Lord Kelvin's water-drop electrostatic generator

Idiota 17 years ago

"Quanrian" said:
Nice to see more projects popping up.

I guess I have a project running atm as well, so here it goes:

Basically, we're building an electrostatic generator which generates power from falling droplets of water. I expect to see some eyebrows raising, so here it goes:

Chemistry tells us that water contains both H+ and OH- in a perfect balance to create a pH of 7. So when a drop of water falls, it will be neutrally charged. However, even the slightest outside electric interference will cause the pool of water from which the droplets fall to be polarized. This means that a droplet /could/ have slightly more OH- than H+, or vice versa. A charged object would serve the task of creating this interferance just fine. Now I might be losing some of you... but please try to get it. :p Say you have 2 buckets of water at a meter height. Out of the left bucket there falls a positively charged droplet (by chance) into the reservoir beneath it. It passes through a metal ring on it's way, but that doesn't do anything... yet. The point is, you hook the left ring with the right reservoir, and the right ring with the left reservoir. So when the first reservoir becomes positively charged, the ring on the other side will become positively charged, pressing the positively charged ions in the bucket above it further away, which will make a negatively charged droplet drop. This makes the reservoir beneath it negative, which makes it's ring negative, which makes a more positive droplet fall. this cycle will generate thousands of volts until it discharges, which will create a pretty spark to indicate that the generator works.

So that's the theory in a wrap, and unless someone has comments, we got that covered. What I want help with is the following:

How would you be able to tell wich side of the generator turns negative?
How is the randomness of the first charged drop influenced?
Can the circumstances be manipulated so that the right bucket (for example) be negative always? Any more input would be appreciated.

If you didn't understand the theory, look here. [quote="Quanrian"]Nice to see more projects popping up.[/quote] I guess I have a project running atm as well, so here it goes: Basically, we're building an electrostatic generator which generates power from falling droplets of water. I expect to see some eyebrows raising, so here it goes: Chemistry tells us that water contains both H+ and OH- in a perfect balance to create a pH of 7. So when a drop of water falls, it will be neutrally charged. However, even the slightest outside electric interference will cause the pool of water from which the droplets fall to be polarized. This means that a droplet /could/ have slightly more OH- than H+, or vice versa. A charged object would serve the task of creating this interferance just fine. Now I might be losing some of you... but please try to get it. :p Say you have 2 buckets of water at a meter height. Out of the left bucket there falls a positively charged droplet (by chance) into the reservoir beneath it. It passes through a metal ring on it's way, but that doesn't do anything... yet. The point is, you hook the left ring with the right reservoir, and the right ring with the left reservoir. So when the first reservoir becomes positively charged, the ring on the other side will become positively charged, pressing the positively charged ions in the bucket above it further away, which will make a negatively charged droplet drop. This makes the reservoir beneath it negative, which makes it's ring negative, which makes a more positive droplet fall. this cycle will generate thousands of volts until it discharges, which will create a pretty spark to indicate that the generator works. So that's the theory in a wrap, and unless someone has comments, we got that covered. What I want help with is the following: How would you be able to tell wich side of the generator turns negative? How is the randomness of the first charged drop influenced? Can the circumstances be manipulated so that the right bucket (for example) be negative always? Any more input would be appreciated. If you didn't understand the theory, look [url=http://amasci.com/emotor/kelvin.html]here[/url].

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Amarth 17 years ago

"Idiota" said:
How would you be able to tell wich side of the generator turns negative?

Voltmeter? Or, well, the more classic test of rubbing a plastic thing. IIRC it gets positively charged and your cloth will be negative, but might be the other way around. Once charged, take a look to which side it gets attracted, that's negative (or positive if I was wrong all the time)

How is the randomness of the first charged drop influenced?

Randomness is never influenced. In other words, what do you mean?

Can the circumstances be manipulated so that the right bucket (for example) be negative always? Any more input would be appreciated.

Your link has the answer. Start with a slightly positive bucket, it'll attract negative ions. By the time it's evened out, there'll be a surplus of positive charge on the other side and you'll be on your way. I think.

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Idiota 17 years ago

"Amarth" said:
How is the randomness of the first charged drop influenced?
Randomness is never influenced. In other words, what do you mean?

I guess I kind of meant the same as point 3, so yeah.

Anyway, I guess you're right about the piece of cloth, but what I am looking for are objects that wouldn't be the first to spring to mind, but which would theoratically be able to influence which side turns negative. I have to write quite a big report over this, so even the wildest sugestions will be helpful. :p

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Amarth 17 years ago

I dunno. About anything that has a bit of an electric field, I'd say. From Van de Graaff generators to something with moving magnets. Though I don't quite see how to do the last one. You might want to think a bit about Lenz's law.

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E_net4 17 years ago

I expect to see some eyebrows raising

I actually lowered mine, while thinking "Huh, ok..."

And no, I cannot really help on anything.

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Guest1 (guest) 12 years ago

i have a couple of questions because i cant get mine to work:
-is it okay if the water stream is a little thick and choppy?
-is there anything i need to do prior to starting it up? Like drying any wet part of the apparatus or manually charging a specific part?
-does the nozzle have to be far or close to the metal rings?
-how far should the spark gap be from each other?
thank you for your help

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Lord Kelvin's water-drop electrostatic generator

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