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Re: Spark gap physics.

 

That's it I forgot the pressure even though it's in the equation.


Re: Spark gap physics.

 

The shape and the type of the electrode also change the arcing characteristics.?


Re: Spark gap physics.

 

Yes I am familiar with Paschen's Law just don't know it like the back of my hand.


Re: Spark gap physics.

 

It is also related to gas pressure. There are graphs on the wikipedia page for Paschens Law that show breakdown voltage versus gas pressure, but I cannot recall if it included gap length.

There is a pressure and distance for each gas where the breakdown voltage is lowest. Go below that pressure and the number of molecules in the spark gap drop to a point where you need a higher electric field to make it arc over, go higher in pressure and there are more atoms able to resist the electric field.


On Wed, 12 Jul 2023 at 15:53, Jerry Lee Marcel <jerryleemarcel@...> wrote:

Le 12/07/2023 à 16:45, Richard Andrews via a écrit?:
>
> As the gap widens, the voltage required to initiate a spark increases
> exponentially.

Are you sure of this? I had a notion that ionization appeared at a given
field strength, which is more or less a direct relationship of voltage
divided by gap length.

Check this







Re: Spark gap physics.

 

There is a very good wikipedia page on Paschens Law.


On Wed, 12 Jul 2023 at 15:52, John Woodgate <jmw@...> wrote:

OK so far, I think. Have you done a web search for 'Paschen's Law'?

======================================================================================
Best wishes John Woodgate OOO-Own Opinions Only

Rayleigh, Essex UK

I hear, and I forget. I see, and I remember. I do, and I understand. Xunzi (340 - 245 BC)


On 2023-07-12 15:45, Richard Andrews via wrote:
Trying to grasp the resistance in a spark gap I had to write what I know.
If anyone can refute my ideas, let me know.

The voltage and current relationship when a spark gap's gap is increased is as follows:

??? Voltage: The voltage required to initiate a spark across the gap increases
??? as the gap widens. This is because the air in the gap has to be ionized
??? before a spark can occur, and it takes more voltage to ionize the air as
??? the gap widens.

??? Current: The current that flows through the spark gap after it has initiated
??? is relatively constant, regardless of the gap width. This is because the
??? resistance of the ionized air is very low, so a large current can flow even
??? with a small voltage difference.

??? For example, spark gaps are used in spark-ignition engines to ignite the
fuel-air mixture. The spark plug in a spark-ignition engine has a gap of about
0.020 inches, and the voltage required to initiate a spark across this gap is
about 20,000 volts. However, once the spark has initiated, the current that
flows through the spark plug can be as high as 20 amperes.

??? The relationship between voltage and current in a spark gap is not linear.
As the gap widens, the voltage required to initiate a spark increases
exponentially. This means that a small increase in the gap width can result in
a large increase in the voltage required to initiate a spark.

??? The voltage and current relationship in a spark gap is also affected by the
type of gas that is present in the gap. Air is the most common gas used in
spark gaps, but other gases such as argon and helium can also be used.
The breakdown voltage of a gas is the voltage required to ionize the gas,
and it is different for different gases. This means that the voltage required
to initiate a spark in a spark gap will be different depending on the type of
gas that is present in the gap.


Re: Loss simulation problem

 

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Ne említse meg!

--
Regards,
Tony

On 12/07/2023 16:57, Csizmadia Mikl?s wrote:

Magic!
It's working!

Many thanks (K?sz?n?m!)! (:


Re: Loss simulation problem

 

Magic!
It's working!

Many thanks (K?sz?n?m!)! (:


Re: Spark gap physics.

 

Le 12/07/2023 à 16:45, Richard Andrews via groups.io a écrit?:

As the gap widens, the voltage required to initiate a spark increases
exponentially.
Are you sure of this? I had a notion that ionization appeared at a given field strength, which is more or less a direct relationship of voltage divided by gap length.

Check this


Re: Spark gap physics.

 

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OK so far, I think. Have you done a web search for 'Paschen's Law'?

======================================================================================
Best wishes John Woodgate OOO-Own Opinions Only

Rayleigh, Essex UK

I hear, and I forget. I see, and I remember. I do, and I understand. Xunzi (340 - 245 BC)


On 2023-07-12 15:45, Richard Andrews via groups.io wrote:

Trying to grasp the resistance in a spark gap I had to write what I know.
If anyone can refute my ideas, let me know.

The voltage and current relationship when a spark gap's gap is increased is as follows:

??? Voltage: The voltage required to initiate a spark across the gap increases
??? as the gap widens. This is because the air in the gap has to be ionized
??? before a spark can occur, and it takes more voltage to ionize the air as
??? the gap widens.

