¿ªÔÆÌåÓý

  1. LTspice
  2. Messages
Expanded Topics Messages Polls
Date
Re: LTspice XVII Co-exist with LTspice IV?

 

Hello alan.revera

You have nothing to learn more (except for added features) to use LTspice XVII.

If you use files created by LTspice XVII with other softwares, be aware that they are now coded? in Unicode UTF-16LE without BOM.

If you want them as you did with LTspice iV you can open files with notepad and save them in format ANSI.

LTXVII 64bits is actually faster.
With an I7 and 8 Mb I believe you will be happy; almost the first month.

Regards
PhB
Re: I'm ready to give up LTC all toghether.

 

> I did see some curvature in the output waveform, near the end of the edge, so it is not a strictly linear ramp, but it's close.? So, the specified Trise or Tfall works for approximately the 0% to 97% or 99% points (on the cases I tried -- it depends on risetime).? But the slope over most of the edge fits as if it were 0% to 100%.

I think that's LTspice's engine doing its best to keep the derivatives smooth. The same is valid for the default (ideal) diode, for example. When run and zoomed in, the sharp knee is not so sharp. If the timestep is decreased, zooming in until only a few points around the knee are visible reveals the same slight smoothing, and it keeps on going. Even A-devices pulses, unaltered, have a tendency to show a slightly non-linear rise from 0 to 1 or vice-versa. It's just a guess, but it seems to go well along Mike's own words.

Vlad
______________________
-- holding, among others:
a universal analog/digital filter, block-level models
for power electronics (and not only), math blocks
with a more stream-lined approach, some digital
ADC, DAC, (synchronous-)counter, JKflop, etc.
Re: DSBSC

Gunoi Nare
 

Thank you Jim.

Just remembered '78 when using a SAR DAC achieve same result. Hmmm... it it a long time.
used it in NDT on Nuke Reactors :)

How will I display such a signal on the simulator ?

G.


From: "Jim Wagner wagnejam99@... [LTspice]"
To: LTspice@...
Sent: Tuesday, August 16, 2016 3:42 AM
Subject: Re: [LTspice] DSBSC

?
Just a multiplier with no offset. One input is carrier, other is 1200Hz sine. You then have your double sideband suppressed carrier signal.

Jim
James Wagner
Oregon Research Electronics



On Aug 15, 2016, at 11:30 PM, gunoiar@... [LTspice] <LTspice@...> wrote:

Here I really got stuck. I need a signal generator in the simulator to create a
Double Side Band Suppressed Carrier Modulated by 1200HZ.

Can any one point me in the right direction?
G.
Re: Calculation of the inductance of the amplitude of the first harmonic voltage and current amplitude

 

Hello Vlad.
I think not the average, and calculate the amplitude of the first harmonic. I made a parallel Fourier analysis. Look at the first harmonic and what I counted. The values are the same, with sufficient accuracy for practical purposes.

Bordodynov.

16.08.2016, 09:38, "Vlad imbvlad@... [LTspice]" <ltspice@...>:

Hello Bordodynov

You are doing an average of the waveform. For simplicity, let's assume V(x) is a 1V sine, just like the reference. Then:

V(sin) = idt{ Vref * V(x) - delay [ Vref * V(x), 1/f ] } * 2 * f

which translates to:

sin(wt)*sin(wt) - delay[ sin(wt)*sin(wt) , 1/f ] = sin(wt)^2 - delay[ sin(wt)^2, 1/f ]
sin(wt)^2 = [1 - cos(2wt) ] / 2

The average of the above is 1/2 and, from the first equation, multiply by 2 => 1, therefore the result is the amplitude for any V(x).

