Actually, whether "sparky" is a real person (which I doubt judging by the lightning through his hand) or not doesn't really seem to matter. He can't be inside the Faraday cage. The fluorescent lightbulb around his head is lit, and as we all learned in Physics 101, there will be a net zero electromagnetic field inside the cage.
The reason that the fluorescent lightbulb is lit is because of the stupidly huge electromagnetic field created OUTSIDE of the Tesla coil. That field will light fluorescent lightbulbs in the vicinity (an area proportional to the square root of the coil power...)
This actually brings up a good point... Tesla himself was a big advocate for using Tesla coils to power people's lights. He even at one point built a tesla coil large enough to light an entire town (I don't remember exactly where it was.) However Tesla coils, while convenient because nobody needs silly things like cords or sockets for their lightbulbs, use up stupid amounts of electricity and are REALLY noisy. The story continues that Tesla finally finished the project, flipped the "big switch" and drew so much power that he shut down the power grids in several states.
Just some nice, Sunday morning, anecdotal remarks.
The story of the.jp box REALLY SCARED THE SH*T OUT OF ME! I'm sure that my box is much more vulnerable than that paranoid.jp box was, and I'm CERTAIN that I would NEVER detect an intrusion such as this. The only way I would not loose sleep over something such as that is knowing that there really is no way that I can prevent it.
On some Linux installations, I have used the BRU 2000 backup software. It costs a couple of hundred $$$, IIRC, but it is really excellent software with many features. So If you are willing to spend some money, that should work for you. I must defer to others, however, in the area of doing it with free tools.
There are a couple of liquids which you might consider for your cooling to avoid the liquid problems. The one I would look strongly at is acetone.
Yes, the stuff smells bad, but it will remain as a liquid (and not get gooey or gelataneous) down much colder than -30 or -40 C... I use dry ice/acetone baths all the time, and it's still very much a liquid at -70C.
It's immiscible with water, so you won't have any water-contamination problems, and any water that hits the cold acetone will instantly freeze.
Although it has a relatively high vapor pressure at room temperature (i.e. it smells bad) the vapor pressure isn't nearly as bad at cold temperatures, and you won't smell it at all. And you won't smell it anyway if you have a cover on the case.
So anyway, you have my vote to use acetone as your cooling fluid.
Here's an idea on silent cooling... evaporation. Evaporation is a exothermic process (gives off heat) and thus is a cooling process. So if you immersed something (like the cooling fins on the CPU) in a cheap liquid with low vapor pressure (perhaps methanol) then the temperature of the fins cannot increase beyond the boiling point of the liquid while the liquid remains. You could then construct a reflux system to allow the methanol vapors to re-condense and return to the cooling fins. Just another thought!
First, how will the heat be let off. One way is by keeping the system at atmospheric pressure by allowing excess pressure to escape. That would release heat by evaporation (boiling) of the nitrogen. The other way is to keep the system at high pressure to keep all of the nitrogen liquid; the heat would then need to be replaced through a heat exchanger of some sort.
And as for why nitrogen vs. helium, it is much easier to obtain large quantities of liquid nitrogen; liquid helium is more expensive to obtain and requires more-expensive containers to keep it liquid (high pressure) at room temperature.
But since I work in a chemistry laboratory, I have lots of access to liquid N2, but we only have enough liquid He around to cool off the NMR magnets...
Okay, so it might not be too practical for everyone, but I was thinking that you could just submirge the whole motherboard in liquid nitrogen in a good vacuum-insulated container. I would assume that the chemical properties of nitrogen don't change when it's in liquid form, so it would be non-reactive and non-conductive. Then, the only problem is continuously replacing the nitrogen which boils off due to CPU heat (room heat would have little effect in a good insulated container. Any thoughts?
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Actually, whether "sparky" is a real person (which I doubt judging by the lightning through his hand) or not doesn't really seem to matter. He can't be inside the Faraday cage. The fluorescent lightbulb around his head is lit, and as we all learned in Physics 101, there will be a net zero electromagnetic field inside the cage.
The reason that the fluorescent lightbulb is lit is because of the stupidly huge electromagnetic field created OUTSIDE of the Tesla coil. That field will light fluorescent lightbulbs in the vicinity (an area proportional to the square root of the coil power...)
This actually brings up a good point... Tesla himself was a big advocate for using Tesla coils to power people's lights. He even at one point built a tesla coil large enough to light an entire town (I don't remember exactly where it was.) However Tesla coils, while convenient because nobody needs silly things like cords or sockets for their lightbulbs, use up stupid amounts of electricity and are REALLY noisy. The story continues that Tesla finally finished the project, flipped the "big switch" and drew so much power that he shut down the power grids in several states.
Just some nice, Sunday morning, anecdotal remarks.
The story of the .jp box REALLY SCARED THE SH*T OUT OF ME! I'm sure that my box is much more vulnerable than that paranoid .jp box was, and I'm CERTAIN that I would NEVER detect an intrusion such as this. The only way I would not loose sleep over something such as that is knowing that there really is no way that I can prevent it.
On some Linux installations, I have used the BRU 2000 backup software. It costs a couple of hundred $$$, IIRC, but it is really excellent software with many features. So If you are willing to spend some money, that should work for you. I must defer to others, however, in the area of doing it with free tools.
There are a couple of liquids which you might consider for your cooling to avoid the liquid problems. The one I would look strongly at is acetone.
Yes, the stuff smells bad, but it will remain as a liquid (and not get gooey or gelataneous) down much colder than -30 or -40 C... I use dry ice/acetone baths all the time, and it's still very much a liquid at -70C.
It's immiscible with water, so you won't have any water-contamination problems, and any water that hits the cold acetone will instantly freeze.
Although it has a relatively high vapor pressure at room temperature (i.e. it smells bad) the vapor pressure isn't nearly as bad at cold temperatures, and you won't smell it at all. And you won't smell it anyway if you have a cover on the case.
So anyway, you have my vote to use acetone as your cooling fluid.
Here's an idea on silent cooling... evaporation. Evaporation is a exothermic process (gives off heat) and thus is a cooling process. So if you immersed something (like the cooling fins on the CPU) in a cheap liquid with low vapor pressure (perhaps methanol) then the temperature of the fins cannot increase beyond the boiling point of the liquid while the liquid remains. You could then construct a reflux system to allow the methanol vapors to re-condense and return to the cooling fins. Just another thought!
One other thing about mercury... it boils at relatively low temperature, and you just don't want to have to deal with mercury vapor...
Two good points raised.
First, how will the heat be let off. One way is by keeping the system at atmospheric pressure by allowing excess pressure to escape. That would release heat by evaporation (boiling) of the nitrogen. The other way is to keep the system at high pressure to keep all of the nitrogen liquid; the heat would then need to be replaced through a heat exchanger of some sort.
And as for why nitrogen vs. helium, it is much easier to obtain large quantities of liquid nitrogen; liquid helium is more expensive to obtain and requires more-expensive containers to keep it liquid (high pressure) at room temperature.
But since I work in a chemistry laboratory, I have lots of access to liquid N2, but we only have enough liquid He around to cool off the NMR magnets...
Okay, so it might not be too practical for everyone, but I was thinking that you could just submirge the whole motherboard in liquid nitrogen in a good vacuum-insulated container. I would assume that the chemical properties of nitrogen don't change when it's in liquid form, so it would be non-reactive and non-conductive. Then, the only problem is continuously replacing the nitrogen which boils off due to CPU heat (room heat would have little effect in a good insulated container. Any thoughts?