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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Re: LTSpice Model for Photo Triac - VOM160
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: LTSpice Model for Photo Triac - VOM160
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
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. ?
22.11.2018, 22:29, "Eric Henares eohenares@... [LTspice]" <ltspice@...>:
?
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
?
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: Is there any problem of LTspice for macOS Mojave
Could you please check the FTT, I could not make it work. I'm using Mac with Mojave.
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Re: Have anyone built black hole model already ?
Hi, Andy:
Thank you. I don't mind to put an alert event in the schedule at the day which 130 days later than today, to remind me ask this again, if you could have the answer, 130 days is very worthful than this unreachable answer. :-)
Have a nice day ! ---In LTspice@..., <ai.egrps@...> wrote : Black hole?? I think you sent this about 130 days too early.
Andy
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Re: Have anyone built black hole model already ?
Black hole?? I think you sent this about 130 days too early.
Andy
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Re: Subcircuit in ASCII for HV9110
Evan,
I am pretty sure that nobody here has a SPICE model for the HV9110.? If someone did, they would have responded.
There is no need to ask this question repeatedly.? I think this is the fourth time you have asked it.
Just in case, I'll ask the obvious:? Did you contact the manufacturer already, to see if they have a SPICE model?? I did not find one on Microchip's website, but that doesn't exclude the possibility that they have one that isn't published on the web.? What did they say when you asked?
Andy
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Have anyone built black hole model already ?
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.
|
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
thanks!!
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Problem with FFT in LTspice Mac version
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.?
|
FFT in LTspice Mac version
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
Thank you for your help.?
|
Re: Trying to simulate a 27Mhz receiver. Couple of questions
The real question in my mind is what an antenna model would do in simulation.?
1. ?Do you want it to represent the actual terminal impedance of some real antenna? That, in itself, is challenging. EZNEC, referenced below, might help.
2. Do you want it to provide a signal to the receiver? If so, you can simulate that with a standard voltage (or current) source.
3. Do you want it to provide many signals over some band that you can ¡°tune in¡±? If this is what you want, there is a real problem ¡°tuning¡± the receiver during run time.?
4. Do you want many signals that you can use to test for ¡°adjacent channel¡± rejection? If so, you can simulate that with several standard voltage (or current) sources.
Jim, KA7EHK
James Wagner Oregon Research Electronics
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Re your antenna question --
Antennas can be very simple or very complex. But for example --
A simple center-fed half-wave dipole (about 17 feet long in your case)?
operated at its resonant frequency, and in free space or well away from?
everything else looks like a pure resistance of about 75 ohms. Incoming?
signals can be represented by a voltage source (modulated or otherwise)?
in series with this.
A quarter-wave whip antenna (around 8.5 feet long in your case) on an?
ideal ground plane acts like half a dipole, so ideally looks like a pure?
resistance of around 37 ohms.
These simple antennas have a useful bandwidth of a few percent; outside?
this range, they develop significant series reactance, and the?
resistance also changes.
Depending on your situation, these simple antennas may be practical. If?
you want to look further afield, EZNEC? () is? a good antenna?
analysis program -- it comes in demo and paid versions, with a good?
manual and examples.
As a general comment --
Making a small antenna is very easy.
Making a good antenna is easy (see above)
Making a good, small antenna can be very difficult.
Hope this is useful
Bob
---
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|
Re: Trying to simulate a 27Mhz receiver. Couple of questions
Re your antenna question --
Antennas can be very simple or very complex. But for example --
A simple center-fed half-wave dipole (about 17 feet long in your case) operated at its resonant frequency, and in free space or well away from everything else looks like a pure resistance of about 75 ohms. Incoming signals can be represented by a voltage source (modulated or otherwise) in series with this.
A quarter-wave whip antenna (around 8.5 feet long in your case) on an ideal ground plane acts like half a dipole, so ideally looks like a pure resistance of around 37 ohms.
These simple antennas have a useful bandwidth of a few percent; outside this range, they develop significant series reactance, and the resistance also changes.
Depending on your situation, these simple antennas may be practical. If you want to look further afield, EZNEC? (eznec.com) is? a good antenna analysis program -- it comes in demo and paid versions, with a good manual and examples.
As a general comment --
Making a small antenna is very easy.
Making a good antenna is easy (see above)
Making a good, small antenna can be very difficult.
Hope this is useful
Bob
---
This email has been checked for viruses by AVG.
|
Re: LTSpice Model for Photo Triac - VOM160
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
?
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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For fun add this line to compare between MODULATE and the formal equation:
a1 modulation 0 0 0 0 0 fm2 0 modulator mark={FC+DEVIATION} space={FC}
Compare node FM to FM2.? With 1nS max time step I get less than 100 microvolt difference between the two.? No doubt the MODULATE device is more accurate since it is no doubt implemented internally in source code (C or C++).
Dan
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Hello Dan,
The drawback of wave files is that the data values has to be between -1 and +1. That's why I prefer PWL-files. They have no such restrictions.
Best regards, Helmut
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Hello,
A V-source can read its PWL-data from a file.
Therefore place a V-source in the schematic. Then right-mouse-click on it and choose PWL-file.
LTspice will interpolate between the data points, if the FFT has to calculate data points between the defined data points.
If the simulation has finhshed, you can start the FFT.
Right-mouse-click into the waveform window -> View -> FFT.
Data format of the file: time value
I guess space(s), comma and tab(s) are possible seperation characters.
2 0
2.1 -1
2.2 0.5
2.3 0
2.4 -0.3
2.5 0.0
2.6 -0.1
2.7 0
2.8 0
Best regards, Helmut
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John Woodgate
Jan Didden