Hi folks,

This is a question for people with electrical knowledge, especially in the field of electrostatics. It's also spontaneous. I'm not sure if I'm going to build anything yet.

A few years back I built a Van de Graaff generator. It occurred to me at the time that it would be really cool to transport the electric charge using a liquid instead of a moving belt. I thought of pumping bubbles of electrically charged air into a column of oil and allowing them to rise under gravity. But then I did a few calculations and came to the conclusion that you could barely generate enough current from such a system to build a good generator, so I never built it.

This week I acquired one of these chemical pumps when a laboratory was being cleared out (in the 0.25 kW size):
http://www.schmitt-pumpen.de/en/prod...mp-series.html

So today I was thinking: would it be possible to impart an electric charge to insulating oil (no bubbles this time) and pump the oil up the column of a Van de Graaff generator to transport the charge? If it was all made from transparent acrylic, it would look really cool.

Would it work? How could the oil be charged? Perhaps by pumping it through a stainless gauze connected to a high voltage power supply, I was thinking.

Anyone know? For now, it's just a train of thought. But it's interesting...

All the best,

Chris

Christopher Tidy wrote:

Hi folks,

This is a question for people with electrical knowledge, especially in the
field of electrostatics. It's also spontaneous. I'm not sure if I'm going
to build anything yet.

A few years back I built a Van de Graaff generator. It occurred to me at
the time that it would be really cool to transport the electric charge
using a liquid instead of a moving belt.

The pros in this business built pelletrons. They had chains made of
alternating metal and plastic links, instead of the Van d Graff belt. The
metal links could carry a lot more charge to the HV terminal. They charged
the chain with a modest HV power supply. The biggest in the world was at
Oak Ridge, TN, single-ended with a 50 MV terminal voltage. This one has a
magnet in the terminal that folds the ion path 180 degrees. Many other
tandem Van de Graff machines are straight-through, and have two chains and
the HV terminal is in the middle of the tank. Insulation is sulfur
hexafluoride.

Oil isn't going to carry much charge, unless you dope it with something,
maybe little particles of some polar stuff. Or, maybe, tiny wire fragments.
Then, the charge has to REACH the particles, THROUGH the oil, which I think
wrecks the whole idea. You don't want a very good insulator to interfere
with the charge transfer.

Jon

On Friday, November 27, 2015 at 7:00:48 AM UTC-8, Christopher Tidy wrote:

A few years back I built a Van de Graaff generator. It occurred to me at the time that it would be really cool to transport the electric charge using a liquid instead of a moving belt.

So today I was thinking: would it be possible to impart an electric charge to insulating oil ... and pump the oil up the column of a Van de Graaff generator to transport the charge? If it was all made from transparent acrylic, it would look really cool.

Would it work?

Maybe. Millikan's oil-drop experiment relied on charging oil, but he only got
a handfull of electrons on a droplet.

There are oil-miscible semiconductors, you could flood a bit of your oil tubing with
UV light and create photoconduction for a short period (long enough to
get charge diffusion). The problem, then, is that the charge will repel,
and lie mainly against the tubing walls, which isn't the flowing part of the
oil stream. It seems you'll get charged oil in motion with gravity streams
easier than in pipes.

"Christopher Tidy" wrote in message
...
Hi folks,

This is a question for people with electrical knowledge, especially in
the field of electrostatics. It's also spontaneous. I'm not sure if
I'm going to build anything yet.

A few years back I built a Van de Graaff generator. It occurred to me
at the time that it would be really cool to transport the electric
charge using a liquid instead of a moving belt. I thought of pumping
bubbles of electrically charged air into a column of oil and allowing
them to rise under gravity. But then I did a few calculations and came
to the conclusion that you could barely generate enough current from
such a system to build a good generator, so I never built it.

This week I acquired one of these chemical pumps when a laboratory was
being cleared out (in the 0.25 kW size):
http://www.schmitt-pumpen.de/en/prod...mp-series.html

So today I was thinking: would it be possible to impart an electric
charge to insulating oil (no bubbles this time) and pump the oil up
the column of a Van de Graaff generator to transport the charge? If it
was all made from transparent acrylic, it would look really cool.

Would it work? How could the oil be charged? Perhaps by pumping it
through a stainless gauze connected to a high voltage power supply, I
was thinking.

Anyone know? For now, it's just a train of thought. But it's
interesting...

