开云体育

** BEWARE **

This may be old news, but got an e-mail just now purporting to come from Yahoo, to update member information, going to the link, first thing you are asked to do is enter member name / yahoo e-mail & password.

It doesn't come from Yahoo it's a completely different web site, (only need to see what this is in browser's web address line, but don't post the form!)

I.e. it's a phishing scam

Just click Yahoo 'spam' button to dump the e-mail and notify Yahoo.

HTH

Hello Shiggy San,

I have now deleted two the two members below from the group.
I hope this solves your problem.

mr.shigematsu@...
mr1.shigematsu@...

Please make a new membership for the LTspice group. You can make
it even with the same name and email address.

Best regards,
Helmut

--- In LTspice@..., "yhocom_7" <greg-brenda-nelson@...> wrote:

LTspice,

I need to create an arbitray waveform generator that will be used for simulation. I need to have the discrete steps that a D/A would present to my system. Is it possible to feed a text file(at a specific rate) to a simulation and turn on/off current sources. I need to have several text files(waveforms) to experiment with.

I will "try" and create an example asc file and upload. I will call it AWG.asc

Thanks,

GDN
-----------------------------------------------------------


Example ramp text file for 3 bit D/A.

000 t1
001 t2
010 t3
... tn
111 tn+1

Hello GDN,

You might want to check what the Helpfile says about PWL sources. Additionally, there is a raft of prior art in the files area of the group site:


Regards,
Tony

--- In LTspice@..., "Gandolf" <charlesknouse27@...> wrote:

I have uploaded to MATURIN TEMP folder an .asc for testing a subcircuit I found for the 1.225 volt reference: TLV341.

I can't get it to work right. I'm doing something wrong, probably the order that I have the terminals to the .asy in the circuit, but I can't figure out where I've gone astray.

Help greatly appreciated.

VB, Maturin

Hello Maturin,

I think you mean TLV431, not '341...

You forgot to upload the Vref symbol. I happened to have a symbol for a TL431 I prepared earlier. That did have a different netlist order, so I swapped it over. It didn't work.

Your model shows evidence of having been messed about with, so I quickly gave up, given that there are several working models and test circuits in the files area:


and


Did you not look there first?

Regards,
Tony

I cannot find a model for electrical contacts that simulates bounce. I do not need a full relay simulation with coils and such. I only want to model the electrical contacts of a reed relay with bounce.

LTspice,

I need to create an arbitray waveform generator that will be used for simulation. I need to have the discrete steps that a D/A would present to my system. Is it possible to feed a text file(at a specific rate) to a simulation and turn on/off current sources. I need to have several text files(waveforms) to experiment with.

I will "try" and create an example asc file and upload. I will call it AWG.asc

Thanks,

GDN
-----------------------------------------------------------


Example ramp text file for 3 bit D/A.

000 t1
001 t2
010 t3
... tn
111 tn+1

Hi Helmut-san!

Sorry for my before email.

I will make new regisration.
The the registration of using the mr.shigematsu@... is not permitted
within
90 days, I think.

Shiggy



2012/9/1 重松宏昌 <mr.shigematsu@...>

Hi Helmut-san!

Thanks your email.

If you don't know how delete that, pelase tell me all your

names you login to the LTspice group and I will do that for you.
<---This is my answer.
---------------------------------------------------------------
My address: mr1.shigematsu@...

ID: mr.shigematu or mr.shigematsu@... <--- I think one of two is
correct.
---------------------------------------------------------------

If sossible, I want have new login ID.
And I want to make every information in English

Shiggy



2012/9/1 Helmut <helmutsennewald@...>

**


Hello Shiggy,

I wonder why you make things so complicated. Please delete
all your memberships to the LTspice group.
If you don't know how delete that, pelase tell me all your
names you login to the LTspice group and I will do that for you.

After you have deleted all, then simply make a new membership
for the LTspice group.

Best regards,
Helmut
Moderator

THANKYOU. Did I just learn something about Windows and Help programs LOL?

In any case, I have Help now...LED's, watch out! :)

VB, Maturin

Open the folder where you extracted the files too, right click on the
"diodemodelingtool.chm" file and choose properties, click on the "unblock"
button.

Dave Wade G4UGM
Illegitimi Non Carborundum

I have uploaded to MATURIN TEMP folder an .asc for testing a subcircuit I found for the 1.225 volt reference: TLV341.

I can't get it to work right. I'm doing something wrong, probably the order that I have the terminals to the .asy in the circuit, but I can't figure out where I've gone astray.

Help greatly appreciated.

