Author Topic: Ltspice is a big dissapointment !  (Read 5078 times)

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Online eTobeyTopic starter

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Ltspice is a big dissapointment !
« on: March 16, 2023, 11:19:43 am »
Hi,

i wonder why everyone is using (it seems) ltspice. Its like working with a software from 199X, and i dont talk about the looks of it. Hotkeys that other programs have, ltspice does not use like undo for example.

Simulating a button with a relais(?) and a voltage source? It also looks pretty ugly, as the switch does have its "+" on the bottom...
And on top of that, it doesnt even work (cant find the model).

Also a cant probe a node that i have named "base"???

Seriously???

With those limitations i tend to stick with falstad and then test my own circuits.

What about QUCS?? Is it better with this?
« Last Edit: March 23, 2023, 04:26:05 pm by eTobey »
 

Online JohanH

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Re: Ltspice is a big dissapointment !
« Reply #1 on: March 16, 2023, 11:54:38 am »
Keep in mind SPICE was developed in 1970's. There are not many different good free simulators out there and Ltspice isn't even open source (even though popular). Qucs and ngspice are better in this regard. It's still almost necessary to know the spice syntax. I haven't really worked with the GUI tools, but doesn't feel like they are much better than 20 years ago.
 
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Offline RoGeorge

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Re: Ltspice is a big dissapointment !
« Reply #2 on: March 16, 2023, 11:55:21 am »
Disappointment is nothing but wrong expectations.  ;D
LTspice is a great tool once you'll get accustomed to it.

If you think LTspice GUI is bad, just try QUCS.
That will make LTspice seem gorgeous.  :)
« Last Edit: March 16, 2023, 12:36:26 pm by RoGeorge »
 
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Online iMo

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Re: Ltspice is a big dissapointment !
« Reply #3 on: March 16, 2023, 12:06:01 pm »
F9 is undo. There are dozens of various switches, you have to download and install libraries.
https://groups.io/g/LTspice
LTSpice is not an interactive toy, you have to program the behavior of the switches.
When you name a wire "base" you can easily probe it..
I never had a problem with copy/paste something off the results windows in LTSpice..
Get a little bit familiar with the LTSpice, it is a great tool..
« Last Edit: March 16, 2023, 12:10:56 pm by imo »
 
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Offline RoGeorge

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Re: Ltspice is a big dissapointment !
« Reply #4 on: March 16, 2023, 12:17:53 pm »
Also, the keys can be reassigned from the LTspice menu Tools -> Control Panel -> Drafting Options -> Hot Keys

Click on each tab and each key you want to change, even if that may seem grayed out.
I use CTRL+Z for undo, and redefined almost all the other shortcut keys and colors, too.

Offline vk6zgo

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Re: Ltspice is a big dissapointment !
« Reply #5 on: March 16, 2023, 12:58:30 pm »
What ruined it for me was when I realised it liked to mark ac generators with "+ & -" like DC ones.

This was followed up by a plethora of beginners complaining because their Op Amp circuits worked perfectly in LT Spice, & became oscillators when built in real life.
I'm too old & cranky to have patience with dysfunctional things like that.
 

Online eTobeyTopic starter

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Re: Ltspice is a big dissapointment !
« Reply #6 on: March 16, 2023, 01:07:16 pm »
Why are there all kinds of modern IC´s but not a bloody simple switch, that has been around since electricity was first discovered???
They copying issue was not an issues, since my VM did not copy the clipboard contents  :o.

I know i have to progam some things. That stupid switch does work somehow, it just wont turn off  >:(.

I can now probe the base of may npn... i dont know why...

Another thing is: using M and m (with values) for the same thing.... so annoying... thankfully it isnt used often, but could ruin your day.

Offline langwadt

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Re: Ltspice is a big dissapointment !
« Reply #7 on: March 16, 2023, 01:12:18 pm »
What ruined it for me was when I realised it liked to mark ac generators with "+ & -" like DC ones.

nothing wrong with +/-, how else would you identify the phase ?

This was followed up by a plethora of beginners complaining because their Op Amp circuits worked perfectly in LT Spice, & became oscillators when built in real life.
I'm too old & cranky to have patience with dysfunctional things like that.

if you don't know what you are doing no tool is going to help ...