All the best,

Chris

=============
https://en.wikipedia.org/wiki/Kelvin_water_dropper

-jsw

On Fri, 27 Nov 2015 07:00:38 -0800 (PST), Christopher Tidy
wrote:

Hi folks,

This is a question for people with electrical knowledge, especially in the field of electrostatics. It's also spontaneous. I'm not sure if I'm going to build anything yet.

A few years back I built a Van de Graaff generator. It occurred to me at the time that it would be really cool to transport the electric charge using a liquid instead of a moving belt. I thought of pumping bubbles of electrically charged air into a column of oil and allowing them to rise under gravity. But then I did a few calculations and came to the conclusion that you could barely generate enough current from such a system to build a good generator, so I never built it.

This week I acquired one of these chemical pumps when a laboratory was being cleared out (in the 0.25 kW size):
http://www.schmitt-pumpen.de/en/prod...mp-series.html

So today I was thinking: would it be possible to impart an electric charge to insulating oil (no bubbles this time) and pump the oil up the column of a Van de Graaff generator to transport the charge? If it was all made from transparent acrylic, it would look really cool.

Are you thinking Jacob's Ladder/spark gap? If so, I'd think the
discharges would melt the acrylic tubing in short order.


Would it work? How could the oil be charged? Perhaps by pumping it through a stainless gauze connected to a high voltage power supply, I was thinking.

The oil, I don't think this guy would like it one bit.
http://tinyurl.com/bspfeaa


Anyone know? For now, it's just a train of thought. But it's interesting...

Not a clue. But how would you insulate the motor from the charge in
the first place?

--
Courage and perseverance have a magical talisman, before
which difficulties disappear and obstacles vanish into air.
-- John Quincy Adams

On 11/27/2015 9:00 AM, Christopher Tidy wrote:
Hi folks,

This is a question for people with electrical knowledge, especially in the field of electrostatics. It's also spontaneous. I'm not sure if I'm going to build anything yet.

A few years back I built a Van de Graaff generator. It occurred to me at the time that it would be really cool to transport the electric charge using a liquid instead of a moving belt. I thought of pumping bubbles of electrically charged air into a column of oil and allowing them to rise under gravity. But then I did a few calculations and came to the conclusion that you could barely generate enough current from such a system to build a good generator, so I never built it.

This week I acquired one of these chemical pumps when a laboratory was being cleared out (in the 0.25 kW size):
http://www.schmitt-pumpen.de/en/prod...mp-series.html

So today I was thinking: would it be possible to impart an electric charge to insulating oil (no bubbles this time) and pump the oil up the column of a Van de Graaff generator to transport the charge? If it was all made from transparent acrylic, it would look really cool.

Would it work? How could the oil be charged? Perhaps by pumping it through a stainless gauze connected to a high voltage power supply, I was thinking.

Anyone know? For now, it's just a train of thought. But it's interesting...

All the best,

Chris


About 20 years ago I worked with a physicist, he thought this might
work. So as his tech I proceeded to build a Van de Graaff with oil as
the medium to move the charge, We used a sump pump to pump the oil.
It didn't work on the first try, and there was no attempt to alter
it to make it work. I don't know if he figured out a flaw in the idea,
or, if we decided we needed to go back to money making work. I was
disappointed, it was just dropped with no further thought.
We did use a high voltage power supply as you suggest above.
Mikek

About 20 years ago I worked with a physicist, he thought this might
work. So as his tech I proceeded to build a Van de Graaff with oil as
the medium to move the charge, We used a sump pump to pump the oil.
It didn't work on the first try, and there was no attempt to alter
it to make it work. I don't know if he figured out a flaw in the idea,
or, if we decided we needed to go back to money making work. I was
disappointed, it was just dropped with no further thought.
We did use a high voltage power supply as you suggest above.
Mikek

Hi Mike,

That's interesting to hear that someone has already tried it. I'd be keen to hear a little more about the details of the design and materials, if you can recall them. There might be a fundamental problem, but it might just be a minor design issue which could be resolved.

Best wishes,

Chris

Hi Larry,

Are you thinking Jacob's Ladder/spark gap? If so, I'd think the
discharges would melt the acrylic tubing in short order.

No. I'm thinking of machine which resembles a Van de Graaff generator. There would be a rounded aluminium terminal on the top. Like this:
https://sharepoint.umich.edu/lsa/phy...or_5A50.30.JPG

Not a clue. But how would you insulate the motor from the charge in
the first place?

