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In message <kkhgj0+b6hu@...>, dated Mon, 15 Apr 2013, "theac1@..." <theac1@...> writes:

I am trying to post a question here but for some reason LTC won't allow me to copy the error log and post it here for my actual question. Is there a way?

Assuming you are using a PC, select all the text (CTRL-A), copy (CTRL-C) and paste (CTRL-V) into Notepad or Word or something like that, or directly into your message.

You can also set up LTspice using 'Control panel' (the hammer icon) so as not to delete the .log file when you close the .asc file. It is just a text file and will appear in the same folder as your .asc file.
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
They took me to a specialist burns unit - and made me learn 'To a haggis'.

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

Please send 7493 ic's macros for LTspice

Open it with an ordinary text editor?


Jim Wagner

Hello folks:

I am trying to post a question here but for some reason LTC won't allow me to copy the error log and post it here for my actual question. Is there a way?

A..

Hi,

Problem:
How to delete *.raw files between successive simulation jobs while using the queue manager.

Background:
I use the queue manager to run Monte-Carlo sims on the same circuit with different design constraints. I form up unique file names, such as, Run1.cir, Run2.cir, Run3.cir etc... each containing a unique netlist.

Setup.ini looks like this:

C:&#92;Program Files (x86)&#92;LTC&#92;LTspiceIV&#92;scad3.exe
C:&#92;Program Files (x86)&#92;LTC&#92;LTspiceIV&#92;Dean&#92;Run_B&#92;Run1.cir
C:&#92;Program Files (x86)&#92;LTC&#92;LTspiceIV&#92;Dean&#92;Run_B&#92;Run2.cir
C:&#92;Program Files (x86)&#92;LTC&#92;LTspiceIV&#92;Dean&#92;Run_B&#92;Run3.cir

The .meas directive is used to place sim measurements into log files .i.e Run1.log, Run2.log, Run3.log .etc...

Each .cir generates a 60-90GB data file which must be deleted before the next .cir is called. This doesn't happen causing the system to run out of resources.
LTSPICE has an option to delete *.raw files upon closure of the executable but, the queue manager does not close the executable between job calls.

Two mitigations I can think of are:
1) Modify the queue manager to close and re-open the LTSPICE executable between job calls. LTSPICE can then delete the *.raw files if so requested.
2) Give LTSPICE the option of deleteing *.raw files at the end of the simulation even if the LTSPICE executable is still active. Here, if requested, *.raw files would be deleted after the .meas directives are run.

The same problem exists for "LTC Simulation Queue Manager.exe" and "LTspSimQ.exe".

Has anyone addressed this or know of a solution? Or am I incorrectly using this tool or missing something?

Regards,

Dean Wilson

In message <CANZ6rKyEwfYVCbrESnaTSuQVpk9_uNbQTtxFZUHKvs9uE-sxfQ@...>, dated Mon, 15 Apr 2013, DEVISREE bala <baladevisree2@...> writes:

hi i am designing an op amp,but i dont know how two simulate circuit.pls reply me

You have to put some effort into helping yourself. First, explore the tutorial and example files available on the list's web site. There are also links there to tutorial web sites and Spice manuals free to download.

When you have a more specific question about simulation, there will be a lot of help available on this mailing list.
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
They took me to a specialist burns unit - and made me learn 'To a haggis'.

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

hi i am designing an op amp,but i dont know how two simulate circuit.pls
reply me

In message <736066489.391198.1366041523194.JavaMail.root@....
comcast.net>, dated Mon, 15 Apr 2013, Jim Wagner <wagnejam99@...> writes:

Same problem with Safari browser on Mac.

The plot thickens. The chances of getting a response from Yahoo is, I suppose, vanishingly small.
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
They took me to a specialist burns unit - and made me learn 'To a haggis'.

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

In message <kkh7vu+igoh@...>, dated Mon, 15 Apr 2013, sawreyrw <sawreyrw@...> writes:

This is true only at low frequcncies, and that's the reason the OP wants to know the effect as a function of frequency.

Well, it's sufficiently true up to some frequency (depending on the definition of 'sufficiently'), but of course it doesn't apply from DC to light.
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
They took me to a specialist burns unit - and made me learn 'To a haggis'.

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

In message <CALBs-TimcdbfLAxu36m7Ee1HQ-dynXhchgbbKNqC+zGjJWvJWw@...>, dated Mon, 15 Apr 2013, Andy <Andrew.Ingraham@...> writes:

He's talking about R2 variations at high frequencies, getting Bode plots. Under those conditions, the assumption falls through.

