Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- LTspice
- Messages
Search
|
Re: Ideal Swich Model missing
martin562284
--- In LTspice@..., "analogspiceman" <analogspiceman@...> >
Well, people keeping complaining about Help, but so far no one,I posted a suggestion as to how we could collaborate on maintaining/improving the help document just a few days ago - Message no. 49532. |
|
Re: Ideal Swich Model missing
--- In LTspice@..., "Lewis" <lineblp@...> wrote:
LTwiki.org <> is now fixed on the front page withHello Lewis, Some of the spammers were ferocious in their persistence, weren't they? They seemed to have had a perplexing, particular interest in the section on transformers. Never understood that. Perhaps they thought that name would attract a lot of visitors from non- techies searching for the fictitious type of "Transformer" (as in the films). Anyway, we have never really net-formally met. I believe I've seen one of your email addresses over at the LTwiki, so I will have to send you a message. By the way, I didn't have any trouble signing up - just took a very small amount of poking around to find the right page. I found it much more difficult to find the specialized wiki language help pages (most html also works at the wiki, by the way). Perhaps I will add a direct link to the wiki help as well. I don't think anyone needs to be a wiki language expert to start contributing to the LTwiki as an author may just describe what the appearance of their contribution should be and somebody else will probably add the wiki polish if the underlying piece is compelling. The most important thing is to write well, concise and clear. There is a built-in editing tool set for the most common commands (such as basic text formatting and the creation of hyperlinks), so the mechanics of contributing soon become easy enough. Perhaps we could set up a Help file replacement (many bits are already in place). Many sections would likely mimic LTspice's Help system and at least start out by heavily borrowing directly on the existing Help, so I wonder if permission from LTC would be required? If so, I think you be a more diplomatic choice than me to ask Mike. Regards -- analogspiceman |
|
Re: model, subckt tube EC81 = 6R4
Ganesan
Maybe this will help..
toggle quoted message
Show quoted text
"Spice Models for Vacuum Tube Amplifiers" AES, March 1995 Cheers A. Ganesan On 9/16/2011 7:24 PM, Charly Engineering wrote:
|
|
Re: Ideal Swich Model missing
Lewis
LTwiki.org <> is now fixed on the front page with a
link on how to create an 'account'. This capability also exists if one tries to 'log in'. Sorry, I did not try to make it hard, only the anonymous spammers were taking many hours of my day to roll back their destructive work. Create an LTwiki account <> Thanks everyone for a great online community. Lewis --- In LTspice@..., John Woodgate <jmw@...> wrote: how.I would be delighted to contribute to the Wiki, but its not clear The front page of the Wiki says "create an account to contribute" butIf so, it needs to be fixed. |
|
Re: Ideal Swich Model missing
Hello Jim,
toggle quoted message
Show quoted text
I agree it should be easier to find help when one needs it. In your case how to create an account on LTwiki. But then once the account is created, the instructions how to do so become irrelevant and thus clutter. So a bit of poking around reveals that signup info is in LTwiki - toolbox - special pages - Login / signup. As one wise old sage remarked - ...there must be a pony here somewhere! It is just up to us to find it. As frustrating as it is, I have resigned myself to this a long time ago. Respectfuly ME --- In LTspice@..., Jim Wagner <wagnerj@...> wrote:
|
|
Re: plotting magnetic field
--- In LTspice@..., "samadamsspam" wrote:
I'd like to add a trace for the magnetic field for a coil to mySchematic parameters are not available to the Waveform Viewer, but you could set up a voltage source with its value set to {N} (be sure to include the curly braces). Label this node "N" as well, so that the Waveform Viewer will know it as V(N), which you may then use in waveform arithmetic. -- a.s. |
|
Re: Time varying coupling coefficient for any 2 inductors
--- In LTspice@..., Ganesan <dg1@...> wrote:
Here is how you use the time varying transformer for any twoHere is the correct way to link to files in Temp: And your ideal transformer file: These files have errors. The "n" and V(x) term in the controlled current source are inverted and you should scale the output inductance by the square of n. Also the inductances should be equal to (1+V(x))*L_nominal (because when they are 100 percent coupled they are in parallel). -- a.s. |
|
plotting magnetic field
I'd like to add a trace for the magnetic field for a coil to my waveform plotting, and not sure how to do that.
I have created a parameterized "step" simulation which steps over the inductance of a coil. I calculate a parameter for the number of turns for the coil, which I call N. I'd like to plot coil current * N, along with other circuit varibles. I thought maybe a user defined function could be used, but I don't know how to reference my variable N to pass it to the function in the "Add Trace" dialog box. My paramter definitions for the simulation are: .step param Lcoil list 1m 2m 4m 6m 10m 16m .param Rcoil = 9.8 * sqrt(Lcoil * 1000) .param Cres = 1 / (4 * pi * pi * Lcoil * 14.5k * 14.5k) .param C2 = 1.1 * Cres .param C1 = 10 * C2 .param N = Rcoil * 100.0 / 24.0 .meas Rcoil_ param Rcoil .meas Cres_ param Cres .meas C1_ param C1 .meas C2_ param C2 .meas N_ param N Can anyone suggest how to do this? Regards, -SAS |
|
Re: Time varying coupling coefficient for any 2 inductors
Ganesan
Here is how you use the time varying transformer for any two inductors..