The parts of the pump which contact the liquid are entirely plastic (PVDF). This is what set me thinking about the idea of a Van de Graaff with pumped oil again (I first thought of the concept with bubbles around 2001).

Chris

Oil isn't going to carry much charge, unless you dope it with something,
maybe little particles of some polar stuff. Or, maybe, tiny wire fragments.
Then, the charge has to REACH the particles, THROUGH the oil, which I think
wrecks the whole idea. You don't want a very good insulator to interfere
with the charge transfer.

Thanks for the thoughts. Why can't oil carry much charge, but a nylon belt can? I don't doubt your answer, but as more of a mechanical guy, I'm not sure of the reason.

A couple of days ago I was thinking that it might be possible to mix the oil with thousands of tiny plastic balls which could carry the charge. Or hollow metal balls, but they might not go through the pump. The pump can cope with a maximum particle size of 3 mm and, depending on the head, can deliver a flow rate up to 60 litres/minute. But charging the balls might be difficult.

Chris

https://en.wikipedia.org/wiki/Kelvin_water_dropper

Interesting. It relies on flow in droplets, though, doesn't it? It's hard to make droplets go upwards. Single air bubbles which bridge a narrow pipe, with short regions of oil in between, might work, but I think the implementation and adjustment would be difficult.

Thanks to everyone for the ideas.

Chris

There are oil-miscible semiconductors, you could flood a bit of your oil tubing with
UV light and create photoconduction for a short period (long enough to
get charge diffusion).

So you mean a semiconducting liquid which can be mixed with oil? Do you have any product names for these semiconductors? If it worked, it could create a nice show.

Chris

On Sat, 28 Nov 2015 05:45:09 -0800 (PST), Christopher Tidy
wrote:

Hi Larry,

Are you thinking Jacob's Ladder/spark gap? If so, I'd think the
discharges would melt the acrylic tubing in short order.

No. I'm thinking of machine which resembles a Van de Graaff generator. There would be a rounded aluminium terminal on the top. Like this:
https://sharepoint.umich.edu/lsa/phy...or_5A50.30.JPG

Not a clue. But how would you insulate the motor from the charge in
the first place?

The parts of the pump which contact the liquid are entirely plastic (PVDF).

Are you sure? I'll bet the seal is against the metal motor shaft.
Plastic wears too quickly. Still, that would give you half an inch of
plastic to insulate _how_ many kV? Seems iffy at best.


This is what set me thinking about the idea of a Van de Graaff with pumped oil again (I first thought of the concept with bubbles around 2001).

Wild concept.

--
Courage and perseverance have a magical talisman, before
which difficulties disappear and obstacles vanish into air.
-- John Quincy Adams

Are you sure? I'll bet the seal is against the metal motor shaft.
Plastic wears too quickly. Still, that would give you half an inch of
plastic to insulate _how_ many kV? Seems iffy at best.

There is no shaft seal. The motor is vertically mounted above the tank and a thick plastic shaft dips down into the liquid.

On Sat, 28 Nov 2015 07:39:56 -0800, Larry Jaques
wrote:

On Sat, 28 Nov 2015 05:45:09 -0800 (PST), Christopher Tidy
wrote:

Hi Larry,

Are you thinking Jacob's Ladder/spark gap? If so, I'd think the
discharges would melt the acrylic tubing in short order.

No. I'm thinking of machine which resembles a Van de Graaff generator. There would be a rounded aluminium terminal on the top. Like this:
https://sharepoint.umich.edu/lsa/phy...or_5A50.30.JPG

Not a clue. But how would you insulate the motor from the charge in
the first place?

The parts of the pump which contact the liquid are entirely plastic (PVDF).

Are you sure? I'll bet the seal is against the metal motor shaft.
Plastic wears too quickly. Still, that would give you half an inch of
plastic to insulate _how_ many kV? Seems iffy at best.


This is what set me thinking about the idea of a Van de Graaff with pumped oil again (I first thought of the concept with bubbles around 2001).

Wild concept.

I've tried to follow the answers you've received regarding oil and
charge, and I'm not certain you're getting correct information.

