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Re: Ferromagnetic core modeling.
vOn Mon, Dec 23, 2024 at 04:06 AM, Tony Casey wrote:
For those not listed, there is Character Map.But again, that's Windows. ?
And anyway, I might be wrong but I thought Windows dropped the Character Map tool, another one of its dumb ideas.? I saved my copy so I can still use it.
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Personally, I don't mind when I see "u", which was in the LTwiki.? LTspice lets us use "?" but sometimes that gets us into trouble.? That happened a lot in this group when it was on Yahoo!Groups due to its online editor.? I think Helmut changed his LTspice settings to not use "?", to avoid that problem.
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Andy
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Re: Confused, adding a pin to an existing Symbol and .cir
On Mon, Dec 23, 2024 at 03:57 AM, Tony Casey wrote:
Still seems a lot of trouble to go to for each pot. I'm curious what's wrong with Helmut's old (but excellent) pot library? That uses a wiper position, which can either be a numeric (default 0.5), or you can replace it with a parameter, which is unique to each pot. Maybe Dave needed to control the pot using a voltage, so that it can change dynamically.
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I think there must be a dozen or more (perhaps dozens of) potentiometer symbols and models already.? Surely some of them might already use a control voltage that is not a hidden node.? If that was the aim, even if one did not exist already, it should have been easy to make one.
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I think Dave's attempts got several things wrong.? I think he tried to use a Comment (Vpct, Vpct2) as if it were a parameter (Comments are always ignored), and he defined two subcircuits with different names (pot, pot2), when in fact they used the same symbol so both instances actually have the same name (pot), making the second subcircuit definition meaningless as there was nothing to call it.? I think it would have been simpler to just add a 4th pin to the pot symbol for connection to the controlling voltage node.? Why make it harder than it needs to be?
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Andy
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Re: Ferromagnetic core modeling.
¿ªÔÆÌåÓýOn 23/12/2024 00:18, John Woodgate
wrote:
You can usually write '?' in email and elsewhere using ALT-0181 on the numeric keypad.If you use Thunderbird as your email client, there are a number of characters and symbols you can add from the menu item: Insert > Characters and Symbols > Common Symbols. The drop-down list contains "?". For those not listed, there is Character Map. -- Regards, Tony |
Re: Confused, adding a pin to an existing Symbol and .cir
¿ªÔÆÌåÓýOn 23/12/2024 00:06, Bell, Dave via
groups.io wrote:
Never mind, I finally figured it out:Still seems a lot of trouble to go to for each pot. I'm curious what's wrong with Helmut's old (but excellent) pot library? That uses a wiper position, which can either be a numeric (default 0.5), or you can replace it with a parameter, which is unique to each pot. -- Regards, Tony |
Re: LMH6321 Buffer Not Working
¿ªÔÆÌåÓýIt is now working properly. Helmut had an LMH6321.zip demo in the files section. His model was an older one that was only slightly different, but I was able to make my model and asy files work together. Thanks for your help, still learning. Steve ?
On 2024-12-22 18:23, Craig Lambert via groups.io wrote:
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Re: Looking for ideal fully differential amplifier spice model
On Sun, Dec 22, 2024 at 10:50 PM, Tom wrote:
... here: ?/g/LTspice/album?id=299674 ?
Specifically, here:
Photos > Delta-Sigma Converter > 2024-12-22_224815.jpg
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Andy
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Re: Looking for ideal fully differential amplifier spice model
It's primary use is for XSPICE mixed-mode simulations. For XSPICE the key is simplicity so simulation times are reasonable. I needed something quick to replace the original code model used in a Sigma-Delta converter example. I look forward to better models with user configured parameters.? |
Re: Whither 4053_tercio.asy
I located the missing pieces.
All of the examples work now.
Try again, please.
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All for now ?
Sent:?Sunday, December 22, 2024 at 12:29 PM
From:?"Jerry Lee Marcel via groups.io" <jerryleemarcel@...> To:[email protected] Subject:?Re: [LTspice] Whither 4053_tercio.asy ? Le 22/12/2024 ¨¤ 15:04, eewiz via groups.io a ¨¦crit?:
Except the model and symbol for CD4024 that are needed to run most of the circuits! ? |
Re: Ferromagnetic core modeling.
On Sun, Dec 22, 2024 at 05:16 PM, Richard Andrews wrote:
Neither.? Square meters, or meters squared. ?
See your LTspice Help page for Inductors:
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A = Cross sectional area, Units = meter**2 (meters squared).
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If even says so in the text you quoted from the LTwiki: "A is the bead magnetic cross section in square meters".