??? Current: The current that flows through the spark gap after it has initiated
??? is relatively constant, regardless of the gap width. This is because the
??? resistance of the ionized air is very low, so a large current can flow even
??? with a small voltage difference.

??? For example, spark gaps are used in spark-ignition engines to ignite the
fuel-air mixture. The spark plug in a spark-ignition engine has a gap of about
0.020 inches, and the voltage required to initiate a spark across this gap is
about 20,000 volts. However, once the spark has initiated, the current that
flows through the spark plug can be as high as 20 amperes.

??? The relationship between voltage and current in a spark gap is not linear.
As the gap widens, the voltage required to initiate a spark increases
exponentially. This means that a small increase in the gap width can result in
a large increase in the voltage required to initiate a spark.

??? The voltage and current relationship in a spark gap is also affected by the
type of gas that is present in the gap. Air is the most common gas used in
spark gaps, but other gases such as argon and helium can also be used.
The breakdown voltage of a gas is the voltage required to ionize the gas,
and it is different for different gases. This means that the voltage required
to initiate a spark in a spark gap will be different depending on the type of
gas that is present in the gap.


Spark gap physics.

 

Trying to grasp the resistance in a spark gap I had to write what I know.
If anyone can refute my ideas, let me know.

The voltage and current relationship when a spark gap's gap is increased is as follows:

??? Voltage: The voltage required to initiate a spark across the gap increases
??? as the gap widens. This is because the air in the gap has to be ionized
??? before a spark can occur, and it takes more voltage to ionize the air as
??? the gap widens.

??? Current: The current that flows through the spark gap after it has initiated
??? is relatively constant, regardless of the gap width. This is because the
??? resistance of the ionized air is very low, so a large current can flow even
??? with a small voltage difference.

??? For example, spark gaps are used in spark-ignition engines to ignite the
fuel-air mixture. The spark plug in a spark-ignition engine has a gap of about
0.020 inches, and the voltage required to initiate a spark across this gap is
about 20,000 volts. However, once the spark has initiated, the current that
flows through the spark plug can be as high as 20 amperes.

??? The relationship between voltage and current in a spark gap is not linear.
As the gap widens, the voltage required to initiate a spark increases
exponentially. This means that a small increase in the gap width can result in
a large increase in the voltage required to initiate a spark.

??? The voltage and current relationship in a spark gap is also affected by the
type of gas that is present in the gap. Air is the most common gas used in
spark gaps, but other gases such as argon and helium can also be used.
The breakdown voltage of a gas is the voltage required to ionize the gas,
and it is different for different gases. This means that the voltage required
to initiate a spark in a spark gap will be different depending on the type of
gas that is present in the gap.


Re: Warning: Multiple definitions of model ...

 

Tim wrote, "... The only way to observe the cat is to place the observer in the box and then the state of the system (its reality) is completely different because it is a different reality.? The observers quantum state is coupled with the cat in QFT."

But then the problem would be that if the poison is released, the observer dies too.? And then, since the observer did not observe the dead cat, is the cat still both dead and alive, until someone else opens the box?

What this has to do with reality (um, real reality?), I haven't a clue.? ;-)

Andy


Re: Filters (Butterworth, Chebychev etc.)

 

Tony wrote, "I didn't have any trouble downloading Filt.zip - must be something in your Firefox setup. ..."

I think the problem is that the LTwiki website uses http: (not secure https:) in many places.? That was a problem for the main LTwiki webpages too.? Currently, for me, the main LTwiki webpage (for information about LTspice) now uses https:, but the branches for Vlad's and Bordodynov's files still do not.? I don't use Firefox, but I guess Firefox (depending on its settings) might prevent you from downloading anything with an http: URL.? Google Chrome complains mightily, but if you are persistent and ignore all its warnings about it, you can get it to download from http: URLs.? Bit of a PITA.

Andy


Re: Warning: Multiple definitions of model ...

 

Sean Carrol tries to explain this here, at about 30 minutes in:????
Great bubblegum for the brain there.? I think he is saying position is a special limit that produces our classical interpretation of reality. Maybe reality is where the limit takes us into a linear region of the solution space, very much like the way LTspice linearizes our circuits to solve the differentials

Just keeping on topic here.? :-)

Tim

?


Re: Warning: Multiple definitions of model ...

 

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Perhaps this is why we sometimes refer to a "dead and alive place"? The doesn't mention quantum mechanics.

--
Regards,
Tony


On 12/07/2023 13:15, John Woodgate wrote:

Well, that is a sort of opposite to the cat. It's real, but so far inexplicable.