Vlad
______________________
ltspicegoodies.ltwiki.org -- holding, among others:
a universal analog/digital filter, block-level models
for power electronics (and not only), math blocks
with a more stream-lined approach, some digital
ADC, DAC, (synchronous-)counter, JKflop, etc.
Re: Piece-wise voltage signals

 

Hello

> The signal has a ramp up to a maximum voltage for the first section, then after a short delay drops sharply to a low voltage and holds for a short delay, then charges exponentially to a an intermediate voltage and holds for a short delay, then finally drops sharply to the low voltage again. The signal has a relatively long dead time in-between starting and repeating itself

If the second, exponential rise is a simple, or fairly simple exp(), then you can use a single behavioural source with something along these lines:

.func f(x) { limit( x - delay1, Vmin, Vmax ) }
.func g(x) { limit( exp( (x - delay2) / tau), Vmin, Vmax ) }
B out 0 V=f(time)+g(time)

where {delay1} and {delay2} are arbitrary and {tau} is the time constant. Note that limit() is hard limited, so instead you may want to use:

uplim( dnlim( x, min, quadratic_region ), max, quadratic_region )

(see for reference).

Vlad
______________________
-- holding, among others:
a universal analog/digital filter, block-level models
for power electronics (and not only), math blocks
with a more stream-lined approach, some digital
ADC, DAC, (synchronous-)counter, JKflop, etc.
Re: DSBSC

 

¿ªÔÆÌåÓý

Just a multiplier with no offset. One input is carrier, other is 1200Hz sine. You then have your double sideband suppressed carrier signal.

Jim
James Wagner
Oregon Research Electronics



On Aug 15, 2016, at 11:30 PM, gunoiar@... [LTspice] <LTspice@...> wrote:

Here I really got stuck. I need a signal generator in the simulator to create a
Double Side Band Suppressed Carrier Modulated by 1200HZ.

Can any one point me in the right direction?
G.
Re: Calculation of the inductance of the amplitude of the first harmonic voltage and current amplitude

 

Hello Bordodynov

You are doing an average of the waveform. For simplicity, let's assume V(x) is a 1V sine, just like the reference. Then:

V(sin) = idt{ Vref * V(x) - delay [ Vref * V(x), 1/f ] } * 2 * f

which translates to:

sin(wt)*sin(wt) - delay[ sin(wt)*sin(wt) , 1/f ] = sin(wt)^2 - delay[ sin(wt)^2, 1/f ]
sin(wt)^2 = [1 - cos(2wt) ] / 2

The average of the above is 1/2 and, from the first equation, multiply by 2 => 1, therefore the result is the amplitude for any V(x).

Vlad
______________________
-- holding, among others:
a universal analog/digital filter, block-level models
for power electronics (and not only), math blocks
with a more stream-lined approach, some digital
ADC, DAC, (synchronous-)counter, JKflop, etc.
DSBSC

[email protected]
 

Here I really got stuck. I need a signal generator in the simulator to create a
Double Side Band Suppressed Carrier Modulated by 1200HZ.

Can any one point me in the right direction?
G.
Re: Calculation of the inductance of the amplitude of the first harmonic voltage and current amplitude

 

Hello.
I investigated the current transformer ratio as a function of the inductance of the secondary winding. The transformer includes a non-linear core. As a result, the inductance depends on the signal level. And hence the transmission ratio of the current transformer depends on the magnitude of the signal. The question is how to determine the inductance. I came up with four ways.
Question: Which method is most suitable.
See four_ways_to_determine_the_inductance.zip in TEMP folder.

Bordodynov.

15.08.2016, 15:03, "BordodunovAlex@... [LTspice]" <ltspice@...>:

Hello.

See file Meas_Lx.asc in TEMP folder.

It is considered an inductance (large signal), as I have shown in the example? From a plot of inductance on the current amplitude is seen maximum!

Bordodynov.
Re: I'm ready to give up LTC all toghether.

Gunoi Nare
 

"I find that many young engineers have no ability to IMAGINE a circuit."

Well said Jim :)
G.


From: "Jim Thompson ltlist@... [LTspice]"
To: LTspice@...
Sent: Monday, August 15, 2016 11:37 AM
Subject: [LTspice] Re: I'm ready to give up LTC all toghether.

