Developing HV DC Pulses...

[Phil Hobbs]

Lamont Cranston <amdx62@gmail.com> wrote:

On Saturday, May 13, 2023 at 5:09:13 PM UTC-5, Phil Hobbs wrote:
Lamont Cranston <amd...@gmail.com> wrote:
On Saturday, May 13, 2023 at 4:43:25 PM UTC-5, Phil Hobbs wrote:

A quarter-inch square copper patch, 0.062 thick FR4, would be about 1
pF. At, say, 500 volts/mil, that\'s about 30 KV to the other side.

A clever design could be hacked onto a 1\"x2\" slab. Maybe go 10,000:1
(discrete 10 nF cap) and include a BNC to go directly to the scope.


You have to worry about corona from the edges, especially if they\'re
square. I\'d be looking at ignition cable with a bit of solid wire
wrapped round it, a few inches from one end.

5 to 6 turns of #20 wire on a 1/4\" HV wire is 1pf.

Press on, next problem.

--
Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC /
Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

 

[Lamont Cranston]

On Saturday, May 13, 2023 at 8:09:57 PM UTC-5, Phil Hobbs wrote:

5 to 6 turns of #20 wire on a 1/4\" HV wire is 1pf.


Press on, next problem.

Sure thing!
Give me some hints on how to minimize corona.
Other than no sharp points.
Tomorrow I\'m building a voltage divider to supply four vessels, dropping the voltage by 25% at each step.
I have five 1\" porcelain standoffs that I was going to mount on a Lexan strip. I\'m using two 1.5MΩ for each section.
So, 12MΩ total. The HV wire that goes to the 4 vessels will attach to the Porcelain standoffs.
Do I want to minimize resistor lead lengths, i.e. put the standoffs closer together?
Or, do I want the Four- 14\" HV wires going to each vessel spaced apart, put the standoffs farther apart?
This will be 2 quick tests to see if results are linear with voltage or if at some voltage you have diminishing returns.
1, 2, 3, and 4kV and 5, 6, 7, and 8kV.
Mikek

 

[whit3rd]

On Saturday, May 13, 2023 at 7:31:00 PM UTC-7, Lamont Cranston wrote:

On Saturday, May 13, 2023 at 8:09:57 PM UTC-5, Phil Hobbs wrote:

5 to 6 turns of #20 wire on a 1/4\" HV wire is 1pf.


Press on, next problem.
Sure thing!
Give me some hints on how to minimize corona.
Other than no sharp points.

images.google.com has a load of examples of \"HV wiring corona ring\" and
some of \'em are just twists of wire.

At irregularities (like splices or joints) the field adjacent to the pointy is much lessened
if you put the same HV on an encircling tube or spring-like item

<https://www.huanengfitting.com/news/corona-ring-purpose-the-ultimate-faq-guide.html>

At 20 kV, outer diameter of uninsulated wire bits should be large (8mm?) like auto
spark plug wires\' insulation. It\'s OK if all the current flows in a tiny wire inside. As long
as the outer shielding loop (or cylinder, ring, ball) is connected to the same HV as the wire,
there\'s zero field in the gap (and thus, at the pointy places).

 

[John Walliker]

On Saturday, 13 May 2023 at 22:01:26 UTC+1, ehsjr wrote:

On 5/13/2023 12:37 PM, Lamont Cranston wrote:
On Saturday, May 13, 2023 at 10:55:03 AM UTC-5, John Larkin wrote:
On Sat, 13 May 2023 08:07:17 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Saturday, May 13, 2023 at 8:50:52?AM UTC-5, John Larkin wrote:
On Fri, 12 May 2023 23:42:50 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Friday, May 12, 2023 at 10:13:12?PM UTC-5, John Larkin wrote:

Where\'s Sloman\'s design? I really wanted to see that.

Here\'s a suggestion.

https://www.dropbox.com/s/lm7aqo3e3892hhb/6BK4_Pulser_1.jpg?raw=1

It needs to be tested and maybe tweaked. I haven\'t designed with tubes
lately.