Dielectrics, permittivity and so on is an aspect of electricity about
which I'm pretty vague, but my recollection is that a
high-permittivity material, like the mineral oil used in oil-filled
capacitors, polarizes easily with a low charge on the opposing plates,
and I would think that equates to a high potential to store an
electrical charge. (or maybe it's irrelevant, because polarization is
not the same thing as storing a charge)

But, as I said, I've always been a little vague about this, being more
interested in the results in a capacitor than in the electric charge
within the dielectric. For example, although there is a high degree of
electrical polarization within the oil, I believe that the net charge
is zero. What that implies for the ability of oil to*store* a charge
is where I'm vague about it.

Sorry if this just confuses the picture. But I think you need to dig
deeper to get the answer you're looking for.

--
Ed Huntress

I've tried to follow the answers you've received regarding oil and
charge, and I'm not certain you're getting correct information.

Dielectrics, permittivity and so on is an aspect of electricity about
which I'm pretty vague, but my recollection is that a
high-permittivity material, like the mineral oil used in oil-filled
capacitors, polarizes easily with a low charge on the opposing plates,
and I would think that equates to a high potential to store an
electrical charge. (or maybe it's irrelevant, because polarization is
not the same thing as storing a charge)

But, as I said, I've always been a little vague about this, being more
interested in the results in a capacitor than in the electric charge
within the dielectric. For example, although there is a high degree of
electrical polarization within the oil, I believe that the net charge
is zero. What that implies for the ability of oil to*store* a charge
is where I'm vague about it.

Thanks for the response, Ed. The way I understand it (and this isn't really my field), you need to either tear electrons out of the oil or force more electrons in, so that a net charge is present in the oil rising up the pipe.. How one achieves that, and how easily it can be done, I'm not sure.

On 11/28/2015 7:38 AM, Christopher Tidy wrote:
About 20 years ago I worked with a physicist, he thought this might
work. So as his tech I proceeded to build a Van de Graaff with oil as
the medium to move the charge, We used a sump pump to pump the oil.
It didn't work on the first try, and there was no attempt to alter
it to make it work. I don't know if he figured out a flaw in the idea,
or, if we decided we needed to go back to money making work. I was
disappointed, it was just dropped with no further thought.
We did use a high voltage power supply as you suggest above.
Mikek

Hi Mike,

That's interesting to hear that someone has already tried it. I'd be keen to hear a little more about the details of the design and materials, if you can recall them. There might be a fundamental problem, but it might just be a minor design issue which could be resolved.

Best wishes,

Chris


Ya, I don't remember much. We used pvc riser tube, about 4 ft tall.
A possible power supply was 12kV, I don't recall, but I know we had
those on the shelf. I think we used a stainless steel bowl as the
accumulator. Sorry can't give you much info.
Mikek

Ya, I don't remember much. We used pvc riser tube, about 4 ft tall.
A possible power supply was 12kV, I don't recall, but I know we had
those on the shelf. I think we used a stainless steel bowl as the
accumulator. Sorry can't give you much info.
Mikek

It's a pity that your boss never published the details of the test. Do you recall how you attempted to transfer the charge to the oil, and how fast the oil moved? I'm assuming it was transformer oil you used.

Thanks!

Chris

On Sat, 28 Nov 2015 07:46:00 -0800 (PST), Christopher Tidy
wrote:

Are you sure? I'll bet the seal is against the metal motor shaft.
Plastic wears too quickly. Still, that would give you half an inch of
plastic to insulate _how_ many kV? Seems iffy at best.

There is no shaft seal. The motor is vertically mounted above the tank and a thick plastic shaft dips down into the liquid.

OK, if you say so, that's handled.

How you make a natural insulator (oil) into a carrier for electrons is
your next very interesting task. Let us know what you find. (Too bad
Mike's guy didn't pursue it.)

--
Courage and perseverance have a magical talisman, before
which difficulties disappear and obstacles vanish into air.
-- John Quincy Adams

Christopher Tidy wrote:

Oil isn't going to carry much charge, unless you dope it with something,
maybe little particles of some polar stuff. Or, maybe, tiny wire
fragments. Then, the charge has to REACH the particles, THROUGH the oil,
which I think
wrecks the whole idea. You don't want a very good insulator to interfere
with the charge transfer.

Thanks for the thoughts. Why can't oil carry much charge, but a nylon belt
can? I don't doubt your answer, but as more of a mechanical guy, I'm not
sure of the reason.