VB, Maturin

Hello Shiggy,

I wonder why you make things so complicated. Please delete
all your memberships to the LTspice group.
If you don't know how delete that, pelase tell me all your
names you login to the LTspice group and I will do that for you.

After you have deleted all, then simply make a new membership
for the LTspice group.

Best regards,
Helmut
Moderator

Hi Akituki-san!

I have alrady red your email now.
But I can not understant it almost.
Sorry.

So I describe my situation in bellow.
And also I have uploaded the bellow 2 tiles filws to explaine my situation.

My Contact information and Login ID which is displaied at of top page
can not be changed(modified).

Yahoo_login.png <--- There is garbled character.
Yahoo_contact_info.png <--- Can I change this information?
Because there was a word of Update, so
I am considering the change.

Another question.
Yahoo people give me bellow message for my login of mr.shigematsu@...
.
----------------------------------------------------
Oops! There is a probrem (#77309)
You are trying to add an email address that has been blocked by the email
address owner.
Please enter a different email address.
-----------------------------------------------------
Does this means that "I have delete the my email address?
-----------------------------------------------------

I am in trouble, so I can not English statement almost.
If possible, I want to control my information or profile.

Shiggy
PS: I can access the File by using the mr1.shigematsu@... now.



2012/9/1 Masahiro Akizuki <m.akizuki@...>

At Tony's marvelous suggestion, I went to:



and downloaded the files. I have the program for modeling diodes installed, and have downloaded the Help file/program, but I can't get the Help to run. It gives the error message something to the effect that "access to the webpage has been canceled"

Can anyone help me get this help to work? I didn't cancel anything that I know of, and I downloaded the Help again and tried to open it a second time, but not luck.

I did my best to "fly blind" with the program, but it also gave me an error, saying one of my values was non-computable. Since I had done my best to take the values right from the datasheet graph, I need the Help to help me figure out how to make it work.

VB, Maturin

Hello Shiggy

I understood that Andy said Yahoo's LTspice Group? could access from Gmail.
If you can log in to Yahoo's LTspice Group, your member ID can check? at Members tag in LTspice page.
And input your ID in the search column.
My ID can check the above method.


I recommend your name will change fromJapanese Characters to ASCII characters, because almost all members use
English.

Best regard
M. Akizuki

?



________________________________
From: 重松宏昌 <mr.shigematsu@...>
To: LTspice@...
Sent: Friday, August 31, 2012 11:23 PM
Subject: Re: [LTspice] Re: I can not access the File of LTspice.

Hi Everyone!

In this matter, I can not recognize the your sentence conccerning this
matter.
note) I can only understand the sentence conccerning the Enginearing.
I am sorry.
Because I am poor for English.
I have started to read the Yahoo! Document(for eample SIN2059).

When I have successed to control the Yahoo!'s email system(ID and mail
adress, Acount),
I will tell you.

Shiggy



2012/8/30 Andy <Andrew.Ingraham@...>

**


Vlad wrote:

The Gmail IDs can be used to login into Yahoo, the Group settings allows

for using a Gmail or a Yahoo email address as the primary one.

Interesting! That is news to me. Thanks.


Shiggy-san wrote:

Q1) Would you tell me the method of ascertain the yahoo ID.

I can see that you used the Yahoo! ID of "hiromasashigematsu".when you
posted your earlier messages to the [LTspice] group. (We can see that
from the Message listing.) This should mean that "hiromasashigematsu"
is the one you used when you joined the [LTspice] group, so logging
into Yahoo with that Yahoo! ID SHOULD give you access to the [LTspice]
files.

If you have other Yahoo! IDs, they might or might not also be "signed
up" for the [LTspice] group (depending on whether you also joined this
group from those Yahoo! IDs too). You must use a Yahoo! ID that has
joined the [LTspice] group, because the group's files are accessible
only to members who have joined the group.

If you can see the files, but can't download them (as others have
suggested), then I don't know why. That is very strange.

Good luck!

Andy

?

[Non-text portions of this message have been removed]



------------------------------------

Yahoo! Groups Links



[Non-text portions of this message have been removed]

--- In LTspice@..., "Tony Casey" <tony@...> wrote:

--- In LTspice@..., "Gandolf" <charlesknouse27@> wrote:

After searching LTspice files exhaustively for LED models, it seemed to me that the best ones were Helmut's, i.e. this one for a GaAs LED:

*Typ RED GaAs LED: Vf=1.7V Vr=4V If=40mA trr=3uS
.MODEL Red_Led_660nm3mm D (IS=93.2P RS=42M N=3.73 BV=4 IBV=10U
+ CJO=2.97P VJ=.75 M=.333 TT=4.32U)

The LED I wish to model is the WP710A10SRC/E from Kingbright (3mm GaAs 660 nm); there are some small but (because I'm stringing a lot of 'em ;) important differences from the model above...