Indeed: in that case the gain formula gets more complicated, but the output is still a sine wave unless there is slew-rate limiting (aka 'transient harmonic distortion').

--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
They took me to a specialist burns unit - and made me learn 'To a haggis'.

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

Same problem with Safari browser on Mac.


Jim Wagner
Oregon Research Electronics

--- In LTspice@..., John Woodgate <jmw@...> wrote:

In message
<CALBs-TjHj0Lx41mORJzKDHfd+kPbe+U=GYY+WhLO1MsP+7LKGw@...>,
dated Mon, 15 Apr 2013, Andy <Andrew.Ingraham@...> writes:

That's an interesting hypothesis, but I think it's not true. I think
that varying R2 (while a DC signal is placed at the input to the
op-amp) is very different than simply applying a varying signal to the
amp's input. I suspect that if you try it (with .TRAN analysis) you
would see different results.

Doesn't varying R2 just vary the gain by which the DC input voltage is
multiplied to produce the output? So if R2 varies sinusoidally at
frequency f, the output will be a sine wave at frequency f.

Vout = Vin*R2/R1

If R2 = R*sin(2*pi*f*t), Vout = (Vin/R1)*R*sin(2*pi*f*t)
--

John,

This is true only at low frequcncies, and that's the reason the OP wants to know the effect as a function of frequency. Obviously, he needs to do this in the time domain for each frequency of interest. This type of problem has been discussed in this group relative to switch mode power supplies. In effect, time domain methods are used to get a pseudo frequency domain response.

Rick

Doesn't varying R2 just vary the gain by which the DC input voltage is
multiplied to produce the output? So if R2 varies sinusoidally at
frequency f, the output will be a sine wave at frequency f.

Vout = Vin*R2/R1

Within the range where the op-amp has infinite gain, sure.

At 1 MHz, I doubt it.

He's talking about R2 variations at high frequencies, getting Bode
plots. Under those conditions, the assumption falls through. Think
about what happens at the output node when the op-amp is totally
unresponsive (no current from its output pin, take the op-amp out of
the circuit).

Andy

--- In LTspice@..., Andy <Andrew.Ingraham@...> wrote:

Now coming to the issue in thread, I have this feeling that frequency is
just a frequency for an opamp, Whether it is that of input source or that
of any component variation.

I am not sure what you mean. But an op-amp is no different than other
components. Frequency applies to every thing in the circuit, not just
op-amps.

What I mean here is, in the circuit whether it is 10KHz variation of R2 or that of vin, your opamp always 'thinks' the same- it is working at 10KHz.

This motivates me to put this hypothesis that i can plot the Bode due to
rapid variation of R2 by just assuming R2 to be constant at its maximum
value and sweeping the frequency of input vi (Vi should be changed to
AC source).

That's an interesting hypothesis, but I think it's not true. I think
that varying R2 (while a DC signal is placed at the input to the
op-amp) is very different than simply applying a varying signal to the
amp's input. I suspect that if you try it (with .TRAN analysis) you
would see different results.

Could you kindly show it by a simulation that hypothesis is wrong?

One thing I also just noticed about your earlier circuit, was that you
were varying R2 between 3000 and -1000 ohms. Did you really intend
for R2 to go negative?

Thanks for pointing it out. That was unintentional and my carelessness. Due to this comment( and after changing amplitude of sinusoid) I got it today what Sedra means when he writes that limited bandwidth is linear phenomenon and doesn't cause distortion (while SR does).

Regards,
Andy

In message <CALBs-TjeU10HN8E+Ba97R=LTNiyy-2ar5jyNQunNBcHqRv1Hqw@...>, dated Mon, 15 Apr 2013, Andy <Andrew.Ingraham@...> writes:

Also, given the way Yahoo serves things to users worldwide, sometimes there are differences between what you get and what I get, because we access different Yahoo servers even to access the same file. They don't seem to keep all their servers in sync.