Ahh, great John, I have been looking at grounded grid schematics, but not with your twist.
Now, I\'m waiting for parts.
I thought it was cute to have a single 6-volt power supply, but that
nails the positive grid (I keep wanting to say gate) drive at 6 too.

Whit\'s idea of push-pull drive is cute but needs another power supply,
and in its most basic form forces the + and - grid voltages to be
equal, although that is probably OK and easily fixed. One 556, the
dual 555, could drive both the grid and the cathode.

I\'m already thinking about two neon sign transformers, and another
complete tube switcher, with opposite polarity, so it will ą 7kV for a 14KV differential.

I was thinking the differential to get higher voltage, in the end I would like to have 30kV,
whether that is single sided or ± I don\'t know what is best.

The oil emulsion thing is inherently AC-coupled, no? One supply and
one tube does that.

And one neon sign transformer could make +-HV if you really wanted
that.


Would we build a negative switcher or to positives and invert the input to one?
I think Whit\'s idea is to drive the grid and cathode of the one tube,
0 and +12 maybe, antiphase. Not to have pos and neg HV.

I don\'t understand that.

My suggested circuit works well making low duty cycle negative HV
pulses. Positive-going pulses would be harder.

OK, I think that is a logic thing. Since the circuit is acting to bring the output to 0V,
you are calling that negative HV pulses?



You should build in the scope pickoff, so you can see what\'s going on.
We usually build in a signal pickoff/monitor circuit on pulsers.

Agree on that, Need to source a 1nF HV cap.
Make it!

Ya, I already looked at dielectric breakdown voltages, it seems it takes a thick dielectric.

A 1\" long copper pipe with a 0.25\" copper pipe in the center is 2pf.
If I fill it with silicone sealer (~3) I\'m up to 6pf and can shorten it considerably.

Is silicone sealer better than air for breakdown voltage?
Teflon tape is what I\'d use. (6000 V/mil according to American
Durafilm) Wrap the center conductor with multiple layers so
that it fits snugly in the outer pipe.
Ed

Kapton tape has much better dielectric strength and it comes with adhesive as well!
John

 

[Lamont Cranston]

On Sunday, May 14, 2023 at 4:10:16 AM UTC-5, John Walliker wrote:

Kapton tape has much better dielectric strength and it comes with adhesive as well!
John

My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV..,
But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
He wants to use banana plugs for quick change.
Can we get away with this?
https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
Would it help to cover the Resistor divider with a few layers of Kaptan tape?
Thanks, Mikek

 

[Lamont Cranston]

On Sunday, May 14, 2023 at 7:31:03 AM UTC-5, Lamont Cranston wrote:

On Sunday, May 14, 2023 at 4:10:16 AM UTC-5, John Walliker wrote:

Kapton tape has much better dielectric strength and it comes with adhesive as well!
John
My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
He wants to use banana plugs for quick change.
Can we get away with this?
https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
Would it help to cover the Resistor divider with a few layers of Kaptan tape?
Thanks, Mikek

Amazon has these HV banana jacks and plugs, seller says rated for 10kV.
https://www.amazon.com/White-Banana-Voltage-Connectors-Sockets/dp/B0BX9TGJHF/ref=sr_1_13?crid=2HTJKRKG8DOYN&keywords=High+Voltage+Banana+jacks&qid=1684067714&s=hi&sprefix=high+voltage+banana+jacks%2Ctools%2C160&sr=1-13
HV cable should fit inside of them, seems like a good idea!

 

[Lamont Cranston]

On Sunday, May 14, 2023 at 7:48:34 AM UTC-5, Lamont Cranston wrote:

On Sunday, May 14, 2023 at 7:31:03 AM UTC-5, Lamont Cranston wrote:
On Sunday, May 14, 2023 at 4:10:16 AM UTC-5, John Walliker wrote:

Kapton tape has much better dielectric strength and it comes with adhesive as well!
John

Looking at Kaptan tape, I find 7500V per mil, if I cover the voltage divider with a couple
of layers of Kaptan Tape will that prevent corona?
Thanks, Mikek

 

[John Larkin]

On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:

Kapton tape has much better dielectric strength and it comes with adhesive as well!
John

My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
He wants to use banana plugs for quick change.
Can we get away with this?
https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
Would it help to cover the Resistor divider with a few layers of Kaptan tape?
Thanks, Mikek

Put a row of banana jacks on a piece of plastic. Solder the resistors
between the jacks the obvious way. Ordinary banana leads can run out
to the cells. Ignore corona. It\'s only an experiment and it\'s only
8KV.