toggle quoted message
Show quoted text
File --->Temp--->Non_ideal_inductors.asc <> cheers AG On 9/16/2011 5:59 PM, Ganesan wrote:
|
|
Re: Current Sensor
--- In LTspice@..., "danfly09" <da.nc3262@...> wrote:
I'm looking for a hall effect current sensor like the ACS712. You are in luck. Here is a subcircuit I made, but you will have to make your own symbol for it. Change the gain parameter to corresponding to the dash number of interest. -- a.s. .subckt ACS712 I+ I- Filter Out V+ V- .param gain=185m; 185m -05B, 100m -20A, 66m -30A V1 I+ I- 0 F1 V- 2 V1 {gain} T1 1 V- 2 V- Td=1u Zo=1 R1 2 V- 1 R2 Filter 2 1k7 G1 V- 3 Filter V- 1 C1 3 V- 1?3 Rpar=1 R3 Out 3 50 G2 V- 3 V+ V- 0.5 R4 V+ V- 2k .ends ACS712 |
|
Re: General SPICE environment setup
Lewis
For those wishing to create 'permanent' LTspice parts that appear in
your drop down menu of LTspice, please reference Adding a component to LTspice - Ltwiki.org <; ice> and a section on already completed parts following this approach at Components Library - LTwiki <> Further contributions to this library are welcomed, as well. This approach has also already been included in the messages here over the years, so I won't repeat it now. It's a little different that what is called out for in scad3.pdf. These parts are portable, but you must be aware of what the symbol and subcircuit names are, that you put in a folder of the \sym directory and \sub directory. I personally add a folder below the \sym directory for my own permanent parts. Then I make subcircuit names that are easily recognizable to sync to my other computers using LTspice. To make these parts portable, and part of any design you'd want to share, just include those specified sym and sub files in the same folder (all zipped together) as your shared schematic. The receiver can keep these in the same folder as the provided schematic and all goes on as before. Alternately, they can copy these provided symbols and subcircuits to their respective folders as outlined in the wiki, and they will become their own custom permanent parts. (You must restart LTspice to see them.) Sometimes, when exchanging schematics between my desktop and laptop I'll get a little sloppy and forget I'd used one of my permanent parts. So, LTspice tells me if I try to do an analysis. The bigger embarrassment is to professionally provide a schematic, or upload on to this group - just to have it be incomplete. I hate to elaborate on this topic, as everyone here as justified strong opinions about it. But you asked - and here is my complete answer. --- In LTspice@..., eaneonakis@... wrote: not such a bad idea. Best Regardswrote:
|
|
Re: Time varying coupling coefficient for 2 inductors
Ganesan
I forgot to add..
toggle quoted message
Show quoted text
The flux doesn't collapse instantaneously... This can be modeled by putting V(X) through an RC low pass. Cheers AG On 9/16/2011 5:55 PM, Ganesan wrote:
|
|
Re: Time varying coupling coefficient for 2 inductors
Ganesan
I have modeled an ideal transformer with time varying coupling
toggle quoted message
Show quoted text
coefficient.. File is in Temp--> Non_ideal_transformer.asc <> Your feedback will be appreciated. Cheers A. Ganesan On 9/16/2011 11:02 AM, ttakeshian wrote:
|
|
Re: Current Sensor
Google is your friend. Search on the phrase "spice hall effect"
toggle quoted message
Show quoted text
Howard On 9/16/2011 4:39 PM, danfly09 wrote:
Hi, i'm looking for a hall effect current sensor like the asc712... there isn't a .lib that i could simulate?? or anything possible solution but without use a shunt resistor |
|
Re: Ideal Swich Model missing
Another problem with the LTspice Help, is that just about everything
starts with the old non-graphical input format of traditional (i.e. Berkeley) SPICE: Syntax: Sxxx n1 n2 nc+ nc- <model> [on,off]And then we tell everyone to use the schematic editor, and upload schematic files instead of netlists. So the Help file is a little like using DOS in a Windows world. Plus the references to a SPICE "deck", a model "card", etc. Imagine if the Help for MS-Windows gave everything in terms of DOS commands and command-line switches. It probably makes little sense to anyone coming to LTspice for the first time. For those of us who used SPICE before, the relationship between the element and the model, by way of the model name, was obvious. And we take for granted that the element is now a schematic symbol, but the model is a "SPICE directive" ... which is mentioned in the Help description but not really explained. So yes, there are lots of problems. Andy |
|
Re: Time varying coupling coefficient for 2 inductors
--- In LTspice@..., "ttakeshian" <ttakeshian@...> wrote:
Tony, LTspice can be used to model any system of ordinary (not partical) differential equations using "analog computer" techniques. The coefficients can be made time varying by using BV elements that are a function of time. Rick |
|
Re: Ideal Swich Model missing
John Woodgate
In message <j50avg+6kln@...>, dated Fri, 16 Sep 2011, analogspiceman <analogspiceman@...> writes:
Well, in the switch example, Help offered,I would add a few more words. 'Open the downloaded LTspiceIV folder, open examples and then Educational, and open the schematic file Vswitch.asc'.... In doing that, I've assumed no more than beginner level understanding of Windows (at least in English) as well. That dot in .\examples\Educational\Vswitch.aschides a lot of meaning. It would certainly have minimised doubt anyway, but I agree with you that 'card' [and 'deck'] are archaisms that should be eliminated. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK When I point to a star, please look at the star, not my finger. The star will be more interesting. |
Leo Baumann
to navigate to use esc to dismiss