That could explain why some of us now don't see the problem. But I'm not sure that using a non-Microsoft browser fully insulates one from Microsoft 'improvements'.
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
They took me to a specialist burns unit - and made me learn 'To a haggis'.
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

In message <CALBs-TjHj0Lx41mORJzKDHfd+kPbe+U=GYY+WhLO1MsP+7LKGw@...>, dated Mon, 15 Apr 2013, Andy <Andrew.Ingraham@...> writes:

That's an interesting hypothesis, but I think it's not true. I think that varying R2 (while a DC signal is placed at the input to the op-amp) is very different than simply applying a varying signal to the amp's input. I suspect that if you try it (with .TRAN analysis) you would see different results.

Doesn't varying R2 just vary the gain by which the DC input voltage is multiplied to produce the output? So if R2 varies sinusoidally at frequency f, the output will be a sine wave at frequency f.

Vout = Vin*R2/R1

If R2 = R*sin(2*pi*f*t), Vout = (Vin/R1)*R*sin(2*pi*f*t)
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
They took me to a specialist burns unit - and made me learn 'To a haggis'.

John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

Now coming to the issue in thread, I have this feeling that frequency is
just a frequency for an opamp, Whether it is that of input source or that
of any component variation.

I am not sure what you mean. But an op-amp is no different than other
components. Frequency applies to every thing in the circuit, not just
op-amps.

This motivates me to put this hypothesis that i can plot the Bode due to
rapid variation of R2 by just assuming R2 to be constant at its maximum
value and sweeping the frequency of input vi (Vi should be changed to
AC source).

That's an interesting hypothesis, but I think it's not true. I think
that varying R2 (while a DC signal is placed at the input to the
op-amp) is very different than simply applying a varying signal to the
amp's input. I suspect that if you try it (with .TRAN analysis) you
would see different results.

One thing I also just noticed about your earlier circuit, was that you
were varying R2 between 3000 and -1000 ohms. Did you really intend
for R2 to go negative?

Regards,
Andy

It is a pain in the neck having to download it every time (or to fine [OOPS- find]
the copy I downloaded last week), but it does work.

Can you save it to your desktop, to make it easier to find?

Like the question about labeling hundreds of nodes, that doesn't
always work. I already have way too much stuff on my Desktop. Also,
one of the computers is shared and I like to keep my regular files
separate from my wife's if possible so we don't clutter each other's
workspaces.

That and my experience suggest that it's not a Yahoo thing but something
on individual computers, probably a Microsoft 'improvement'.

I personally doubt it's a Microsoft 'improvement'. The computer I
first noticed this on, was not doing automatic Microsoft updates, and
I was not and am not using a Microsoft web browser.

It's been noticed on a variety of web browsers. I think it is odd
that they should all start misbehaving at the same time.

I wondered if maybe Yahoo did this as a security enhancement in
Yahoogroups: disabling the ability to directly load and run
user-uploaded HTML files.

It could even be that Microsoft made an "improvement" in IE to
counteract Yahoo's security enhancement. :-)

Also, given the way Yahoo serves things to users worldwide, sometimes
there are differences between what you get and what I get, because we
access different Yahoo servers even to access the same file. They
don't seem to keep all their servers in sync.

Andy

Hi Andy,
Thanks for your response, but I do understand step vs slope. My question was actually about some difference in the syntax of the statement examples (which I couldn't detect). For some reason I was thinking that some subtle difference was making the first example actually step. But after closer inspection, I see that they both change in slopes, but the chosen values just force the slopes to be short. Sometimes I miss the obvious...

Thanks,
Mike

Hello All,

@ Andy& Jim:Thanks for your input on tmax in .tran analysis. It was really useful and I plan to have a different thread on this soon.

Now coming to the issue in thread, I have this feeling that frequency is just a frequency for an opamp, Whether it is that of input source or that of any component variation. This motivates me to put this hypothesis that i can plot the Bode due to rapid variation of R2 by just assuming R2 to be constant at its maximum value and sweeping the frequency of input vi (Vi should be changed to AC source).
Here is setup files to show this:



In inv_opm_freq_respns.asc I have setup to plot frequency sweep. I select three frequncies: 10KHz, 200KHz, 750KHz. I noticed that at the first two frequencies output is constant and at around 750KHz it rolls down by 3dB.

Now in setup inv_opm_tran.asc, I do a transient analysis. I stepped R2 with above three frequencies and found that as suspected, output have same amplitude at 10KHz and 200KHz,and lower at 750KHz.

As always, I especially seek views of people like Helmut, Andy, Jim, John , analogspiceman,chris to see if there is any fallacy in my understanding.
Conference date has been extended to I have ample time to go deep down the problem.

Thanks.