Amazon has great banana jack assortments.

https://www.amazon.com/gp/product/B07KCRMV4V/

https://www.amazon.com/gp/product/B01CJDGWRU

These are cool on PC boards too.

 

[John Larkin]

On Sun, 14 May 2023 05:48:30 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

On Sunday, May 14, 2023 at 7:31:03?AM UTC-5, Lamont Cranston wrote:
On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:

Kapton tape has much better dielectric strength and it comes with adhesive as well!
John
My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
He wants to use banana plugs for quick change.
Can we get away with this?
https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
Would it help to cover the Resistor divider with a few layers of Kaptan tape?
Thanks, Mikek

Amazon has these HV banana jacks and plugs, seller says rated for 10kV.
https://www.amazon.com/White-Banana-Voltage-Connectors-Sockets/dp/B0BX9TGJHF/ref=sr_1_13?crid=2HTJKRKG8DOYN&keywords=High+Voltage+Banana+jacks&qid=1684067714&s=hi&sprefix=high+voltage+banana+jacks%2Ctools%2C160&sr=1-13
HV cable should fit inside of them, seems like a good idea!

Gross overkill at 8KV.

As I keep telling my engineers, keep it simple and get it done.

 

[Lamont Cranston]

On Sunday, May 14, 2023 at 8:15:40 AM UTC-5, John Larkin wrote:

On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:

Kapton tape has much better dielectric strength and it comes with adhesive as well!
John

My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
He wants to use banana plugs for quick change.
Can we get away with this?
https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
Would it help to cover the Resistor divider with a few layers of Kaptan tape?
Thanks, Mikek
Put a row of banana jacks on a piece of plastic. Solder the resistors
between the jacks the obvious way. Ordinary banana leads can run out
to the cells. Ignore corona. It\'s only an experiment and it\'s only
8KV.

Amazon has great banana jack assortments.

https://www.amazon.com/gp/product/B07KCRMV4V/

https://www.amazon.com/gp/product/B01CJDGWRU

These are cool on PC boards too.

John, I\'ll take that under advisement, however,
there could come a point in experiments, that I add a second transformer
and go up to 18kV or even 30kV. When we go to a larger diameter vessel,
the electric field per cm goes down, to compensate our input voltage needs to go up.
I\'m now hopefully going to start spending someone else\'s money on parts, so I have less concern.
I\'d like to build for possible future developments.
What about kaptan tape over the Resistive divider, does that help prevent corona?
Mikek

P.S. adding in my ignorance about HV projects, I\'d rather err on the side of gross overkill!

 

[John Larkin]

On Sun, 14 May 2023 06:27:38 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

On Sunday, May 14, 2023 at 8:15:40?AM UTC-5, John Larkin wrote:
On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:

Kapton tape has much better dielectric strength and it comes with adhesive as well!
John

My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
He wants to use banana plugs for quick change.
Can we get away with this?
https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
Would it help to cover the Resistor divider with a few layers of Kaptan tape?
Thanks, Mikek
Put a row of banana jacks on a piece of plastic. Solder the resistors
between the jacks the obvious way. Ordinary banana leads can run out
to the cells. Ignore corona. It\'s only an experiment and it\'s only
8KV.

Amazon has great banana jack assortments.

https://www.amazon.com/gp/product/B07KCRMV4V/

https://www.amazon.com/gp/product/B01CJDGWRU

These are cool on PC boards too.

