[Corvettaholic]

So when you have high voltage, pointy things in the circuit have a corona around them. What exactly is happening around that corona? All those fun atmospheric molecules getting ionized? I mean, I SEE colors therefore something is going on with all the oxygen/nitrogen/carbon dioxide.

[Donaldson Tan]

i thought u were talking about corona beer when i saw this thread listed in the table of contents..

[Uberman]

maybe you are seeing colors because your drunk

[Mitch]

highly ionized atoms will just be colored. Of course it all depends on what element and stuff like that.

[Corvettaholic]

So if I had a high voltage discharge in a pure nitrogen atmosphere versus pure argon, it would be a different color right? When discharging high voltage, does it matter what gas I use as a medium? I'm wondering if some work as better insulators or conductors of a charge.

[eugenedakin]

Hello Corvettaholic,

Yes, you are definately on the right track.  the colours that you see due to voltage discharges are similiar to the discharge occuring from common vacuum light bulbs.  Some coloured light bulbs (and neon signs) emit different colours due to the small amount of gas in their tubes.  

This is common to the equipment placed on satellites to determine the composition of another planets atmosphere.  An emitter (voltage discharge) creates a light of known colours which is passed through the gas of a planet, and the difference between the original emitted colours and the recieved colours helps determine which elements are present on the planet.

Yes, some gases work as better insulators and conductors of charges.  More ionic chemicals are generally better electrical conductors, whereas noble gasses (neon, argon, etc) tend to be poorer electrical conductors.

Corvettaholic, you have some of the best questions!!!

Take care,

Eugene Dakin Ph.D., P.Chem.

 

[Corvettaholic]

I'm glad this thread was revived! Why? Because I just acquired a broken Bud Light neon sign. Actually, only the bottom tubing is broken, but the upper tubing is still intact. When plugged in, it emits blue, white, and yellow all from different tubes. So now I need to fix the bottom tube. I was just going to take the bottom tubing to a welding shop, punch a small hole in the glass and fill it with nitrogen, and very quickly reseal it. It'll be a redneck job to be sure. I also remember reading somewhere that the gas pressure is important.

Which leads me to: so we have gas #1, at 1 ATM. Would it be a better conductor or worse if I increased the pressure to, say, 5 ATM? I'm guessing it would be better because there's more atoms available (more junk floating around in the same volume) therefore it would be much easier to pass along electrons which therefore means more current. I might have to add a bigger ballast resistor to the tube if this is true, for current limiting purposes.

I read space.com quite a bit, and they go into spectronomy sometimes. Thats really neat how we can 'see' another planet's atmosphere just from colors! But a lot of elements can give off a wide range of colors, therefore to narrow it down is the proper method to hit the element in question with a lot of colors, and see what it gives out? Narrow it down based on a whole slew of data? I'm going to assume you can't just blast *one* particular wavelength of light at something to figure out what it is.