MosFet "LEVELS" in LTSpice compared to other spice simulators
Hello,
I am getting confusing hints from search results: .. So a mosfet "level" is a way to model a mosfet using a set of defined parameters. (?) There are many so called "levels" and there have been numbers assigned to them, without this meaning that one is necessarily an evolution of the previous. I see on this manual for example (http://ecee.colorado.edu/~mathys/ecen1400/pdf/scad3.pdf) that ltspice can understand at least 10 of these levels.
1)Is this numbering kept same across LTSpice, PSpice, HSpice? 2)Do all simulators use all the parameters with the same name or are they free to introduce/remove/mix parameters? 3)Will LTSpice complain if we pass to it a parameter name that it cannot understand in a model, or just ignore it without reporting?
4)Is there some solid documentation on ALL of the ltspice mosfet levels?
Any hints welcome, thanks!
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Hello,
You could use the command from the menu
Plot Settings -> Autorange Y-axis
The shortkey is Ctrl-y
Best regards,
Helmut
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(1) Choose any plot, drag a rectangle over it all, then all
plots get same time axis limits.
(2) Doing this with "Manual Limits" only zooms the plot selected
(not all).
So: What I'd like to be able to do is -
?? To precisely specify "Manual Time Limits" for all plots at
once - like (1) and (2) combined. --- I gather there is a way to do this, "lock horizontal axis" - but I have not found how to acess this feature yet.
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Re: Pull-Push transformer for valve amp in LTspice
Hello analogspiceman
I'm not denying that your library works (I have used it a few times, successfully) or that a quasi-real transformer can not be built around the Chan core, but I have never used it with two primaries, which is why I lacked the experience in how to do it and the only very vague notion I had was the remembrance of a past conversation that may have been related to a push-pull, which I couldn't find in the archives. It's also true I didn't insist in searching for it too much but, it's irrelevant now, the question has been answered. Besides, I did try a quick example and I convinced myself that I was wrong (see my post above), which probably means I'm also confused about the memory. And... that's pretty much it.
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Re: Pull-Push transformer for valve amp in LTspice
Hello Vlad, a transformer has multiple windings, but only one core (which is the only nonlinear part).? That is why LTspice does not allow coupling between saturating inductors (either Chan or behavioral).? If a Chan model is used, it must represent only the single common core, not one for each winding (as can be done for perfectly linear windings).? However, it is quite easy to construct a transformer model such that there is only a single internal core part and an arbitrary number of windings, including any number of identical parallel or push-pull primary windings.? A good and proper model matches reality, so it has no problem with any of these typical realistic hook ups.? The model I created does this very well.
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Re: Need triangular wave with using PWL mode
Hello See Triangular_Pulse_Wave.zip on
| | | | Yahoo! Groups offers free mailing lists, photo & file sharing, group calendars and more. Discuss hot topics, share interests, join online communities. | | | | Preview by Yahoo | | | ?Regards PhB
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Re: Need triangular wave with using PWL mode
Kevin replied:
? ? "? PULSE(-6 6 0 5m 5m 1p 10m)" That is how I'd do it too. ?Except that I probably would have used 0 rather than 1ps, because the on-time Ton is allowed to be zero. ?The waveform is indeed piecewise linear.
But if Mete insists on using an actual PWL source, you could?have?this: ? ?PWL (0ms -6v 5ms 6v 10ms -6v 15ms 6v 20ms -6v 25ms 6v 30ms -6v) but you need to keep adding points to last the full simulation. ?Or do this, using LTspice's undocumented "repeat forever" syntax:
? ?PWL REPEAT FOREVER (0ms -6v 5ms 6v 10ms -6v) ENDREPEAT Regards, Andy
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Re: Need triangular wave with using PWL mode
PULSE(-6 6 0 5m 5m 1p 10m)
...kevin On Wednesday, May 21, 2014 4:42 PM, "mete.90@... [LTspice]" wrote:
?
Hello guys,
I tried so hard but i can't do that. Can anyone send me PWL code of -6 to 6V 100Hz trianglular wave.
Thanks a lot. Regards, Mete
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Need triangular wave with using PWL mode
Hello guys,
I tried so hard but i can't do that. Can anyone send me PWL code of -6 to 6V 100Hz trianglular wave.
Thanks a lot. Regards, Mete
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Hello Sven,
After you have decided which plot(s) is the best, you can plot only one or a few of them using the @ selector.
V(out)@12
V(out)@23
Best regards,
Helmut
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Hi John,
I want to analyze just one signal point in 27 variations. Just to understand which influence have my 3 potentiometer in 3 different positions.
