Re: LTSpice Model for Photo Triac - VOM160
Hi Andy, What I mean is when a file name has the "2 input and gate" drawing before the file name, then what I know is it is a symbol file that can be loaded directly to the "sym" directory.? When a file name has the "NPN bjt transistor" drawing before the file name, then my understanding is it is a schematic file and can be saved under a LTspice schematics folder. When a file name has the " .lib " after the file name, then my understanding is it is the model simulation file and can be loaded directly into the "sub" directory.? Bordodynov's file name has ".asy" after it but no "and gate" or "npn" drawing icon before it so I'm not sure where to save that kind of file. But anyway I'm learning so much from all of you. Best regards, Eric
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Eric, I think Bordodynov's symbol uses the same technique as one of the two I described.
I'm not sure what you say about the AND gate, because none of these symbols had AND gate icons in them.? In any event, like any other symbol, it can live either in the same directory with the schematic that uses it, or in the Documents\LTspiceXVII\lib\sym directory tree.
Regards, Andy
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Re: Adjusting Bode plot phase
Hello Jerry,
I am very interested to see the paper. This helps me to check whether the implementation in LTspice is equivalent.
Best regards, Helmut
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Re: LTSpice Model for Photo Triac - VOM160
Eric, I think Bordodynov's symbol uses the same technique as one of the two I described.
I'm not sure what you say about the AND gate, because none of these symbols had AND gate icons in them.? In any event, like any other symbol, it can live either in the same directory with the schematic that uses it, or in the Documents\LTspiceXVII\lib\sym directory tree.
Regards, Andy
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Re: LTSpice Model for Photo Triac - VOM160
Hi Andy, Thank you so much once again. It already worked with the first approach in your earlier email so maybe I can try this one if a new oppurtunity comes. Best regards, Eric
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Eric, there is another way to have the symbol automatically load a library file.? That is to use the ModelFile attribute.? See the same Help page as in my previous reply, as well as this one: Schematic Capture > Editing Components > Super Expert Mode.? Near the bottom of that Help page it says that if the Prefix is "X" (it is) and if a ModelFile attribute is defined (you should set it to MOC308x.lib, if you want to use this option), then LTspice will automatically load that file as if you had written ".lib MOC308x.lib".? This attribute also must be added in LTspice's symbol editor, and again it would be best to delete the symbol from your schematic and re-add it after making the change to the symbol.
Because this library file MOC308x.lib contains three subcircuits, you will be able to select which subcircuit to use, after the symbol is added to your schematic, as it says at the very bottom of that Help page.? To do that:? Right-click on the symbol on the schematic.? Then click on the name after SpiceModel.? It should show you the three available subcircuits.
Regards, Andy
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Re: Adjusting Bode plot phase
Jerry wrote, "I am plotting V(N002)/I(R11)."
FYI, that does not constitute impedance.
Even though it has the right units, V(N002) is not across R11, therefore it is something other than impedance.
Again, think what happens when you remove all the capacitors -- which represents what happens at very low frequencies.? V and I would be in-phase, so the phase shift would be zero and can't be between -45 and -90.? If a paper suggests otherwise, either it's wrong, or being interpreted incorrectly.
Regards, Andy
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Re: LTSpice Model for Photo Triac - VOM160
Hi Andy, Thank you very much again! It works! Really appreciate your perseverance to help and support us newbies to LTspice XVII. Best regards, Eric
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Eric, see this Help page: Schematic Capture > Creating New Symbols > Adding Attributes.? Quoting from that page:
? ? "There is a special combination of attributes that will cause a required library to be automatically included in every schematic that uses the symbol."
It then shows you that combination.? Those attributes must be added to the symbol in LTspice's symbol editor -- not on the schematic page.? Then go to Edit > Attributes > Edit Attributes (or press ctrl-A) to change the attributes.? Once the symbol is saved with those attributes, you may need to delete and add the symbol again to your schematic, for the changes to take effect there.
The SpiceModel attribute should be the name of the file.? In your case, that would be MOC308x.lib.? I recommend no directory path.? That works both if the file is in the folder with the schematic, or if it is in LTspice's library area.
The Value2 attribute should be the name of the subcircuit, the thing that comes after .SUBCKT.? In your case, that would be MOC3083.
Regards, Andy
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Re: LTSpice Model for Photo Triac - VOM160
Hello Bordodynov, Thank you for your advise. I checked it out but was a bit confused how and where to save it as it doesn't have the "and gate" icon for a symbol. But? thank you very much for taking your time also to help.? I also saw the replies from Andy and thought it was easier to do for me. This community is simply full of very supportive and sincere participants. Best regards,
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Hi. An example of a symbol with an internal library reference. See MOC3083.asy in TEMP folder. In my collection of models, this particular symbol. ? Bordodynov. ?
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Hi Andy, Thanks again so much for your help.I was able to save the part with name MOC3083 already on it.?
But I wasn't able to do the automatic MOC308x.lib search. I tried the LTspice Help using "Model and Library Search Path" topic. I entered the directory path for the newly saved symbol MOC3083? and the directory path for MOC308x.lib and saved. But it didn't work or do anything. Still the schematic without the .lib MOC308x.lib directive wouldn't run. I also tried? the FAQ but can't find the right instruction there for the automatic directive search. But its ok already at this point. I can easily add the directive everytime I use the part.?
Incidentally I might have to ask help also on loading another part if I can't still do it. But it will be on New Topic:).
Thanks and best regards, Eric
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Eric asked, "How do I now permanently save the part that has already MOC3083 on it instead of? LED_TRIAC_ZCS, ..."
That's easy.? Edit the symbol and save it.? Open the symbol file in LTspice.? You can right-click on it when it's on your schematic, then click Open Symbol.? Then right-click on that text and change it.? It happens to be an Attribute of the symbol.? Then save the file.? If you want to, you could save it under a different filename, but then you'd probably want to edit your schematics too.
? ? "...?and what needs to be done?so I don't have to add the directive? ?..lib MOC308x.lib? everytime I use this part?"
There are ways to put the library filename into the symbol itself, but to be honest I don't remember them.? I think there is more than one way, but they come with side-effects which is one reason why I tend to avoid it.? If you read through the LTspice Help (remember that?) it lists at least one of them.? I think one of the consequences is that you can no longer open or edit the symbol from a schematic page.? Which might not be an issue for you.
Some of the symbol attributes work in unexpected ways..
Regards, Andy
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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
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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
toggle quoted message
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
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John Woodgate