?
At 07:08 AM (-0700) 8/15/2016, davnor49 wrote:

---------- Original Message ----------
>G,
>
>Calm down for five minutes and consider all those who had to design
>circuits without circuit simulators and nice assemblers to write
>machine code for them.
>
>Dave N
---------- End of Original Message ----------

Yep. I amuse myself periodically by remembering that I designed
ASIC's for 18 years before I had my hands on a simulator, and that
was Berkeley Spice 2G6 on a VAX. And there was no schematic
capture... I had to draw schematics on paper, number the nodes, then
type up a netlist :-D

In a way I think that's an advantage... I design circuits in my head,
on paper, and with a calculator, then enter them into a simulator for
verification.

I find that many young engineers have no ability to IMAGINE a circuit.

...Jim Thompson

Web Site:



Re: I'm ready to give up LTC all toghether.

Gunoi Nare
 

Thank you Andy.

I do know these "facts" but simulator programmers have a tendency
to "improve" on the agreed parameters. It is always wise to ask what the programmer thinks in this respect.

G.


From: "Andy ai.egrps@... [LTspice]"
To: [LTspice] group
Sent: Monday, August 15, 2016 3:43 PM
Subject: Re: [LTspice] Re: I'm ready to give up LTC all toghether.

?
John wrote:

? ?"The formal definitions of rise time and fall time relate to 10 % and 90 % of the amplitude, because it's not possible to say precisely when the pulse is no longer 0 % and when it first reaches 100 %."

That is correct for the method to use to measure rise time and fall time in the lab, where real signals are not straight with sharp corners.

But for generating step waveforms in SPICE, the prescribed rise and fall times refer to the 0% and 100% points of the waveform edges.? This is the convention that UC/Berkeley adopted when they created SPICE some 40 years ago, and LTspice conforms to that convention.

It definitely applies to the PULSE voltage and current source waveforms, and it apparently applies here (to the [Digital] library of A-devices) too.? I just tried it with a NAND gate, and that is what I saw.

I did see some curvature in the output waveform, near the end of the edge, so it is not a strictly linear ramp, but it's close.? So, the specified Trise or Tfall works for approximately the 0% to 97% or 99% points (on the cases I tried -- it depends on risetime).? But the slope over most of the edge fits as if it were 0% to 100%.

Regards,
Andy
Re: Visay spice model Bridge rectifier KBU6B

 

Hello,

There are examples with bridge rectifiers (schematic, symbol, models) with a library of models.
Some models in this library file are similar(voltage, current) ?to the asked model.?

??


These bridge rectifiers are suitable for 50Hz/60Hz operation. Don't use them for switching supplies above 1kHz due to their long reverse recovery time. This recovery time is modeled with the parameter TT in in the SPICE-model.

?

Best regards,

Helmut

?
Re: LTspice XVII Co-exist with LTspice IV?

 

? ?" ...it will work with anything denoted with the ".asc prefix" at the end.? Even files that are simple text files.
? ? Instead of displaying a schematic...you will read that text on the schematic screen."

I think that could be confusing.? I don't want people to get the wrong impression.

LTspice XVII did not change the input files.? It still uses the same input and output files as before.

If you have an LTspice schematic that was from LTspice IV, or from LTspice III, or from SwitcherCAD III, they open directly in the newer program (LTspice XVII) and look like they did before, because nothing's changed!

It is just a better version of the old LTspice.? Yes it was a partial re-write of the source code.? But it is not a totally brand new program.

Andy
Re: LTspice XVII Co-exist with LTspice IV?

 

?...it will work with anything denoted with the ".asc prefix" at the end.? Even files that are simple text files.


Instead of displaying a schematic...you will read that text on the schematic screen.


Be sure and set up your laptop properly...IF you can ..use a separate partition for win7 vs. win8 or win10.


Otherwise you will need* to "open all .asc files" with the LTSPICE IV logo/icon under LTSPICEXVIII...and

any files you need to open in LTSPICEIV using "drag and drop" (that IS one easy way to do that one).


