Scientist please confirm!?!

[zooter]

The modern equivalent to playing with matches.

Camera flash is basically a capacitor that discharges through a bulb in a controlled fashion. I hear you can make firecrackers of some serious bang by taking the capacitor and shorting it instead. Take an eye out pretty easily too.

[Filterer]

Other wise another great use for them is to charge them up and use them as a cattle prod on people!

[Fooman]

It will be bloody a lot more than 500ma!!!
My tutor at uni got a wacking great capacitor from somewhere, one as big as a bucket, more that a foot high. He charged it up, put a big screwdriver with a shaft about 1cm thick across the points (rigged up a string-operated thing so he could do it from 20m or so away) and it VAPOURISED the screwdriver. There was a massive flash and bang and there was only a charred handle left. Cool. Drifting green smoke. Or maybe that was just the afterimage of the flash.
Ask Lard Embargo, he knows, he built his own tesla coil.

Many moons ago during a 1st year physics paper, the lecturer (Andre von Biel - was actually a Prussian count I think) did a similar thing - he trundled out this huge transformer and capacitor on a trolley, and proceeded to charge the capacitor at 1000 V with 1000 J of energy (E = 1/2 x V x Q), so Q = 2 Coulombs or so - meaning the capacitor had a capacitance of 0.002 Farads or so - pretty big!

He the proceeded to discharge it through a length of wire in a millisecond or so meaning there was on average 1 000 000 watts (or a megawatt, or ~ 1330 hp) going through this little wire, which suddenly decided to vapourise with a sound like a gun going off...scared the shit out of those not paying attention or asleep (class of 200 or so).

Strange character, Dr von Biel - he used the skin of his dead cat to generate static electricity for demonstrations...

Cheers,
FM

[limbimtimwim]

I think some have not watched and listened to the first video carefully enough.

In the first video the proposed technology is not:
"Use a capacitor to build up a big charge and then use that to zap a bucket of water"

I can't see how that would be more efficient than conventional hydrogen production methods, so I guess that isn't very useful.

The proposal is:
"Use water as the Dielectric in a capacitor".

So it appears if you build up the charge enough (And gently) that when your dielectric (The water) suddenly starts conducting electricity, it explodes (How violently, I wonder..) and breaks down into hydrogen and oxygen.

The electricity input into the capacitor can be reused, it was released when the water ceased to store the current. It was still a capacitor, right?

That's clever. If it actually works.

[Jantar]

So it appears if you build up the charge enough (And gently) that when your dielectric (The water) suddenly starts conducting electricity, it explodes (How violently, I wonder..) and breaks down into hydrogen and oxygen.

The electricity input into the capacitor can be reused, it was released when the water ceased to store the current. It was still a capacitor, right?
.

When the di-electric (water) breaksdown and starts conducting electricity the water is converted to hydrogen and oxygen. The explosion is the hydrogen and oxygen recombining to form water (steam), and the amount of heat energy given off is the same or less than the electrical energy put in. You still dont get anything for nothing.

[Street Gerbil]

Overcharging an electrolyte capacitor is cool too. It says hissssss... wham! And aluminum foil flies in every direction. Spectacular.

[limbimtimwim]

When the di-electric (water) breaksdown and starts conducting electricity the water is converted to hydrogen and oxygen. The explosion is the hydrogen and oxygen recombining to form water (steam), and the amount of heat energy given off is the same or less than the electrical energy put in. You still dont get anything for nothing.

I don't think you watched the first video, the guy doesn't talk about using heat. Capturing the hydrogen is the aim of the game. The question is: Is it more efficient than electrolysis? Chances are as I'm sure you will agree, slim.

[The Stranger:Me]

You are telling me, and whats more the release of that energy can be very spectacular
:

Being a gentleman precludes me from speculating on this one.

Meh.......little smoke filled tubes are nothing to be afraid of even when they start leaking..........vaccuum cleaners that let out their smoke are to be respected! You would not believe how much smoke one of them babies can hold

What exactly was Mark doing with the vaccuum cleaner at the time, did he have something stuck in it?

[JeremyW]

Capacitors are awesome to blow up.... but then they smell like cat piss

[Jantar]

No, I haven't watched either video. I can't watch them at work, and on dial up its too slow at home. But that doesn't alter the science that you can't get anything for nothing.

Put simply: If you pass an electric current through water, you will get Hydrogen formed at the anode, and Oxygen at the cathode. As long as these two points are seperated and there is no path by which the two gasses can recombine, then the two gasses can be collected. You will get 2 H2 molecules and 1 O2 Molecule for every 2 electrons passed. The amount of current that can be passed through the water depends on the resitance of the water and the applied voltage. Pure water needs a high voltage to obtain much current, but that situation can be improved by adding a catalyst (eg dilute H2SO4). What the capacitor does is allow the voltage to increase to the point where the di-electric breaks down and hence a large current is passed over a short period of time. The gasses are formed, and if they are far enough apart with no possibility of recombining then they can be collected, the capacitor would be discharged, then as more water flows between the plates the di-electric strength would be restored and the process would repeat. But if the gasses are permitted to combine then they will explode, and the heat given off in the explosion will be almost equal to the electrical energy used to seperate the gasses in the first place.

Conservation of energy and conservation of mass is maintained.

[limbimtimwim]

Most-everyone knows electrolysis creates hydrogen.

Just watch the video or google "Stanley Meyer". You misunderstand, Mr Meyer was not proposing using a separate capacitor, it was using the water as a component in one.

[Jantar]

... You misunderstand, Mr Meyer was not proposing using a separate capacitor, it was using the water as a component in one.

Yes, that is what I understood you to say. The water would be the dielectric, but that still doesn't alter the basic science (both physics and chemistry).

[dhunt]

You are telling me, and whats more the release of that energy can be very spectacular

All I know is that if you hook up a little electrolytic capacitor (One of the little ones made of tin foil) to a 230V light bulb and wait for the owner to turn the light on the results are very impressive.

[SlashWylde]

Can I use one of those big capacitors you get from an old CRT monitor?

Unless one is an experienced electronics tech or engineer I wouldn't go messing around with anything from the inside of a TV or PC monitor. There are high AC and DC voltages present when a CRT is running (many thousands of volts) and there can be stored potentials of more than one thousand volts DC even after the unit is switched off. These voltages can kill immediately on contact.

Even rapid discharges of low voltage caps can be dangerous due to vapourising metal and hot electrolyte. Good way to get a nasty burn or lose an eye.

Be careful

[degrom]

Unless one is an experienced electronics tech or engineer I wouldn't go messing around with anything from the inside of a TV or PC monitor. There are high AC and DC voltages present when a CRT is running (many thousands of volts) and there can be stored potentials of more than one thousand volts DC even after the unit is switched off. These voltages can kill immediately on contact.

Even rapid discharges of low voltage caps can be dangerous due to vapourising metal and hot electrolyte. Good way to get a nasty burn or lose an eye.

Be careful

Was only kiding,there is a reason they put Warning signs on the back of those devices.