======================================================================================
Best wishes John Woodgate OOO-Own Opinions Only

Rayleigh, Essex UK

I hear, and I forget. I see, and I remember. I do, and I understand. Xunzi (340 - 245 BC)


On 2023-07-12 12:06, mhx@... wrote:
On Tue, Jul 11, 2023 at 07:43 PM, eewiz wrote:

And there lies "the (philosophical) flaw."

Nothing in this universe is instantaneous.
Analyses that assume any sort of instantaneousness are simply flawed to start  with.
[..]

Like quantum entanglement?

-marcel







Re: Warning: Multiple definitions of model ...

 

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I can't really comment on QSPICE as I haven't tried it. It's not clear how I can. I signed up for access to the beta test, but heard nothing more. I haven't joined the user group, either. But I'm not alone there - only 183 people have, so far. Nevertheless, good luck to them. Having competition is good.

As far as the need for speed is concerned: obviously it's not a bad thing, but people obsess too much about it. With crappy models that barely converge, the underlying speed of the simulator is irrelevant, anyway. I suspect people waste more time on fixing mistakes and not simulating the right thing than they can ever gain by using a faster PC or simulator.

Please - no more compliments. I must be hard enough to live with already. ? But, thanks.

--
Regards,
Tony


On 12/07/2023 12:27, Francesco wrote:

Tony, I'm with you almost 100%! The only questionable point may be QSPICE. I'm often conflicted between keeping LTspice as the only one, and invest time only there, or trying to spend some effort in checking QSPICE. I think it has some strength against LTspice, but honestly, do we really need it? I think someone like you should take part in the evaluation of this new tool, in case even to decide it does not make sense to shift on it. But I agree, if you feel good with LTspice (as I do), why should you move from it? Nevertheless, the higher speed and some other features of QSPICE are attracting. I think it is still in a preliminary phase, probably too early for one like you to invest time in it. Just thoughts.

My compliments for your wonderful English! I like reading your posts even for learning some language usage! Thanks for teaching.


Re: Loss simulation problem

 

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Yes, the apologies should be mine. It was clear that English probably wasn't your first language - I wouldn't attempt anything in Hungarian. But sometimes I can't resist.

Thanks for your upload, but please, next time use zip only, as per the instructions on the homepage. The reason we ask for zip is that every computer can access them? without installing and using additional utilities.

I tried your schematic, and I can plot the dissipation of both MOSFETs, Q1 and U1. Please check your settings against Save_Defaults. This is what I got: Waveforms.

--
Regards,
Tony


On 12/07/2023 12:55, Csizmadia Mikl?s wrote:

You are right. I apologize, I am writing from Hungary. My English is, um... But you get the point (:

Even if I put the cursor on the semiconductor, it doesn't turn into a thermometer.

I checked the setting, and it's okay.

The example file you can find here: /g/LTspice/files/Temp/3878_temp_test.rar


Re: Warning: Multiple definitions of model ...

 

You have to think about it the other way around.? One doesn't open the box and observe the cat.? The only way to observe the cat is to place the observer in the box and then the state of the system (its reality) is completely different because it is a different reality.? The observers quantum state is coupled with the cat in QFT.


Re: Warning: Multiple definitions of model ...

 

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Well, that is a sort of opposite to the cat. It's real, but so far inexplicable.

======================================================================================
Best wishes John Woodgate OOO-Own Opinions Only

Rayleigh, Essex UK

I hear, and I forget. I see, and I remember. I do, and I understand. Xunzi (340 - 245 BC)


On 2023-07-12 12:06, mhx@... wrote:

On Tue, Jul 11, 2023 at 07:43 PM, eewiz wrote:

And there lies "the (philosophical) flaw."

Nothing in this universe is instantaneous.
Analyses that assume any sort of instantaneousness are simply flawed to start  with.
[..]

Like quantum entanglement?

-marcel






Re: Warning: Multiple definitions of model ...

 

On Tue, Jul 11, 2023 at 07:43 PM, eewiz wrote:

And there lies "the (philosophical) flaw."

Nothing in this universe is instantaneous.
Analyses that assume any sort of instantaneousness are simply flawed to start with.
[..]

Like quantum entanglement?

-marcel


Re: Loss simulation problem

 

You are right. I apologize, I am writing from Hungary. My English is, um... But you get the point (:

Even if I put the cursor on the semiconductor, it doesn't turn into a thermometer.

I checked the setting, and it's okay.

The example file you can find here: /g/LTspice/files/Temp/3878_temp_test.rar