Saving and restoring inductor current
LTspice can save and restore node voltages, but not branch currents.? This means that by using ".savebias time=<tstop>" and ".loadbias" a simulation with inductors is only partially saved and restored because inductor currents are ignored.? It occurred to me that by making a "dual inductor" using current sources and a capacitor, one might trick LTspice into saving "inductor" currents.? The inductor dual is very simple and can be a subcircuit with the inductor symbol edited to represent the dual inductor with the expected symbol.
.subckt L 1 2
.param L=1 Rser=1m Rpar=1/Gmin
C1 3 0 {L} Rser={1/Rpar} Rpar={1/Rser}
G1 1 2 3 0 1
G2 3 0 2 1 1
.ends L
This seems to work well and each run picks up where the previous run left off.? Here is a test simulation.
V1 1 0 1 AC 1
X1 1 2 L L=1m
C2 2 0 1
R1 2 0 1k
.tran 0 50 1u uic
.savebias bias.txt time=49.9
.loadbias bias.txt
Don't how this compares speed-wise and coupled inductors would require an extension, but this technique might prove useful in certain stepped simulations that could run much quicker if the operating point did not need to be refound each time.
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Re: Using BV exp(), log() for numerical compression ,wrong result ?
Hi, Andy:
Before your explanation, I didn't notice "complex logarithm" is a special case, maybe not supposed to be supported by any SPICE.
About the compression application, I didn't really have the complete idea, maybe it would be like the,.... For example, when someone reading a book, the edge on every page often empty, and be used to sketch some thing on, some graphs/pictures to decorate the layout of the page. They often are not the primary parts.
To analogy, if there are some main data, which typically are numerical values, and has its general scale on the range of greater than 0.01, though its format could support to very least 1e^-16, or some, such that, maybe I could merge those loged numbers secretly into the "main data", and leak .... to somewhere who concern it, without interference others who typically don't care those smaller values which is under 0.01.
Just some ignorant ideas. I didn't implement it yet.
Best regards. ---In LTspice@..., <ai.egrps@...> wrote : ericsson.sunshine wrote:
? ? "LTspice couldn't treat the negative value of nature log very well, which normally return the complex value ..."
? ? "LTspice couldn't see the complex (imaginary) parts. And treat it very well, as it should be treated in the normal math world."
I think most people here understand this: "The natural logarithm function ln(x) is defined only for x>0.? So the natural logarithm of a negative number is undefined."? Undefined means it has no defined value when x is negative, or zero.? I think in math, this would be represented by NaN (but I might be wrong).
The "complex logarithm" is an extension to complex numbers, but it differs from an ordinary logarithm.? Perhaps you work in a math world that treats the complex logarithm as a normal logarithm function, but I think most of us engineers do not.? The logarithm functions in LTspice are not defined to be complex logarithms, therefore one should not expect them to behave as complex logarithms; they are the ordinary variety of logarithm functions, which are undefined for negative arguments.? The exponential function exp() is not the inverse of the complex logarithm function.
Maybe it would help to understand what you are trying to accomplish.? I understand that you may be interested in compressing a wide dynamic range into a smaller one; but is this for signal processing?? Waveform visualization?? Theoretical analysis of non-physical signals or entities?? (Not that I'm asking for my own sake.? But it helps to know where one is going, before making the first steps, and finding that one has stepped into a hole.)
Regards, Andy
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Hey guys I¡¯m totally new to LTspice. I¡¯m using it to build guitar tube amps. One thing I need is to add a potentiometer. I tried following the help text file but could not get the potentiometer to actually work. I amable to use the symbol but that is as far as I¡¯ve gotten. I don¡¯t know how to install the .lib file to get it to work. I¡¯m sure this is very easy for everyone here but not for me as I am completely new to the program. If someone could provide a step by step instruction on how exactly to go about adding a potentiometer to LTspice I would greatly appreciate it. Thanks!
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Hey guys I'm totally new to LTspice. I'm using it to build guitar tube amps. One thing I need is to add a potentiometer. I tried following the help text file but could not get the potentiometer to actually work. I am able to use the symbol but that is as far as I've gotten. I'm sure this is very easy for everyone here but not for me as I am completely new to this program. If someone could provide a step by step instruction on how exactly to go about adding a potentiometer to LTspice I would greatly appreciate it. Thanks!
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Hey guys, I'm totally new to LTspice. I'm using it for building guitar tube amps. I really need to add a potentiometer to LTspice. I'm sure it is probably simple to everyone here but not to me. I read the help text file and I'm not able to get the potentiometer to actually work. If someone can please help with this I would greatly appreciate it. I would like a step by step guide on how exactly I go about adding a potentiometer. As far as I could get is being able to use the symbol. But I can't figure out how to add the .lib file and have the potentiometer actually work. Again, if I could get a step by step explanation on how exactly to add a working potentiometer that would be awesome. Sorry if I sound like such a newbie, because I am. thanks!