John, I\'ll take that under advisement, however,
there could come a point in experiments, that I add a second transformer
and go up to 18kV or even 30kV. When we go to a larger diameter vessel,
the electric field per cm goes down, to compensate our input voltage needs to go up.
I\'m now hopefully going to start spending someone else\'s money on parts, so I have less concern.
I\'d like to build for possible future developments.
What about kaptan tape over the Resistive divider, does that help prevent corona?
Mikek

P.S. adding in my ignorance about HV projects, I\'d rather err on the side of gross overkill!

If you do simple stuff fast, you\'ll learn more.

 

[Lasse Langwadt Christensen]

søndag den 14. maj 2023 kl. 16.04.00 UTC+2 skrev John Larkin:

On Sun, 14 May 2023 06:27:38 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 8:15:40?AM UTC-5, John Larkin wrote:
On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:

Kapton tape has much better dielectric strength and it comes with adhesive as well!
John

My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
He wants to use banana plugs for quick change.
Can we get away with this?
https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
Would it help to cover the Resistor divider with a few layers of Kaptan tape?
Thanks, Mikek
Put a row of banana jacks on a piece of plastic. Solder the resistors
between the jacks the obvious way. Ordinary banana leads can run out
to the cells. Ignore corona. It\'s only an experiment and it\'s only
8KV.

Amazon has great banana jack assortments.

https://www.amazon.com/gp/product/B07KCRMV4V/

https://www.amazon.com/gp/product/B01CJDGWRU

These are cool on PC boards too.

John, I\'ll take that under advisement, however,
there could come a point in experiments, that I add a second transformer
and go up to 18kV or even 30kV. When we go to a larger diameter vessel,
the electric field per cm goes down, to compensate our input voltage needs to go up.
I\'m now hopefully going to start spending someone else\'s money on parts, so I have less concern.
I\'d like to build for possible future developments.
What about kaptan tape over the Resistive divider, does that help prevent corona?
Mikek

P.S. adding in my ignorance about HV projects, I\'d rather err on the side of gross overkill!


If you do simple stuff fast, you\'ll learn more.

too expensive, too late, or .. good enough

 

[John Larkin]

On Sun, 14 May 2023 07:07:00 -0700 (PDT), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

søndag den 14. maj 2023 kl. 16.04.00 UTC+2 skrev John Larkin:
On Sun, 14 May 2023 06:27:38 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 8:15:40?AM UTC-5, John Larkin wrote:
On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:

Kapton tape has much better dielectric strength and it comes with adhesive as well!
John

My son caught my mistake with a 4 output voltage divider using 4kV and 8kV. I was thinking,
1kV, 2kV, 3kv, and 4kv, and second test at 8kV output 5kV, 6kV, 7kV and 8kV.,
But the second test is 2kV, 4kV, 6kV and 8kV, not what we want.
So he wants 8 outputs, 1kV thru 8kV in 1kV steps.
He wants to use banana plugs for quick change.
Can we get away with this?
https://www.dropbox.com/s/dcjs0aon4zgxplw/Oil%20Water%208%20output%20Voltage%20Divider%20with%20Banana%20Connectors.jpg?dl=0
Would it help to cover the Resistor divider with a few layers of Kaptan tape?
Thanks, Mikek
Put a row of banana jacks on a piece of plastic. Solder the resistors
between the jacks the obvious way. Ordinary banana leads can run out
to the cells. Ignore corona. It\'s only an experiment and it\'s only
8KV.

Amazon has great banana jack assortments.

https://www.amazon.com/gp/product/B07KCRMV4V/

https://www.amazon.com/gp/product/B01CJDGWRU

These are cool on PC boards too.

John, I\'ll take that under advisement, however,
there could come a point in experiments, that I add a second transformer
and go up to 18kV or even 30kV. When we go to a larger diameter vessel,
the electric field per cm goes down, to compensate our input voltage needs to go up.
I\'m now hopefully going to start spending someone else\'s money on parts, so I have less concern.
I\'d like to build for possible future developments.
What about kaptan tape over the Resistive divider, does that help prevent corona?
Mikek

P.S. adding in my ignorance about HV projects, I\'d rather err on the side of gross overkill!