....namely, 1.85 typical Vf at If=20 mA typical, 30 mA max, 45 pF capacitance, 10 uA reverse current (and unfortunately, that's it from the datasheet!!).

Would someone please explain what all the parameters are between the parentheses in Helmut's model above and how I change them to better simulate the Kingbright LED? I searched for LED spice parameter's, but could not come up with any info on what IS, RS, N, BV, etc, stand for.

Very Best, Maturin

Hello Maturin,

An LED is just a diode, as you get glean from the .model line you quote above. I don't know where you searched for the model parameters, but they are all listed in the LTspice Helpfile under "diode", and elsewhere - for example, the PSpice manual.

The most convenient way to generate a diode model is the use Henrick Jan Zwerver's Diodemodeller software located in the file area:



You can then tweak the parameters within LTspice, if desired, when plotting the characteristics in a device jig.

Regards,
Tony

Ah, thanks, Tony, this is much better - a way to model the device using the graphs in the datasheet.

VB, Maturin

--- In LTspice@..., rainbowsally wrote:

I love the schematics (especially analogspiceman's.. :-) They
are beautiful.

Thanks for the kind remark. :) :)

Like my posts, I *do* try to make my schematics sensibly organized
and easy to read (but sometimes I fear I forget to mention that I
have decreased the default font size). Understanding electronics
is already difficult enough without having to look at a messy,
jumbled schematic.

But I'd like to literally see how some of these subcircuits are
modeled so I can see why things behave as they do. [...] How do
I get a visual representation of the components MINUS the *.asy
file. And I don't care how many steps it might take. Might even
write a converter program if there isn't a way to do this inside
LTspice.

Drawing them component by component is on my don't-do list.

Uh-oh, then I'm afraid you may be in for a disappointment.

Here is what I do, but it is very laborious (so it's worth the
trouble only if the netlist is very interesting).

Before you start, make working copy of the netlist and then clean
it up by doing any reordering of lines or shortening of node/net
names that will make them easier to work with. For example, nets
with names like "n023" and "n001" can usually be safely shortened
to "n23" and "n1" (sometimes I do this in a word processor with
find and replace). Also, it is a good idea to move all comments
to the end of the working netlist (if not delete them altogether).

At this point, I like to import the netlist into LTspice, either
directly onto the schematic (if the netlist is short) or into a
separate LTspice netlist window. (Did you know that LTspice has
its own netlist viewer that displays text in context aware color?)

Now go through the netlist line by line and place a component of
the corresponding type on the schematic (arrange these in rows by
component type such that you build up rows of all the same type).
It is important to do this in exactly the same order as the net-
list because this will greatly ease cross checking when you think
you have finished. (Also, all of the SPICE text, such as model
statements, etc. should be copied and pasted in at the end.)

As you place each component, edit its reference designator to
agree with the corresponding netlist reference designator.

As you place each component, place a net-label/node-name directly
on each pin of the component (of course, these should agree with
their names in the netlist, too). Don't bother with wires yet as
these will just be trouble to move around later.

Once all the components are placed, view the SPICE Netlist (it's
a drop-down menu item) and verify that it agrees *exactly* with
the original netlist (it will, if you followed these instructions
carefully). Correct any errors as needed until agreement is
perfect. This "schematic" should actually be able to run at
this point.

So far you have just been playing the part of a robot, but now
comes the fun part where human judgement is required. Move the
components around on the schematic to group them such that the
pins that have the same net names are close to each other and
that signal flow makes sense. Use the Highlight Net tool (right
mouse button click on a pin or net) to make sure no connection
is overlooked.

Only when the parts are reasonably well placed is it time to
start drawing in the wires and adjust the look of the schematic.

Be sure to check occasionally that the two netlists continue to
match.

Because both netlists and schematics are just ascii text files,
the first part of this process should be fairly straightforward
to automate in software. Grouping components and connecting them
for least total wire length might be harder, but still possible
(I would try an approach using the so-called "synthetic annealing"
algorithm). However, finishing the schematic to human sensibilities
would seem beyond the reach of any canned program, but having a
utility that did the first two steps would be a big time saver and
well worthwhile. -- a.s.

PS: If you wish to write your own code to do this perhaps it
would help to look at this very similar open source program
(unfortunately it does not produce LTspice schematics).