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Re: LTspice model for capacitor start single phase motor
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From: LTspice@... [mailto:LTspice@...]
Sent: Thursday, November 22, 2018 6:17 PM
To: LTspice@...
Subject: [LTspice] Re: LTspice model for capacitor start single phase motor? ? just trying to study how to proper run/ start a single phase motor with a inverter, I already have the inverter model , but seems have problem with the motor model with speed/torque. I can find a two phase motor and three phase examples. but nut sure how to build a single phase one. any example of single phase motor would be very helpful
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Re: Dark lines on light screens was : LTSpice Model for Photo Triac - VOM160
Jim wrote:
"My assumption of the reason I like it, is that the increased overall light level, causes the pupil to shrink, giving you better visual acuity & focus. YMMV"
Yup, makes sense.
It used to be that all computer CRTs were green or white on black. In my workplace I was one of few (early adopters?) who inverted the colors to make it look more like a printed page.
Andy
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Dark lines on light screens was : LTSpice Model for Photo Triac - VOM160
¡°What I do even differently from you, is to use a white (or
very light grey) background. I'm not the only one doing that. I am not
sure why I like dark waveforms on a light background, because oscilloscopes
didn't do that; but I find it more pleasing to my eye.¡±
My assumption of the reason I like it, is that the increased overall light level, causes the pupil to shrink, giving you better visual acuity & focus. YMMV
More of an issue for me with cad files, yellow on black?? Why ???????.? Give me dark blue on white, or light grey any day.
?
?
R James (Jim) Klessig P.E. | Senior Power Systems Engineer |
Electrical Reliability Services, VERTIV
jim.klessig@..., jim_klessig@...
1876 Gwin Rd, Mckinleyville | CA | 95519 | USA
| Cell (707) 497-9611 | eFax 614-410-0653
?
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by law. If you received this e-mail in error, any review, use, dissemination, distribution, or copying of the e-mail is strictly prohibited. Please notify the sender immediately by return e-mail and delete all copies from your system.
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Re: Using BV exp(), log() for numerical compression ,wrong result ?
ericsson.sunshine wrote:
? ? "LTspice couldn't treat the negative value of nature log very well, which normally return the complex value ..."
? ? "LTspice couldn't see the complex (imaginary) parts. And treat it very well, as it should be treated in the normal math world."
I think most people here understand this: "The natural logarithm function ln(x) is defined only for x>0.? So the natural logarithm of a negative number is undefined."? Undefined means it has no defined value when x is negative, or zero.? I think in math, this would be represented by NaN (but I might be wrong).
The "complex logarithm" is an extension to complex numbers, but it differs from an ordinary logarithm.? Perhaps you work in a math world that treats the complex logarithm as a normal logarithm function, but I think most of us engineers do not.? The logarithm functions in LTspice are not defined to be complex logarithms, therefore one should not expect them to behave as complex logarithms; they are the ordinary variety of logarithm functions, which are undefined for negative arguments.? The exponential function exp() is not the inverse of the complex logarithm function.
Maybe it would help to understand what you are trying to accomplish.? I understand that you may be interested in compressing a wide dynamic range into a smaller one; but is this for signal processing?? Waveform visualization?? Theoretical analysis of non-physical signals or entities?? (Not that I'm asking for my own sake.? But it helps to know where one is going, before making the first steps, and finding that one has stepped into a hole.)
Regards, Andy
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Re: CD4060 and CD4063 LTSpice models needed
Hi Eric, problem solved with CD4060, thanks.
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Re: CD4060 and CD4063 LTSpice models needed
Hi Andy, right now I found the CD4060 model in ToC, thanks.
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Re: Using BV exp(), log() for numerical compression ,wrong result ?
Hello,
Even log(0) is a big problem. The result be -infinity which is useless in a real circuit. That's why my suggested IF() has used a limit of 1e-6.
Best regards, Helmut
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Re: Using BV exp(), log() for numerical compression ,wrong result ?
Hi, Helmut:
Thank you for the suggestions, but if I use the IF() as you mentioned, x couldn't be recovered as it was before compression. But your answer seems LTspice couldn't treat the negative value of nature log very well, which normally return the complex value, eg: log(-2) =?0.6931 +? 3.1416i. As I said, LTspice couldn't see the complex (imaginary) parts. And treat it very well, as it should be treated in the normal math world.
Though I found another solution, it's using the dc-bias in the source signal, after recovered it, eliminate the dc-bias, this could be done well, too. But I am thinking, why LTspice couldn't treat those math functions equal-footing, alternatively, some math functions are biased, while some are? "NOT SUPPORTED/PARTLY SUPPORTED". Is it fair , unfair ?
