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Re: differimproved
Marcel wrote:
? ?"With UIC one can provide a hint for the steady-state." Actually, with UIC, one does not provide a hint. ?One provides the entire steady-state operating point. ?SPICE bypasses finding the operating point and takes what you give it, as the operating point.
If you use IC= or .IC without UIC, then SPICE takes what you have provided as a hint, and continues from there to converge on a steady-state solution.
I find the reason most people use the UIC, is because of not understanding what SPICE does, or because they are simulating something like an oscillator, for which careful use of UIC can be beneficial. ?Otherwise, UIC should mostly not be used, and I don't understand why so many people seem to think that adding it is a useful thing to do.
Is PSS something that really helps analyze a DC coupled audio amplifier? ?Is there something wrong about SPICE's ordinary operating point analysis with respect to this amplifier?
Regards,
Andy |
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Re: Li-ion BAttery models
John Woodgate
In message <lmcqgn+ui7i2a@...>, dated Sat, 31 May 2014,
"thutches@... [LTspice]" <LTspice@...> writes: The only other setting that I have that could affect this is that I useI don't think that makes a significant difference. I doubt that anyone expects you to, especially now I've explained how to fix it to use a larger font size and still see everything clearly. The point is that LTspice (and probably most Spices) fixes the position of text on the schematic screen, I think, by the x-y position of the first character. So if the font size changes from a small number to a larger, especially to the default (which is actually the rather enormous Tahoma 28pt Bold), the text strings run over everything in their path. I don't think there is any better way of locating the text, short of setting up 'exclusion areas' around the schematic elements and setting the ends of strings to just touch the exclusion boundary. I think some printed circuit drawing programs do this, but it's very complicated to implement, because a string so placed might intersect another exclusion area along its length. -- 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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Re: Li-ion BAttery models
John, The only other setting that I have that could affect this is that I use the BOLD option with Arial 10-pt font, which makes it pop a little better.. So other than resetting to defaults and redrawing my schematic for this, which is entirely tangential to the original intent of pointing out the Saft model and how I used it?to the OP, I'm beyond being able to spend time on it because it seems kind of open-ended as to what satisfies others about it should look like. But I'll keep this in mind in the future. Tim |
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Re: Li-ion BAttery models
I found this, but have not tried it (yet): ? It is NOT a *SPICE model, but I plan on making one from it.
--Steven Hill Excerpt: "Because the charging process for?Li+?batteries can take an hour or longer, testing a?Li+?battery charger using its natural load is time consuming and frequently impractical. To speed battery-charger testing, this article presents a simple circuit for simulating the behavior of a?Li+?battery. This circuit provides an efficient means of testing?Li+?chargers without using real batteries.
" On Sat, May 31, 2014 at 10:21 AM, John Woodgate jmw@... [LTspice] <LTspice@...> wrote:
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Re: Li-ion BAttery models
John Woodgate
In message <lmckku+11hc6fs@...>, dated Sat, 31 May 2014,
"thutches@... [LTspice]" <LTspice@...> writes: The screenshot is OK. What is in the ZIP is an .asc schematic file, not a screenshot. All the text areas are superimposed on the actual circuit elements, so neither are intelligible. AHA! Setting the font size to 10 instead of the default fixes the problem. But it's then difficult to read the text. So MOVE the text blocks away from the schematic and increase the size until it can be read. -- 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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Re: Varicap MVAM108
> abuhafss>>Hi > >I need the LTspice model for varicap diode MVAM108 or MVAM125. >Shall appreciate if anybody can help me. > > >Best regards > >Abu-Hafss Take a look at VVC.zip on the Device Models & Subcircuits page of my website... ?????? <>
???????????????????????????????????????