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Fair-Rite's datasheet uses millimeter dimensions so needs to be converted to meters.? Computing C*(A-B)/2 to get area in meters^2 means adding a 'u' multiplier to the computed area when using Fair-Rite's datasheet dimensions.? (Note that the "A" dimension on Fair-Rite's datasheet is not the "A" parameter in the Chan model.? You probably knew this already.)
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Andy
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Re: Separate from .CKT for .lib file
Also -
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What is this .CKT file you keep talking about?
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Presumably your SPICE model for the part is in the .LIB file, and only in the .LIB file.? If that is the case, then the .CKT file is not part of the model.? Maybe the .CKT file is something needed by PSpice or some other simulator.? LTspice doesn't need that file.
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I'm not saying that LTspice never uses a .CKT file.? If the part's SPICE model was in the .CKT file, then that is the file LTspice needs.? It doesn't care what is the filename extension.? But because you also have a .LIB file, chances are very good that the .LIB file is the SPICE model and the .CKT file is not.
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It would not be unheard-of to have parts of a model in both files.? Very unusual, but not impossible.
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The best way to tell is by looking at what's inside each file.
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Andy
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Re: Separate from .CKT for .lib file
On Sun, Dec 22, 2024 at 08:35 PM, Mirza wrote:
It would be pointless for anyone to show you an example like that.? Every circuit is unique.? "All" you need to do is identify the parts that belong to the photodiode and to the amplifier, and delete one of them.? Deleting things from the model file means literally deleting lines of text.
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Since you can't share the model file with us, there is no way anyone here can do that for you.? The only way to tell which parts belong to the photodiode and which parts belong to the transimpedance amp, is to actually SEE it for ourselves - which we can't do.? You are on your own.? Sorry.
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Chances are good that the photodiode part is smaller, so it might be easier to single it out.? It might be as simple as one line in the model file, or it could be dozens of related lines.
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Then in that case, I think you are in trouble.? Can you find another engineer where you work who understands SPICE netlists and is covered by the NDA and can help you with this?
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SPICE netlists are not hard to figure out.? For example, any line starting with "R" is a resistor.? "D" is a diode.? The first letter is always the key.
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Andy
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Re: LMH6321 Buffer Not Working
On Sun, Dec 22, 2024 at 05:54 PM, <info@...> wrote:
I think there is nothing technically "wrong" with the symbol file and model you uploaded.? I created a schematic and added your symbol to it (after editing the file's location since that is unique to your computer), and the simulation ran without errors. ?
However, you did use the SpiceModel attribute, which is NOT what I recommended using.? You should have used the ModelFile attribute instead, to specify what model file is to be loaded.? What you used was an "exception" case, and it's risky.? If you get any of the parameters wrong, it might not work the way you wanted it to work.
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If you edited your symbol after adding it to your schematic already, you may need to delete the symbol from the schematic and then add it back (not Undo, but actually adding a new one).? There are some properties that are "sticky" and may remain even if you later alter the symbol in the symbol editor.? The schematic might retain the old ("sticky") value.
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Andy
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Re: Looking for ideal fully differential amplifier spice model
On Sun, Dec 22, 2024 at 11:20 AM, Tom wrote:
Hmm.? I don't see anything to control the bandwidth.? So it is theoretically flat with 160 dB gain from DC to light. ?
It might work.? Or it might not.? Any good op-amp, either a model or real, should have a dominant pole giving it a controlled roll-off as you go up in frequency.
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And of course the model has no supply voltages, so its inputs and outputs are compliant to +/- infinity - which could be how you want an ideal model to be.
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Andy
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Re: Separate from .CKT for .lib file
Thank you very much for your advice.
Because of NDA with the company I got the file, it is difficult for me to upload the file.
Can I find any example where the lib file is separated according to the components?
I am sorry for the confusion about "The lib file has many raw data which are unknown to me".
I meant I do not understand the meaning of contents o fckt or lib file.
For example, there are hundreds of lines and each lines have meaning.
By seeing these lines, I do not understand and also which lines belong to photodiode and which lines belong to transimpedance amplifier.
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I am sorry for my poor knowledge about it.
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Re: Looking for a working closed loop LLC Converter
I have designed a good number of power supplies, but I would not attempt an LLC without a good theoretical background.? There are few specialists that crank out these designs and they usually know a great deal about the magnetics as well as the theory. ? ? Mike
On Tuesday, December 17, 2024 at 06:31:46 AM CST, zhengsq1989 via groups.io <zhengsq1989@...> wrote:
Hi Tony,
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thank you! study in progress.
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Regards,
Shengqiao
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LMH6321 Buffer Not Working
¿ªÔÆÌåÓýThose two files don't help, I think. We need
the .ASC, and please ZIP files if there is more than 1 to
upload. On 2024-12-22 23:01, Group Notification
wrote:
-- OOO - Own Opinions Only Best Wishes John Woodgate Keep trying |