Best regards, ---In LTspice@..., <helmutsennewald@...> wrote : Hello,
You have used log() from negative numbers. Normal calculators will fail in this case.
I recommend to use an IF() to workaround.
V=IF(V(x)<1e-6,0,log(V(x))
Be aware that log() is the same as ln(). log10() is the logarithm base 10.
Best regards, Helmut
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Re: CD4060 and CD4063 LTSpice models needed
4063 is a 4-bit magnitude comparator (for
comparing the dimensions of 1 dollar bills?), so is a purely
digital device and not very suitable for Spice simulation at
all.
Best wishes
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates
Rayleigh, Essex UK
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Show quoted text
?
electronicafrind
(Juan Esteban) wrote, "I need
CD4060 and CD4063 LTSpice models, .subckt and .asy
files."
When you
joined this group, you read about the "Table of
Contents" file (all_files.htm), which led you to the
CD4060 model and symbol.? How did that work out for you?
Sorry, I
can't help you with the CD4063.
Regards,
Andy
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Re: Have anyone built black hole model already ?
Hello, ES.
It's not easy to interpret your musings on
space-time, but in your first paragraph you actually ask for two
different, but related, things. There are many textbooks on
semiconductor theory and design, but don't expect them to
include the application of the theory to the design of Spice
models. You might be lucky to find a book that does that,
however. There are also textbooks and papers on the design of
Spice models, but they start from a prior understanding of the
concepts and relationships of semiconductor theory.
I can't give you references to actual
publications, but I'm sure there are others here who can.
'CMOS circuit design and simulation' is, I
think, about designing ICs, i.e. processes to make CMOS devices,
device dimensions required for a given performance, interactions
between nearby devices and many other things, This is neither
the basic theory that you want or the link from basic theory to
model design; it's more a 'workshop manual'.
Best wishes
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates
Rayleigh, Essex UK
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Show quoted text
?
Hello, John:
Thank you for the replies. Though several days ago, I
would like someone could suggest some materials (textbook)
about the semiconductors, electron-hole pairs, carriers,
etc. Everything needed for a SPCE modeling. I even don't
have the concept of where to begin. (Though I have heard
"CMOS circuit design layout and simulation", but I am not
sure if that's enough. And haven't done reading it yet.)
Though same "hole" things in this thread, but size is
completely different. I have less things to say about
black hole and the space things, I agree what you have
said about the 1-dimension or 3-dimension, that's what I
am familiar about, too. The idea is just an illusion. As
you said , no one could prove it. Especially this/(those)
body(ies) none exist in space (has no dimensions/size). No
bodies...so that, I just think if the time-space is
exchanged, time could be traveled, and space couldn't be
traveled, but still in it, how to explain ? does that
mean, fully filled the space , feel the all space ? Have
(in) it all, but couldn't travel move forward/backward.
Just some interesting thoughts, has anyone ever dreamed
about "being a small fish pursuit by a bigger one, and
felt the bloody mouth of the hunter", thus feel the
feeling/thoughts of the instances ?
Actually, this shouldn't be discussed here, so that, in
fact, what I really hope to learn is , more inspirations
about SPICE modeling.
If you could kindly help more inspirations.
Thank you very much.
Best regards.
---In LTspice@..., wrote :
Yes, there are many models of
black holes, but
none, I suppose, that are compatible with LTspice!
No existing
models are considered satisfactory. More research
is, of course,
needed.
There is a good explanation of
the distorting
effects of black hole gravity on space-time in
'From Eternity to
Here' by Sean Carroll, ISBN9781-85168-795-4.
If the Universe is a black hole
(as has indeed
been suggested), we would almost certainly not be
able to prove
it, because we are inside it. Your question about
'outside it'
is meaningless in terms of what we can know, and
may be
absolutely meaningless, by which I mean that if
there are other
black hole Universes, that might observe ours,
no-one there
could tell what is happening inside our Universe.
Opinion is divided on whether
other Universes
exist, and whether they could have different Laws
of Physics,
such as you suggest, where time-travel is easy and
three-dimensional, but space is one-dimensional
and space travel
is not easy. Note that physical bodies cannot
exist in a
Universe with fewer than two space dimensions, and
living bodies
as we know them require three dimensions.
Best wishes
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates
Rayleigh, Essex UK
?
Hi, :
I am curious about the black hole, so
though it's
almost impossible, but ...maybe someone
who might have
studied that before...that's did anyone
study hard about
the black hole very well and? have built
black hole
model already ?