...Jim Thompson
Jim Thompson
35129 North Laredo Drive
San Tan Valley, AZ? 85142
Voice: 480-460-2350?? Fax: 480-460-2142
Wearer of the Brass Rat - Class of 1962 |
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Re: Li-ion BAttery models
Phillippe, does your screen look like the screenshot I posted?? ?If not, I'd like to see what the clumsy screen version of the circuit actually looks like on another screen, so please someone upload a screenshot.? Hopefully I can learn to make my circuits "not-so-clumsy", so that If I ever post something, it doesn't create total confusion and consternation. ?:-) Thanks, Tim |
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Re: Li-ion BAttery models
All I uploaded a screen shot of how the circuit looks on my screen.? If that is what is considered clumsy, well - it is what it is. Otherwise though, I'm using Arial 10pt font.? that and some other setting in my options could be causing it to jumble up on other screens.? ??? Tim |
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Re: Li-ion BAttery models
John Woodgate
In message <lmchu0+ui59cn@...>, dated Sat, 31 May 2014, "basier.philippe@... [LTspice]" <LTspice@...> writes:
In the file you have uploaded all comments, LTspice directives, models andI suspect that the uploaded/downloaded .asc doesn't look like the author's original. I suggest he looks at it, so as to understand the problem. What has caused it? Helmut, do you have an explanation? -- 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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Re: differimproved
PSS == Pseudo Steady-State algorithm (e.g. http://www.mos-ak.org/sanfrancisco_2012/presentations/T05_Lannutti_MOS-AK_121212.pdf).? A PSS is useful for power electronics circuitry (where the steady-state is a trajectory in state-space). When the option UIC is *not* used,?SPICE?automatically finds an initial solution?at t=0. This?works (very) well for most analog (non-switching) circuits.?With UIC one can provide a hint for the steady-state. IMHO this should be faster in all non-trivial cases, but I notice that the experience of people in this forum is different. A?brute-force PSS algorithm?simply runs a .tran until you detect that the state trajectories are converging. This convergence is actually?quite?tricky to detect, especially when there is feedback involved. I hope this answers your question. -marcel |
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Re: Waveform export from Mac LTspice?
Oops. Just found it. Start in the waveform window. Then Control Panel -> Waveforms -> Data Export Tool.
If you haven't noticed, the Control Panel options are different when you start from the waveform window than when you start from the schematic window. I seem to have a hard time remembering that. |
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Re: Varicap MVAM108
Hello Abu-Hafss,
You should firstly try on the manufacturer's web pages and then with Google. I made a short and looked with Google for the MVAM125. I found by luck an example with the diode's curve fit using the formula from the diode's SPICE model. http://www.qsl.net/in3otd/electronics/varactor_model/varactor_fitting.html Files > Lib > MVAM125_test.zip Best regards, Helmut |
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Re: Security?
Come on, folks!
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If a newbie comes along and asks about security of files on the website, that person deserves a straight answer. These days, with viruses and trojans and all that stuff seeming to be anywhere, it is a prudent question. Most newcomers to spice and many who have been around a while don't know that spice files are text files. As far as the casual observer might know, a .cir file could be just as able to carry bad stuff as a .jpg or .pdf or .xls or .docx any of the other complex file structures. In today's world, I would be a lot more cautious here than I am, if I were coming as a new user. There are several factors that make bad stuff pretty unlikely, here. Or, at other spice sites. 1. The target: anyone writing bad stuff wants big impact. spice has a very small user community, compared, say, to excel or word users. It is hard to imagine much general impact, beyond simple spite or maliciousness. 2. The kind of possible exploit is very limited. The language is pretty tight, and the parser can check for violations pretty easy. There should never be a "buffer over-run" exploit or anything like that. 3. spice files are not executables. They are interpreted by the the host application (a variant of Berkeley spice). There is a long history in spice, with all sorts of unwitting attempts at mucking it up. It is pretty bullet proof. You CAN have files that appear to be one thing while are really another (an exe masquerading as a txt file). The operating systems have put significant constraints on the ability of this exploit to operate. Not impossible, of course, but, generally, YOU Have to agree to run any downloaded executable.? So, the short answer is that, if you are concerned, YOU can open any spice file with a text editor and verify that it is what it says that it is. After a while, you will discover that its an extra effort that you really don't need to take. Jim Wagner Oregon Research Electronics On May 29, 2014, at 10:24 PM, analogspiceman@... [LTspice] wrote:
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thutches