Helmut's way works great. Even if I only have 4 or 5 curves, LTSpice does not tell me which curve is which.
On the .tr directive it gives you the name and color.
On the .ac directive it does not.
Thanks for the help anyway.
Sven
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Thanks Helmut,
works great.
Sven
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In message <llj28q+1ji2evs@...>, dated Wed, 21 May 2014, "helmutsennewald@... [LTspice]" <LTspice@...> writes: 1. Attach a cursor to e.g. V(out).
2. Use the up/down arrow key of he keyboard to jump to the waveform you are interested.
3. Move the mouse cursor near the waveform-crosshair. The mouse cursor will then change to 1, if it's the first of the two possible cursors. Now right mouse click.
LTspice will then report: Cursor 1: a=... b=... c=... (Run 7/15) Not quite as difficult as I thought, but with 27 curves it must need steady hand with the mouse. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Nondum ex silvis sumus John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
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Hello,
Copy the file LM6172.MOD into the folder of your schematic.
Place an opamp2 from [Opamps] in your schematic.
Change the text opamp2 to LM6172/NS .
Include the model file with the SPICE-directive below.
.inc LM6172.MOD
Never place your schematics in the path C:\Program .... You will not have enough rights in this system path.
Best regards,
Helmut
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In message <llj19s+16o17n9@...>, dated Wed, 21 May 2014, "1sailingbear@... [LTspice]" <LTspice@...> writes: I am new here and have a newbie question.
The .ac analysis of my tube schematic shows 27 graphs as I run 3 potentiometer with a step directive:
.step param a list .1 .5 .99
.step param b list .1 .5 .99
.step param c list .1 .5 .99
The Graph has now 27 lines in different colors. Where can I find which color belongs to which settings of my potentiometer? It is possible, I think, but rather complicated. But do you really need all 27 curves on the same plot? You can have more than one plot on the screen (tiled) and you can choose which curves to display on each. With the screen focus on a plot pane, View => Visible traces. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Nondum ex silvis sumus John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
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Hello Sven,
1. Attach a cursor to e.g. V(out).
2. Use the up/down arrow key of he keyboard to jump to the waveform you are interested.
3. Move the mouse cursor near the waveform-crosshair. The mouse cursor will then change to 1, if it's the first of the two possible cursors. Now right mouse click.
LTspice will then report: Cursor 1: a=... b=... c=... (Run 7/15)
Best regards,
Helmut
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I am new to LT spice. I want to use the component LM 6172 in my schematic, I have downloaded the include file from the the path and used a generic opamp2.asy. However, the attributed is same as general opamp even after including the file. Could you help me how to solve this problem? Also, the way to include the .MOD extension file in LT Spice found in the group.?
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Hi there,
I am new here and have a newbie question.
The .ac analysis of my tube schematic shows 27 graphs as I run 3 potentiometer with a step directive: .step param a list .1 .5 .99
.step param b list .1 .5 .99
.step param c list .1 .5 .99
The Graph has now 27 lines in different colors. Where can I find which color belongs to which settings of my potentiometer?
Regards Sven
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Re: Pull-Push transformer for valve amp in LTspice
No, it wasn't about basic usage such as this, I think it was about analogspiceman's "xfrmr" library, two primaries for a push-pull or similar, some year or two ago. I tried to search the archives but I couldn't find anything. It doesn't matter, anyway, the OP got his answer.
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Re: Pull-Push transformer for valve amp in LTspice
? ?"...?I really can't escape the feeling there was a topic somewhere about some impossibility of having two primaries in a transformer.?"
There may be special cases. ?Other than that, though, coupled windings are just windings and it makes no difference whether you call one a primary winding or a secondary winding. ?LTspice correctly handles more than two coupled windings, no problem.
One special case where two primaries can be a problem (if modeled incorrectly), is the not-uncommon dual-voltage power transformer, which has two primary windings that are connected either in parallel or in series, to adapt to the AC mains voltage in your country. ?If you model the primary by simply taking two inductors with no resistance, and connect them in parallel, LTspice will complain about that, and quit. ?It is a legitimate complaint, because paralleled lossless inductors and/or voltage sources are not allowed in SPICE ... easily fixed by adding any amount of series resistance in each winding.
I vaguely recall another situation in this email list, where someone was using a bizarre mixture of both inductors and controlled sources to represent his transformer. ?(Recall that transformers can be modeled using EITHER coupled inductors, OR a network of resistors and controlled sources (google "ideal transformer model"). ?This one haphazardly combined both.)
Regards,
Andy
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