Re: Adjusting Bode plot phase
Jerry wrote:
? ? "The Bode plot of the input impedance shows a phase shift of 0 to -45 degrees, but the expected result is -45 to -90 degrees."
The impedance plot that I see goes from 0 to -90 degrees.
FYI, if you change V1 to AC 1V, it makes things easier.? Then the impedance equals the inverse of current.? Be careful about current directions, and voltage polarity.? If you plot the inverse of the current through V1, its current flows internally from?+ to -, which means it is externally from its - to?+ pins.? Note the arrow of the red current "probe" arrow in LTspice.
The impedance must start at 0 degrees at DC (very low frequencies).? It can't be constrained between -45 and -90 degrees, unless you mean over a limited frequency range.? Do you have a reference that says the impedance must be between -45 and -90 degrees?? Might that reference be wrong?? Or does it have qualifiers (such as, only between 10kHz and 1MHz)?
By the way, when uploading files, please upload only to the "Temp" folder.? (You didn't, but it's been fixed.)
? ??
To do that, FIRST navigate to that folder, and only THEN click the Upload button.
Regards, Andy
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Re: Adjusting Bode plot phase
Helmut,
I am plotting V(N002)/I(R11).? The plot profile looks OK, but, as mentioned, the phase is off by ~45 deg.
Thanks and best regards,
Jerry
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Re: Adjusting Bode plot phase
Hello Jerry,
I have opened your uploaded circuit, but I don't know which voltage or current I should look. I am very interested to see the paper where this circuit comes from. Please show a link and its name if possible.
Best regards, Helmut
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Re: Adjusting Bode plot phase
Helmut,
I uploaded the .asc file.? 20181123_exact_Paper_LTspice.
Thanks for all that you do!
Best regards,
Jerry
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Re: Rectifier with thyristor
Hello,
Your circuit requires 3 important changes.
The three V-source used as gate driver has to be connected to "Vout" instead of GND.
The series resistors of these V-sources has to be chnaged to e. g. 1kOhm to get reasonable gate currents.
The SCR has to withstand 560V in reverse direction. This means you should use a SCR with 800V breakdown voltage. I simply modified the model. I used Vdrm=800V Vrrm=800V. The SCR MCR706A can not be used for? this application, because it has only 400V breakdown voltage.
I have uploaded an example with all these changes.
3phase_rectifier.zip in the Temp-folder
Best regards, Helmut
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Re: Rectifier with thyristor
John noted, "Andy, I don't think a max time step was set, only a delayed start to saving data."
Oo, right.? My dyslexia (don't we all have a little, at times?) read it as ".tran 500m 0 20m".
Nevermind that part.
Andy
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Re: Rectifier with thyristor
I agree; the simulation runs OK. But you would
see much better if you gave the DC outputs different labels,
Vout1, Vout2,? Vout 3 and simulated from zero time to 50 ms. You
can then change the labels to connect all the DC outputs
together, or just keep one label and add a wire to connect them.
Andy, I don't think a max time step was set,
only a delayed start to saving data.
Best wishes
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates
Rayleigh, Essex UK
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csizikem,
please don't use those long URLs that begin with "".?
They are temporary, and might work only for you.?
Instead, just let us know that the file is named
"3ph_rectifier.rar" and that it is in the Temp folder.
Please
don't use .rar for files!? Please re-read the
instructions, and use .zip.
You
wrote, "...?the
the simulation don't work. Any idea?"
I
tried it, and it works.? I didn't see any smoke.? I
didn't see any error messages.? LTspice's simulation
ran.
So
please, tell us why you think it didn't work?
I will
say that it makes no sense to use a Maximum Timestep
of 20 milliseconds, with signals that have 1
microsecond risetimes.? Maximum Timestep should be
chosen so that it is faster than your fastest signal
events.
It
looks odd that you have applied the gate signals
relative to ground, yet the cathode of the SCR is far
from ground.? That doesn't look right.? Also, you
shorted the three phases together.? They are all named
"vout".? Was that intentional?
Regards,
Andy
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Re: Rectifier with thyristor
csizikem, please don't use those long URLs that begin with "".? They are temporary, and might work only for you.? Instead, just let us know that the file is named "3ph_rectifier.rar" and that it is in the Temp folder.
Please don't use .rar for files!? Please re-read the instructions, and use .zip.
You wrote, "...?the the simulation don't work. Any idea?"
I tried it, and it works.? I didn't see any smoke.? I didn't see any error messages.? LTspice's simulation ran.