If you do simple stuff fast, you\'ll learn more.

too expensive, too late, or .. good enough

Our business is a struggle against the seductive force of complexity.

 

[Lamont Cranston]

On Sunday, May 14, 2023 at 9:07:04 AM UTC-5, Lasse Langwadt Christensen wrote:

søndag den 14. maj 2023 kl. 16.04.00 UTC+2 skrev John Larkin:

If you do simple stuff fast, you\'ll learn more.
too expensive, too late, or .. good enough

Arrgh !
Mikek

 

[Anthony William Sloman]

On Monday, May 15, 2023 at 12:04:00 AM UTC+10, John Larkin wrote:

On Sun, 14 May 2023 06:27:38 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 8:15:40?AM UTC-5, John Larkin wrote:
On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:

<snip>

> If you do simple stuff fast, you\'ll learn more.

But will you learn enough? Simple stuff is a way of getting started, but to stay competitive your products have do more than the competition, or become cheaper, and you need the best product, which isn\'t necessarily the simplest.

In this thread John has been touting the high-voltage valve/tube which isn\'t all that simple to use, though it may look that way to him.

--
Bill Sloman, Sydney

 

[Lamont Cranston]

On Sunday, May 14, 2023 at 9:20:31 AM UTC-5, Anthony William Sloman wrote:

On Monday, May 15, 2023 at 12:04:00 AM UTC+10, John Larkin wrote:
On Sun, 14 May 2023 06:27:38 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 8:15:40?AM UTC-5, John Larkin wrote:
On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:
snip
If you do simple stuff fast, you\'ll learn more.
But will you learn enough? Simple stuff is a way of getting started, but to stay competitive your products have do more than the competition, or become cheaper, and you need the best product, which isn\'t necessarily the simplest.

In this thread John has been touting the high-voltage valve/tube which isn\'t all that simple to use, though it may look that way to him.

--
Bill Sloman, Sydney

Bill, I want your input, because I\'ll soon start putting the high-voltage valve/tube pulser together, I\'d rather get it right the first time.

Also, on the oil/water emulsion,
Do you have a thought about about the relationship between the field strength used and the rate of separation?
Is it linear with drive voltage?
Is there a voltage where we would get diminishing returns?
Also, I got the idea from the literature that it is the water that is polar, not oils, so we are only moving water bubbles,
and bigger bubbles move farther under the electric field, colliding with smaller bubbles that move less. Does that sound right?
Thanks, Mikek

P.S So far we have found some of the feedstock is harder to separate then others using an electric field.

 

[piglet]

On 13/05/2023 4:13 pm, Lamont Cranston wrote:

That should have said I need to source a HV 1pf capacitor.
Mikek

Needn\'t be a single 10kV 1pF cap - you could have ten 1kV rated 10pF in
series or five 2kV 5pF etc etc

piglet

 

[Anthony William Sloman]

On Monday, May 15, 2023 at 12:35:12 AM UTC+10, Lamont Cranston wrote:

On Sunday, May 14, 2023 at 9:20:31 AM UTC-5, Anthony William Sloman wrote:
On Monday, May 15, 2023 at 12:04:00 AM UTC+10, John Larkin wrote:
On Sun, 14 May 2023 06:27:38 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 8:15:40?AM UTC-5, John Larkin wrote:
On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:
snip
If you do simple stuff fast, you\'ll learn more.

But will you learn enough? Simple stuff is a way of getting started, but to stay competitive your products have do more than the competition, or become cheaper, and you need the best product, which isn\'t necessarily the simplest.

In this thread John has been touting the high-voltage valve/tube which isn\'t all that simple to use, though it may look that way to him.

Bill, I want your input, because I\'ll soon start putting the high-voltage valve/tube pulser together, I\'d rather get it right the first time.

You won\'t. With luck you may learn enough to get something together that will work, but that\'s as much as I\'d hope for.

Also, on the oil/water emulsion.

Do you have a thought about about the relationship between the field strength used and the rate of separation?

