma" gas mixture inside. The term "plasma" is technically any ionized gas in a discharge tube (fluorescent lights, neon tubes, etc.) In this case it refers to a specific lighting effect. The gas mixture is primarily made up of inert gases such as neon, krypton, xenon, argon, helium, etc. A "dopant gas" mix is mixed in in very small amount to form the thin filaments of light. The dopants gas also helps determine the color of the discharge. These dopants are carefully formulated, without them the globe (or tube) would just glow uniformly and have no filaments. The gas lights up with a high-voltage, high-frequency power supply that essentially broadcasts a field of energy causing the gases to light up, much like the Northern Lights. Nicholai Tesla worked with these devices and published an article describing how to make them as early as 1910. Since a high-voltage field exists around a plasma device, no conductive materials should be used to build the base. The power supply also needs to be located close to the globe. The wiring also needs to be kept away from any other conductive surface. No insulation is sufficient to insulate the wiring from a conductive surface.

One more shot of me holding the bulb.


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Old Jun 21, 2008, 12:03 AM   #5
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Thanks
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Old Jun 21, 2008, 4:47 PM   #6
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Steve,

This stuff looks other worldly, brings back memories of my high school physics days circa late 1950's.

Aloha
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Old Jun 21, 2008, 11:40 PM   #7
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Looks really cool, Steve.

Patty
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