A couple of days ago I was thinking that it might be possible to mix the
oil with thousands of tiny plastic balls which could carry the charge. Or
hollow metal balls, but they might not go through the pump. The pump can
cope with a maximum particle size of 3 mm and, depending on the head, can
deliver a flow rate up to 60 litres/minute. But charging the balls might
be difficult.
Yes, I think you are on the right track. I'm not a physicist, but it seems
that a liquid just isn't going to carry much charge. i think it is SURFACES
that can carry charge, and these surfaces have to have a distinctly
different polarity than what they are surrounded by. Anything works OK if
surrounded by vacuum (or air, even). The oil would have to be a VERY good
insulator, meaning very clean and dry. The metal balls ought to work, you'd
need a metal brush to break through the oil film to charge them.

Jon

On Sat, 28 Nov 2015 08:26:55 -0800 (PST), Christopher Tidy
wrote:

I've tried to follow the answers you've received regarding oil and
charge, and I'm not certain you're getting correct information.

Dielectrics, permittivity and so on is an aspect of electricity about
which I'm pretty vague, but my recollection is that a
high-permittivity material, like the mineral oil used in oil-filled
capacitors, polarizes easily with a low charge on the opposing plates,
and I would think that equates to a high potential to store an
electrical charge. (or maybe it's irrelevant, because polarization is
not the same thing as storing a charge)

But, as I said, I've always been a little vague about this, being more
interested in the results in a capacitor than in the electric charge
within the dielectric. For example, although there is a high degree of
electrical polarization within the oil, I believe that the net charge
is zero. What that implies for the ability of oil to*store* a charge
is where I'm vague about it.

Thanks for the response, Ed. The way I understand it (and this isn't really my field), you need to either tear electrons out of the oil or force more electrons in, so that a net charge is present in the oil rising up the pipe. How one achieves that, and how easily it can be done, I'm not sure.

Same here. d8-)

--
Ed Huntress

Christopher Tidy wrote:

https://en.wikipedia.org/wiki/Kelvin_water_dropper

Interesting. It relies on flow in droplets, though, doesn't it? It's hard
to make droplets go upwards. Single air bubbles which bridge a narrow
pipe, with short regions of oil in between, might work, but I think the
implementation and adjustment would be difficult.

Thanks to everyone for the ideas.

Chris
Well, I think there might be a way to make it work with pumped oil. But, as
I mentioned before, charge is usually stored on SURFACES. So, if you mixed
air with the oil, so it was a stream of bubbles in the oil, that might
enable it to carry charge. You could use metal screens that the oil/air mix
flowed through to inject/extract the charge.

Jon

In article ,
Christopher Tidy wrote:

About 20 years ago I worked with a physicist, he thought this might
work. So as his tech I proceeded to build a Van de Graaff with oil as
the medium to move the charge, We used a sump pump to pump the oil.
It didn't work on the first try, and there was no attempt to alter
it to make it work. I don't know if he figured out a flaw in the idea,
or, if we decided we needed to go back to money making work. I was
disappointed, it was just dropped with no further thought.
We did use a high voltage power supply as you suggest above.
Mikek

Hi Mike,

That's interesting to hear that someone has already tried it. I'd be keen to
hear a little more about the details of the design and materials, if you can
recall them. There might be a fundamental problem, but it might just be a
minor design issue which could be resolved.

My suspicion is that oil isn't a good enough insulator, especially in
practice with a pinch of dirt and water in it.

Joe Gwinn

On Sat, 28 Nov 2015 08:26:55 -0800 (PST), Christopher Tidy
wrote:

I've tried to follow the answers you've received regarding oil and
charge, and I'm not certain you're getting correct information.

Dielectrics, permittivity and so on is an aspect of electricity about
which I'm pretty vague, but my recollection is that a
high-permittivity material, like the mineral oil used in oil-filled
capacitors, polarizes easily with a low charge on the opposing plates,
and I would think that equates to a high potential to store an
electrical charge. (or maybe it's irrelevant, because polarization is
not the same thing as storing a charge)

But, as I said, I've always been a little vague about this, being more
interested in the results in a capacitor than in the electric charge
within the dielectric. For example, although there is a high degree of
electrical polarization within the oil, I believe that the net charge
is zero. What that implies for the ability of oil to*store* a charge
is where I'm vague about it.

Thanks for the response, Ed. The way I understand it (and this isn't really my field), you need to either tear electrons out of the oil or force more electrons in, so that a net charge is present in the oil rising up the pipe. How one achieves that, and how easily it can be done, I'm not sure.