Old 32-bit LTSPICEIV copies on old XP machines won't be an issue.? Just use "sneaker-ware" and

save from a USB drive (or old 3 1/2 inch floppies)..to your system.? Not sure you will have a floppy on a

64-bit box...but that is still possible.? I have a old PSPICE copy for DOS I have yet to find a machine for

..but still looking. 16-bit code does work under stuff like FreeDOS..but you have to be careful porting that

back to newer machines.? I am sure the expert around here on the "old stuff" is still John, but if Mike E.

has some old "DOS/Windows horror stories" about FORTRAN77 SPICE?he should post them.


<---works hard for a few good chuckles every now and then.


W. Warren


*[ ..I recommend a good text editor..TextPAD?

??? ?...or related freeware ..and stay away from editing anything

????? ? in Notepad...even the recent version of Notepad ]
Re: LTspice XVII Co-exist with LTspice IV?

 

? ?"Can XVII work with files already created in IV?"

Yes.
?
? ?"Is it an easy transition from IV the XVII without having to learn a lot of things?"

Yes.
Re: Visay spice model Bridge rectifier KBU6B

 

I've uploaded n KBU6J spice model for your use,
Re: LTspice XVII Co-exist with LTspice IV?

 

Thanks Andy,

I just ordered an I7 laptop with Win10. It's a 64bit. Maybe I should go to the XVII. Can XVII work with files already created in IV?

Is it an easy transition from IV the XVII without having to learn a lot of things? I am just barely ok in using IV ( maybe not even barely ok!!).
Re: LTspice XVII Co-exist with LTspice IV?

 

...I think I already documented some of my early experiences with Win10..and dual installations.

I still have my old Win7 files on a separate Win7 partition..and can access them under Win10
or even run them under the old LTSPICEIV program in Win7.

Some of you might be wondering why so many are using WINE here and not just Windows.

Because all that expensive software (well a lot of it anyway) can be duplicated under Linux...and
its "freeware, shareware..user-ware" models.? Take the Eagle CAD program for instance.? It was
never taken to 64-bit..and got grabbed* by the AWR "Microwave Office" people some time back.? It is their
drafting program now...and file convertor. You can still find Eagleware on the web and in some old
Ubuntu installation versions.? It easily will convert various SPICE versions for CAD purposes..or CAE
versions from its CAD format.? I have transliterated some old microwave designs into LTSPICE circuits
using both Eagleware (see:?? and gEDA/ngSPICE )
?
Give Mike E. some credit..at least for the Mac users...they "might be getting an update" good enough
to port to FreeBSD and/or other Linuxes.?

W. Warren

*[

??

?? ? ]

?


?
Re: LTspice XVII Co-exist with LTspice IV?

 

alan.revera?wrote:

? ?"Is VII a lot better? What is the major advantage of VII over IV?"

I'm sure you meant XVII, which is the new version. ?(Mike/LTC skipped a lot of version numbers on this, going straight from 4 to 17, I guess because we are nearing 2017.)

There are not many significant differences to most users between IV and XVII, except for this one: ?XVII supports 64-bit program operation if your operating system supports it.? If you are running a 32-bit version of Windows, as many people do (even though their hardware is 64-bit capable), then you won't get this advantage.? The 64-bit version can run a lot faster.

The 64-bit version probably can also handle larger networks (able to access more memory), but very few people run simulations on networks so massive that they run out of memory on a 32-bit O.S.

Most of the other program differences might be considered "cosmetic", affecting the user interface.? Menus, how window panes work, ability to use dual monitor screens, etc.

(Just my opinion, and yours might differ.)

Regards,
Andy
Re: LTspice XVII Co-exist with LTspice IV?

 

I have a stupid question, I only use IV and not very good at that. It get what I want so far. Is VII a lot better? What is the major advantage of VII over IV?

Thanks
67941 - 67960 of 157895