Recently, I heard that, there is
theoretically
sayings which states "in the black hole,
the time-space
is exchanged,? which says in the black
hole, the
moving-direction is only one way
direction, and the time
for the one inside the black hole is very
slow (from
viewpoint of the outside one from black
hole), it seems
meaning, in the black hole, space is only
one way
direction while the time could be varying
forward
,backward, rightward, leftward,
etc.(time-space
exchanged)" , so that this saying caused
me the question
, is that possible that we are all living
in a bigggggg
BLACK HOLE, which includes the whole
universe, and in
this bigggggg BLACK HOLE, the time is one
way direction,
the space is traveling-abled,? as we
experienced so far,
but if this theory states is correct,
would that means
outside this bigggggg BLACK HOLE, OUT
THERE, time is
traveling-abled, and space is .....one way
direction-
LINED UP ? I don't quite know what's that,
so that's why
I'm here and the request, I hope to know
more about the
black hole , have anyone already built one
?
Thank you very much
Best regards.
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Re: Using BV exp(), log() for numerical compression ,wrong result ?
Hello,
You have used log() from negative numbers. Normal calculators will fail in this case.
I recommend to use an IF() to workaround.
V=IF(V(x)<1e-6,0,log(V(x))
Be aware that log() is the same as ln(). log10() is the logarithm base 10.
Best regards, Helmut
|
Re: Using BV exp(), log() for numerical compression ,wrong result ?
You know, if my window could tolerate a swing of 100, this method will help avoiding ruin my window. Since the swing could minimize from 1Mega to thirteen degree. Wouldn't you like to know the answer, possible or impossible ?
Or still the old problem, LTspice could see the complex (imaginary) part. Which does exist in the real world.
Best regards. ---In LTspice@..., <ericsson.sunshine@...> wrote : Hi, :
Please help, do you know how much powerful this will help, it could minimize the numerical value from 120dB to number '13.8155'. Which help to plot/sketch them in a single graph. Where stores much info and without distort it.
thank you very much. ---In LTspice@..., <ericsson.sunshine@...> wrote : Hi, :
While I am thinking using a mathematical compression (limit the numerical values to a scaled range, then revert them) algorithm, I found that in the BV device, the exp(), log() (natural algorithm) couldn't work as expect, normally I wish to use the math equation, x = log ( exp(x) ) or x = exp( log(x) ), but the waveform output disappointed me, the result from BV makes the 'x ' won't be the source of the signal.
Does anyone know why ? Can it be fixed ? Do I need any bias in LTspice ? I pretty sure some tools didn't need bias.
I have uploaded a file '20181126_20181126_BV_exp_log_convert.zip' at the temp folder.
Thank you very much.
Best regards.
|
Re: Using BV exp(), log() for numerical compression ,wrong result ?
Hi, :
Please help, do you know how much powerful this will help, it could minimize the numerical value from 120dB to number '13.8155'. Which help to plot/sketch them in a single graph. Where stores much info and without distort it.
thank you very much. ---In LTspice@..., <ericsson.sunshine@...> wrote : Hi, :
While I am thinking using a mathematical compression (limit the numerical values to a scaled range, then revert them) algorithm, I found that in the BV device, the exp(), log() (natural algorithm) couldn't work as expect, normally I wish to use the math equation, x = log ( exp(x) ) or x = exp( log(x) ), but the waveform output disappointed me, the result from BV makes the 'x ' won't be the source of the signal.
Does anyone know why ? Can it be fixed ? Do I need any bias in LTspice ? I pretty sure some tools didn't need bias.
I have uploaded a file '20181126_20181126_BV_exp_log_convert.zip' at the temp folder.
Thank you very much.
Best regards.
|
Using BV exp(), log() for numerical compression ,wrong result ?
Hi, :
While I am thinking using a mathematical compression (limit the numerical values to a scaled range, then revert them) algorithm, I found that in the BV device, the exp(), log() (natural algorithm) couldn't work as expect, normally I wish to use the math equation, x = log ( exp(x) ) or x = exp( log(x) ), but the waveform output disappointed me, the result from BV makes the 'x ' won't be the source of the signal.
Does anyone know why ? Can it be fixed ? Do I need any bias in LTspice ? I pretty sure some tools didn't need bias.
I have uploaded a file '20181126_20181126_BV_exp_log_convert.zip' at the temp folder.
Thank you very much.
Best regards.
|
Re: CD4060 and CD4063 LTSpice models needed
Hi Juan, The CD4060 is there in the files. There are several locations. You need to unzip the file. In one of them you will see the symbol and the subckt with a test schematic. But the subckt is a .M00 file. I tried the trial schematic. It works. Best regards, Eric
?
electronicafrind (Juan Esteban) wrote, "I need CD4060 and CD4063 LTSpice models, .subckt and .asy files."
When you joined this group, you read about the "Table of Contents" file (all_files.htm), which led you to the CD4060 model and symbol.? How did that work out for you?
Sorry, I can't help you with the CD4063.
Regards, Andy
|
John Woodgate