You folks should explore the term "EDM" a bit

Gunner

On Sat, 28 Nov 2015 09:47:15 -0800, Gunner Asch
wrote:

On Sat, 28 Nov 2015 08:26:55 -0800 (PST), Christopher Tidy
wrote:

I've tried to follow the answers you've received regarding oil and
charge, and I'm not certain you're getting correct information.

Dielectrics, permittivity and so on is an aspect of electricity about
which I'm pretty vague, but my recollection is that a
high-permittivity material, like the mineral oil used in oil-filled
capacitors, polarizes easily with a low charge on the opposing plates,
and I would think that equates to a high potential to store an
electrical charge. (or maybe it's irrelevant, because polarization is
not the same thing as storing a charge)

But, as I said, I've always been a little vague about this, being more
interested in the results in a capacitor than in the electric charge
within the dielectric. For example, although there is a high degree of
electrical polarization within the oil, I believe that the net charge
is zero. What that implies for the ability of oil to*store* a charge
is where I'm vague about it.

Thanks for the response, Ed. The way I understand it (and this isn't really my field), you need to either tear electrons out of the oil or force more electrons in, so that a net charge is present in the oil rising up the pipe. How one achieves that, and how easily it can be done, I'm not sure.

You folks should explore the term "EDM" a bit

Gunner

I don't think that will help. That was my specialty, at American
Machinist and at Sodick, and I've probably read all of the papers.
It's a straighforward capacitor situation until it becomes ionized and
permits a spark.

I don't recall any suggestion that the oil dielectric carried a charge
itself.

--
Ed Huntress

Yes, I think you are on the right track. I'm not a physicist, but it seems
that a liquid just isn't going to carry much charge. i think it is SURFACES
that can carry charge, and these surfaces have to have a distinctly
different polarity than what they are surrounded by. Anything works OK if
surrounded by vacuum (or air, even). The oil would have to be a VERY good
insulator, meaning very clean and dry. The metal balls ought to work, you'd
need a metal brush to break through the oil film to charge them.

Hmmm. Conductive rubber balls might work, if they're the right density and small enough to pass through the pump. Actually, I don't think they need to be very conductive because of the high voltage and low current. Slightly conductive would be enough.

It would be interesting to know how quickly the charge spreads to the outer surface of the oil column. Too fast to pump it up beforehand, I suspect.

Chris

Well, I think there might be a way to make it work with pumped oil. But, as
I mentioned before, charge is usually stored on SURFACES. So, if you mixed
air with the oil, so it was a stream of bubbles in the oil, that might
enable it to carry charge. You could use metal screens that the oil/air mix
flowed through to inject/extract the charge.

Interesting thought. It might be possible to create a churning mixture of oil and air.

You folks should explore the term "EDM" a bit

As in electrical discharge machining?

My suspicion is that oil isn't a good enough insulator, especially in
practice with a pinch of dirt and water in it.

This could be true. I need to find figures for the resistivity of used transformer oil. I can make sure it's visually clean, but clean room standards won't apply.

On Sat, 28 Nov 2015 10:17:45 -0800 (PST), Christopher Tidy
wrote:

You folks should explore the term "EDM" a bit

As in electrical discharge machining?

Ayup. High voltage done in oil....

Gunner Asch fired this volley in
:


Ayup. High voltage done in oil....

But not even similar in the process, Gunner. The oil is used strictly as a
dielectric, not as a carrier of the charge. When the dielectric breaks
down is when the discharge spark occurs.

Lloyd

"Christopher Tidy" wrote in message
...
About 20 years ago I worked with a physicist, he thought this might
work. So as his tech I proceeded to build a Van de Graaff with oil
as
the medium to move the charge, We used a sump pump to pump the oil.
It didn't work on the first try, and there was no attempt to alter
it to make it work. I don't know if he figured out a flaw in the
idea,
or, if we decided we needed to go back to money making work. I was
disappointed, it was just dropped with no further thought.
We did use a high voltage power supply as you suggest above.
Mikek

Hi Mike,

That's interesting to hear that someone has already tried it. I'd be
keen to hear a little more about the details of the design and
materials, if you can recall them. There might be a fundamental
problem, but it might just be a minor design issue which could be
resolved.

Best wishes,

Chris

==========

https://en.wikipedia.org/wiki/Electrohydrodynamics

http://www.dtic.mil/dtic/tr/fulltext/u2/740551.pdf

-jsw

On Sat, 28 Nov 2015 12:57:31 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
:


Ayup. High voltage done in oil....

