Re: Loss simulation problem
Magic!
It's working!
Many thanks (K?sz?n?m!)! (:
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Le 12/07/2023 ¨¤ 16:45, Richard Andrews via groups.io a ¨¦crit?:
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
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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:
toggle quoted message
Show quoted text
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.
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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.
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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
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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
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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
?
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Re: Warning: Multiple definitions of model ...
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:
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Show quoted text
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
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Re: Warning: Multiple definitions of model ...
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:
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Show quoted text
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.
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Re: Loss simulation problem
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:
toggle quoted message
Show quoted text
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
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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 ...
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:
toggle quoted message
Show quoted text
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
|
Re: Warning: Multiple definitions of model ...
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.
Regards
Francesco
|
Re: Loss simulation problem
I'm always losing transistors, too. I have no idea why - maybe I'm
just forgetful. ?
I think you probably mean power dissipation.
If the thermometer doesn't appear, can you still plot currents of
the transistor? If you can't plot currents either, check that:
Control Panel > Save Defaults > Save
Device Currents
.. is checked.
If it is, perhaps you can upload a troublesome schematic where you
can't plot dissipation?
--
Regards,
Tony
On 12/07/2023 11:33, Csizmadia Mikl?s
wrote:
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Show quoted text
is it only me
who finds it strange (or does it not work )that the loss of
transistors cannot be simulated? I can't see the little
thermometer. Does this function not work for you either?
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Dear all,
?
is it only me who finds it strange (or does it not work )that the loss of transistors cannot be simulated? I can't see the little thermometer. Does this function not work for you either?
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Re: Filters (Butterworth, Chebychev etc.)
Thanks for uploading the file. As said, I got it meanwhile. And thanks for pointing out LTSPIC¡¯s builtin filter functions.
¡ª Christoph
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Show quoted text
Am 12.07.2023 um 10:36 schrieb Tony Casey < tony@...>:
I didn't have any trouble downloading Filt.zip - must be something
in your Firefox setup. Perhaps you are using the HTTPS Everywhere
add-in? You can disable the "https only" option, or temporarily
disable the add-in.
If you still can't download it, I have placed it in Files > Temp,
Filt.zip.
Don't forget, there are also 2nd order filter functions in the
LTspice pre-installed libraries:
Place Component (F2) > SpecialFunctions
--
Regards,
Tony
On 12/07/2023 09:08, Christoph wrote:
I
would like to apply filters to a signal of discrete sample points
and watch the effect of order, gain and other characteristics.
Found this page:
Firefox refuses to download the files (e.g. Filt.zip
at the bottom of the page) since the links aren¡¯t secured. Any
alternatives?
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Re: Filters (Butterworth, Chebychev etc.)
I didn't have any trouble downloading Filt.zip - must be something
in your Firefox setup. Perhaps you are using the HTTPS Everywhere
add-in? You can disable the "https only" option, or temporarily
disable the add-in.
If you still can't download it, I have placed it in Files > Temp,
Filt.zip.
Don't forget, there are also 2nd order filter functions in the
LTspice pre-installed libraries:
Place Component (F2) > SpecialFunctions
--
Regards,
Tony
On 12/07/2023 09:08, Christoph wrote:
toggle quoted message
Show quoted text
I
would like to apply filters to a signal of discrete sample points
and watch the effect of order, gain and other characteristics.
Found this page:
Firefox refuses to download the files (e.g. Filt.zip
at the bottom of the page) since the links aren¡¯t secured. Any
alternatives?
|
Re: Filters (Butterworth, Chebychev etc.)
Now got one of these filters into my circuit. Anyone familiar with these models?? How do I have to set the parameters for a low pass filter, of, say, corner freq. = 100Hz?
|
|---|
| ´Ü¾±²Ô=&±ô³Ù;-1,0,0+..¡Þ&²µ³Ù; |
¦¸ |
Input impedance. There are three possible settings:
- Zin=-1 ? zero-impedance input (voltage source)
- Zin=0 ? high-impedance input (current source)
- Zin>0 ? µ÷´Ü¾±²Ô°¨¦¸
|
| ´Ü´Ç³Ü³Ù=&±ô³Ù;0,0+..¡Þ&²µ³Ù; |
¦¸ |
Output impedance. There are two possible settings:
- Zout=0 ? high-impedance output (floating)
- Zout>0 ? µ÷´Ü´Ç³Ü³Ù°¨¦¸ output
|
| Only one of the impedances can be zero at a time! |
| fp1, fs1, fp2, fs2 |
Hz |
Corner frequencies for the passband and stopband, defaults <500,400,2k,2.5k> |
| BWp, BWs, fc |
Hz |
Alternate frequency settings: passband bandwidth,
stopband bandwidth, and center frequency, defaults are calculated based
on the corner frequencies and, based on those, <1.5k,2.1k,1k> |
| As |
dB |
Stopband attenuation, default 40 |
| Asc |
dB |
Frequency-scaling attenuation. If Asc=0, N>0 the passband is optimized. Default 3.0103 |
N=<0:1:32>
N=<0:2:64> |
- |
Order of the filter, its value represents the order
after the frequency transformations. For lowpass and highpass the
maximum order is 32 and can take odd and even values. For bandpass and bandstop it's 64, but only even values are valid. If N=0 and Asc>0, the minimum order is determined based on the values of the frequencies and attenuations. Default 13 |
| sim |
s |
Total .TRAN simulation time, default 1 |
|
| Rpar, Rser |
¦¸ |
LTspice's specific for inductors and capacitors, common for both (i.e. setting Rser means inductors and capacitors, together, will have it set, same for Rpar), defaults <1g,0> |
¡ª
toggle quoted message
Show quoted text
Am 12.07.2023 um 09:39 schrieb Christoph < kuku@...>:
Am 12.07.2023 um 09:08 schrieb Christoph < kuku@...>:
I would like to apply filters to a signal of discrete sample points and watch the effect of order, gain and other characteristics. Found this page:
Firefox refuses to download the files (e.g. Filt.zip at the bottom of the page) since the links aren¡¯t secured. Any alternatives?
OK, I managed to download the Filt.zip file using?
$?wget
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John Woodgate
Tim Hutcheson
Tony Casey
Christoph