If the droplets are really are small enough to form an emulsion the charge on each droplet should pretty uniform,and the rate of separation should be more or less linear with field. You probably won\'t get any kind of space charge in the emulsion as the droplets move towards the electrode - the charge is split between the droplet and the surrounding fluid and that averages out.

> Is it linear with drive voltage?

Probably.

> Is there a voltage where we would get diminishing returns?

When some other sort of conduction mechanism sets in, but that would probably end up as some kind of arc, so you\'d likely notice.

Also, I got the idea from the literature that it is the water that is polar, not oils, so we are only moving water bubbles,
and bigger bubbles move farther under the electric field, colliding with smaller bubbles that move less. Does that sound right?

Bigger droplets may distort into a more extended spindle/elliptical shape under the electric field, so you would expect them to move faster, but also to break up into smaller, more spherical bubbles

> P.S So far we have found some of the feedstock is harder to separate then others using an electric field.

Watch out for surfactants - soaps - in the feedstock. That changes the charged double layer around the droplet that creates the charge in the first place, and messes up the surface tension that makes the droplets sort of spherical, which will changes the way the droplets will distort while being dragged along by the electric field.

--
Bill Sloman, Sydney

 

[Lamont Cranston]

On Sunday, May 14, 2023 at 10:46:45 AM UTC-5, Anthony William Sloman wrote:

On Monday, May 15, 2023 at 12:35:12 AM UTC+10, Lamont Cranston wrote:
On Sunday, May 14, 2023 at 9:20:31 AM UTC-5, Anthony William Sloman wrote:
On Monday, May 15, 2023 at 12:04:00 AM UTC+10, John Larkin wrote:
On Sun, 14 May 2023 06:27:38 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 8:15:40?AM UTC-5, John Larkin wrote:
On Sun, 14 May 2023 05:30:59 -0700 (PDT), Lamont Cranston
amd...@gmail.com> wrote:
On Sunday, May 14, 2023 at 4:10:16?AM UTC-5, John Walliker wrote:
snip
If you do simple stuff fast, you\'ll learn more.

But will you learn enough? Simple stuff is a way of getting started, but to stay competitive your products have do more than the competition, or become cheaper, and you need the best product, which isn\'t necessarily the simplest.

In this thread John has been touting the high-voltage valve/tube which isn\'t all that simple to use, though it may look that way to him.

Bill, I want your input, because I\'ll soon start putting the high-voltage valve/tube pulser together, I\'d rather get it right the first time.
You won\'t. With luck you may learn enough to get something together that will work, but that\'s as much as I\'d hope for.

That\'s disheartening!
Maybe you could post a circuit you think would get the job done.

> Bigger droplets may distort into a more extended spindle/elliptical shape under the electric field, so you would expect them to move faster, but also to break up into smaller, more spherical bubbles.

There is data on small bubble chains forming (a detriment), but I will need to read again to find out why this happens.

P.S So far we have found some of the feedstock is harder to separate then others using an electric field.

Watch out for surfactants - soaps - in the feedstock. That changes the charged double layer around the droplet that creates the charge in the first place, and messes up the surface tension that makes the droplets sort of spherical, which will changes the way the droplets will distort while being dragged along by the electric field.

The stubborn oils have got better results with de-emulsifier added.
I\'ll need to look up how de-emulsiers work.

Mikek

 

[whit3rd]

On Sunday, May 14, 2023 at 6:27:43 AM UTC-7, Lamont Cranston wrote:

> What about kaptan tape over the Resistive divider, does that help prevent corona?

Not really; Kapton is a strong material, the tape is circa 0.001\" thick and
that\'s not adding much to the diameter. Large-diameter wires inhibits corona (if you have some
coax cable, use the shield because that has the large diameter). For a small apparatus,
it\'s probably not worth buying rated HV cable, just keep fingers and such
away from the HV parts. Any insulation OVER the coax shield is unlikely to hold off
HV for handling purposes; some experimenters use transparent PVC tube (Tygon)
when they need insulation; the vacuum-rated tube is thick-walled.

Putting bits of brass tubing over splice points is better than nothing.

If you smell ozone, something needs correcting.