But not even similar in the process, Gunner. The oil is used strictly as a
dielectric, not as a carrier of the charge. When the dielectric breaks
down is when the discharge spark occurs.

Lloyd

Indeed. Now tell me how oil is going to carry that charge...

On Saturday, November 28, 2015 at 6:07:17 AM UTC-8, Christopher Tidy wrote:
There are oil-miscible semiconductors, you could flood a bit of your oil tubing with
UV light and create photoconduction...

So you mean a semiconducting liquid which can be mixed with oil? Do you have any product names for these semiconductors? If it worked, it could create a nice show.

Tweak, Cramolin blue/Caig DeOxit, Stabilant-22A and -22L, and US patent #4696832
are all variants on this theme. End-user products have lots of other ingredients, and some
are soap/alcohol/grease mixtures (used to be chlorinated hydrocarbons).

On Saturday, November 28, 2015 at 10:18:59 AM UTC-8, Christopher Tidy wrote:
My suspicion is that oil isn't a good enough insulator, especially in
practice with a pinch of dirt and water in it.

This could be true. I need to find figures for the resistivity of used transformer oil. I can make sure it's visually clean, but clean room standards won't apply.

Insulating oils (I've used Shell Diala AX) are inexpensive. Just buy a can.
Used oil, presumably, is recycled (re-refined), and won't be easy to locate.

On Sat, 28 Nov 2015 12:13:02 -0800, Gunner Asch
wrote:

On Sat, 28 Nov 2015 12:57:31 -0600, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
m:


Ayup. High voltage done in oil....

But not even similar in the process, Gunner. The oil is used strictly as a
dielectric, not as a carrier of the charge. When the dielectric breaks
down is when the discharge spark occurs.

Lloyd

Indeed. Now tell me how oil is going to carry that charge...

The oil itself doesn't carry the charge. When the oil breaks down from
the voltage it creates an ionized channel -- a plasma, actually -- and
that carries the charge between the electrode and the work.

--
Ed Huntress

Gunner Asch fired this volley in
news
Indeed. Now tell me how oil is going to carry that charge...

Um... you seemed to be saying in your initial post that EDM would somehow
give a 'clue' as to how to do this.

_I_ was saying that EDM only proves it WON'T work.

Lloyd

"Christopher Tidy" wrote in message
...
Well, I think there might be a way to make it work with pumped oil.
But, as
I mentioned before, charge is usually stored on SURFACES. So, if
you mixed
air with the oil, so it was a stream of bubbles in the oil, that
might
enable it to carry charge. You could use metal screens that the
oil/air mix
flowed through to inject/extract the charge.

Interesting thought. It might be possible to create a churning
mixture of oil and air.

http://www.machinerylubrication.com/...arge-hydraulic

-jsw

On Saturday, November 28, 2015 at 8:45:12 AM UTC-5, Christopher Tidy wrote:

No. I'm thinking of machine which resembles a Van de Graaff generator. There would be a rounded aluminium terminal on the top. Like this:
https://sharepoint.umich.edu/lsa/phy...or_5A50.30.JPG


Chris

How about inverting the generator so you could charge drops of oil and they would fall to the rounded aluminium terminal.

Dan

On Saturday, November 28, 2015 at 5:28:33 PM UTC-5, wrote:
On Saturday, November 28, 2015 at 8:45:12 AM UTC-5, Christopher Tidy wrote:

No. I'm thinking of machine which resembles a Van de Graaff generator. There would be a rounded aluminium terminal on the top. Like this:
https://sharepoint.umich.edu/lsa/phy...or_5A50.30.JPG


Chris

How about inverting the generator so you could charge drops of oil and they would fall to the rounded aluminium terminal.

Dan

Never mind http://amasci.com/emotor/kelvin.html

Dan

On Sat, 28 Nov 2015 12:24:41 -0800 (PST), whit3rd
wrote:

On Saturday, November 28, 2015 at 10:18:59 AM UTC-8, Christopher Tidy wrote:
My suspicion is that oil isn't a good enough insulator, especially in
practice with a pinch of dirt and water in it.

This could be true. I need to find figures for the resistivity of used transformer oil. I can make sure it's visually clean, but clean room standards won't apply.

Insulating oils (I've used Shell Diala AX) are inexpensive. Just buy a can.
Used oil, presumably, is recycled (re-refined), and won't be easy to locate.

Talk to any EDM shop. Bring a bucket.
And donuts