Hi Tony,

You cannot save an array of measurements, unfortunately, so you
will need a .meas statement for each frequency of each parameter
you want to save. If there are a lot, it might be better to put
all the .meas statements into an .included file to save
cluttering up your schematic.

I'm not sure if that is totally true - depending on what you
define as 'an array of measurements' :)

You can use a .step statement and then extract the step details
from the .raw file. I wrote examples for .tran and .ac analysis
here:



I mention this in case its a method you have not tried before.

Thanks for the Matlab example - I'll get around to trying that
sometime. I assume it will work after a fashion in Octave, as Matlab
is beyond my budget.

Try Octave and see. If you have problems, let me know and I'll
track down the issue.

Note that you can run the LTspice circuits in the example zip file
without processing the data using MATLAB. The point was for you to
see how the values of the stepped variable can be saved.

Unfortunately, it won't be much use in this case because although you
can coerce LTspice into using a .step param Freq construct in .AC,
the Freq array doesn't seem to be available for .meas postprocessing.
I tried it and Freq always just returns the last value in the range.

Right, I had that same problem. If you look in the LTspice circuits
in the MATLAB example zip file, you will see that the solution is to
use a voltage source to write out stepped parameters into an *extra*
array. Post processing of the .raw file can then be performed using
the data normally written to that file, and the *extra* array of
stepped values.

Cheers,
Dave

Hi Everyone!

In this matter, I can not recognize the your sentence conccerning this
matter.
note) I can only understand the sentence conccerning the Enginearing.
I am sorry.
Because I am poor for English.
I have started to read the Yahoo! Document(for eample SIN2059).

When I have successed to control the Yahoo!'s email system(ID and mail
adress, Acount),
I will tell you.

Shiggy



2012/8/30 Andy <Andrew.Ingraham@...>

**


Vlad wrote:

The Gmail IDs can be used to login into Yahoo, the Group settings allows

for using a Gmail or a Yahoo email address as the primary one.

Interesting! That is news to me. Thanks.


Shiggy-san wrote:

Q1) Would you tell me the method of ascertain the yahoo ID.

I can see that you used the Yahoo! ID of "hiromasashigematsu".when you
posted your earlier messages to the [LTspice] group. (We can see that
from the Message listing.) This should mean that "hiromasashigematsu"
is the one you used when you joined the [LTspice] group, so logging
into Yahoo with that Yahoo! ID SHOULD give you access to the [LTspice]
files.

If you have other Yahoo! IDs, they might or might not also be "signed
up" for the [LTspice] group (depending on whether you also joined this
group from those Yahoo! IDs too). You must use a Yahoo! ID that has
joined the [LTspice] group, because the group's files are accessible
only to members who have joined the group.

If you can see the files, but can't download them (as others have
suggested), then I don't know why. That is very strange.

Good luck!

Andy

[Non-text portions of this message have been removed]

--- In LTspice@..., "yogasmitha" <amba_200@...> wrote:

Hello Rick,
Thanks, But i have connected the ground on the R285 to R295 resistors. Which is ground. Do you think there has to be some big resistor at the return path? say 100K since the input and the output side will have a common grounds and as i said it will short the return path?

Do you have any other source or database which can give me the esr of the caps i am using.
SInce i know these will contribute a lot to the instability.

another thing i want to know is " i have used the inductor as a flyback transf and want to know if the series resistance is calculated by the ltspice tool on its own"
i have given the direct values of 0.045Ohm what is given in the datasheet. What actually is seen by the coil is based on the connectivity. i.e parallel or series etc.., Will lt tool calculate on own since the coil craft vendor told me the LT tool will do. I just wanted to clarify once with you.

What are the other values/components which affect the stability of the flyback?
Should i try to do something with the comp pin(values) of the LT1241 device?

Ple Help.
Thanks,
Yoga

Yoga,

You're right, you do have a connection there. When I looked at your circuit before, I saw a very large voltage between ground and the common bus on the bottom half of the circuit. This caused by the inductance between ground and the common bus and the very larges start up currents in the circuit. I removed UIC from the .TRAN command and the startup currents were greatly reduced. (You could do this other ways, but this was easy to do.) You should revisit your filtering scheme.

After I removed UIC, the circuit seemed to behave OK. Specifically, what do you think is wrong?

LTspice contains a library of caps with their ESRs. In addition, part manufactures specify ESR.

LTspice does not compute the inductor series resistance but it defaults to .001 ohms for inductors that are not mutually coupled to others. LTspice also has a library of inductors, and vendors specify performance. The model LTspice uses for an inductor is given in the help file.

Rick