So please, tell us why you think it didn't work?
I will say that it makes no sense to use a Maximum Timestep of 20 milliseconds, with signals that have 1 microsecond risetimes.? Maximum Timestep should be chosen so that it is faster than your fastest signal events.
It looks odd that you have applied the gate signals relative to ground, yet the cathode of the SCR is far from ground.? That doesn't look right.? Also, you shorted the three phases together.? They are all named "vout".? Was that intentional?
Regards, Andy
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Re: Rectifier with thyristor
The long link you give doesn't work. The never
do, they are only valid for a few minutes and usually only for
the uploader.
Best wishes
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates
Rayleigh, Essex UK
On 2018-11-23 16:41, John Woodgate
jmw@... [LTspice] wrote:
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?
No-one can tell by extra-sensory
perception. Upload your .ASC files AND all the other
files required to run the simulation as a ZIP archive to
Files => Temp and then tell us you did that.
Best wishes
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates
Rayleigh, Essex UK
?
Dear All!
I made a rectifier with thyristor (3ph). If I
simulated just one phase, then all right. If I
simulated the 3 phase, the the simulation don't work.
Any idea?
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Re: Adjusting Bode plot phase
No-one can tell by extra-sensory perception.
Upload your .ASC files AND all the other files required to run
the simulation as a ZIP archive to Files => Temp and then
tell us you did that.
Besides, LTspice is almost certainly giving
the right result for what you actually simulated, as opposed to
what you think you did.
Best wishes
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates
Rayleigh, Essex UK
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Group,
I have a circuit consisting of a 12-unit,
non-uniform RC ladder.? The Bode plot of the input
impedance shows a phase shift of 0 to -45 degrees, but
the expected result is -45 to -90 degrees.? Is there
some way to change spice parameters to get the results
to match?
Thanks in advance!
Jerry
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Re: Rectifier with thyristor
No-one can tell by extra-sensory perception.
Upload your .ASC files AND all the other files required to run
the simulation as a ZIP archive to Files => Temp and then
tell us you did that.
Best wishes
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates
Rayleigh, Essex UK
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Show quoted text
?
Dear All!
I made a rectifier with thyristor (3ph). If I simulated
just one phase, then all right. If I simulated the 3
phase, the the simulation don't work. Any idea?
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Re: Adjusting Bode plot phase
Hello Jerry,
Maybe you have you started at a too high frequency with your .AC simulation.
Have you really plottted V(out)? I ask because some users wrongly plot V(out)-V(in) instead of V(out)/V(in) or V(out).
You could upload your schematic(.asc)? file to our Files-section for a check if it's not confidental.
Best regards, Helmut
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Adjusting Bode plot phase
Group,
I have a circuit consisting of a 12-unit, non-uniform RC ladder.? The Bode plot of the input impedance shows a phase shift of 0 to -45 degrees, but the expected result is -45 to -90 degrees.? Is there some way to change spice parameters to get the results to match?
Thanks in advance!
Jerry
|
Dear All!
I made a rectifier with thyristor (3ph). If I simulated just one phase, then all right. If I simulated the 3 phase, the the simulation don't work. Any idea?
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Re: FFT in LTspice Mac version
Thank you, Helmut. I see. I will try to report it. Thanks again.
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Re: Problem with FFT in LTspice Mac version
Yes, the file is there, but it cannot be opened. I just simulated a sine wave to check it!!
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Re: FFT in LTspice Mac version
Hello,
I agree. The FFT-file created by MAC-LTspice has been corrupt. The problem is with the latest version of MAC-LTspice independent of the MAC-OS version. I tested the FFT with the jigs-example "27C.asc" with Mojave and High Sierra.
Please report this problem to the email address LTspice@...
Best regards, Helmut
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Re: Have anyone built black hole model already ?
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
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?
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: Problem with FFT in LTspice Mac version
Toahmadss wrote:
I'm having problem with FFT in LTspice Mac version. When I try to view FFT from the graph window, I get the following message:
Trouble opening file /Users/.../Documents/LTspice/Draft1.fft
Did you check whether the file is actually there? If not, there might be an issue with your simulation, what was the simulation command that you used for this run?
Jan
?
Hi,
I'm having problem with FFT in LTspice Mac version. When I try to view FFT from the graph window, I get the following message:
Trouble opening file /Users/.../Documents/LTspice/Draft1.fft
Thanks for your help.?
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John Woodgate
Jan Didden