 

Offline langwadt

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Re: Ltspice is a big dissapointment !
« Reply #8 on: March 16, 2023, 01:14:54 pm »
Why are there all kinds of modern IC´s but not a bloody simple switch, that has been around since electricity was first discovered???
They copying issue was not an issues, since my VM did not copy the clipboard contents  :o.

I know i have to progam some things. That stupid switch does work somehow, it just wont turn off  >:(.

I can now probe the base of may npn... i dont know why...

Another thing is: using M and m (with values) for the same thing.... so annoying... thankfully it isnt used often, but could ruin your day.

you have to define how you switch works

https://www.analog.com/en/technical-articles/ltspiceiv-voltage-controlled-switches.html

 

Online iMo

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Re: Ltspice is a big dissapointment !
« Reply #9 on: March 16, 2023, 01:17:25 pm »
Do spend a week with basic stuff and you will know more about it.
Mega is "Meg" in LTSpice, milli is "m" in the LTSpice.
You need the model for the switch.
Do not complain - do learn something instead..
 

Offline vk6zgo

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Re: Ltspice is a big dissapointment !
« Reply #10 on: March 16, 2023, 01:53:09 pm »
What ruined it for me was when I realised it liked to mark ac generators with "+ & -" like DC ones.

nothing wrong with +/-, how else would you identify the phase ?
It is a single phase ac signal---in conventional equivalent circuits the only marking on the ac generator is a sine wave symbol.
 
Quote
This was followed up by a plethora of beginners complaining because their Op Amp circuits worked perfectly in LT Spice, & became oscillators when built in real life.
I'm too old & cranky to have patience with dysfunctional things like that.

if you don't know what you are doing no tool is going to help ...

If you mean the beginners & their attempts to produce workable circuitry, I concur, but if it is a "dig" at me, I do know, from practical experience what can happen with a conventional Op Amp circuit if it drives a reactive load.
The normal negative feedback used in such circuits can become positive feedback at a particular frequency, causing oscillation.

If a simulator does not allow for real world characteristics of standard circuits, it is incomplete.
 

Offline nctnico

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Re: Ltspice is a big dissapointment !
« Reply #11 on: March 16, 2023, 02:16:34 pm »
i wonder why everyone is using (it seems) ltspice. Its like working with a software from 199X, and i dont talk about the looks of it. Hotkeys that other programs have, ltspice does not use like undo for example. Or copying text from the result window does not work at all!
You could try Microcap 12 which is also free. It's user interface isn't the best either but IMHO much better compared to LTspice.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Online eTobeyTopic starter

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Re: Ltspice is a big dissapointment !
« Reply #12 on: March 16, 2023, 03:42:24 pm »
I did not know, that i would need a masters degree, to simulate a quite simple circuit...

With the graph... i thought there was no use with scrollwheel, until i figured it out. BUT it is so bad, that it is useless, because it scolls only in tiny steps, and i havent found  a setting.

I would like to use google, but it has become as difficult to use as ltspice. I might just use it, when falstad fails.

Offline TimFox

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Re: Ltspice is a big dissapointment !
« Reply #13 on: March 16, 2023, 03:55:07 pm »
What ruined it for me was when I realised it liked to mark ac generators with "+ & -" like DC ones.

nothing wrong with +/-, how else would you identify the phase ?
It is a single phase ac signal---in conventional equivalent circuits the only marking on the ac generator is a sine wave symbol.
 
Quote
This was followed up by a plethora of beginners complaining because their Op Amp circuits worked perfectly in LT Spice, & became oscillators when built in real life.
I'm too old & cranky to have patience with dysfunctional things like that.

if you don't know what you are doing no tool is going to help ...

If you mean the beginners & their attempts to produce workable circuitry, I concur, but if it is a "dig" at me, I do know, from practical experience what can happen with a conventional Op Amp circuit if it drives a reactive load.
The normal negative feedback used in such circuits can become positive feedback at a particular frequency, causing oscillation.

If a simulator does not allow for real world characteristics of standard circuits, it is incomplete.

Nonsense:  the + and - terminals on an AC generator, as found in real Spice, are required in order for the phase of the signal at another node to make any sense whatsoever.
Generators and phase-sensitive voltmeters in the real world also need this definition.
Failure of a constructed circuit to agree with the Spice simulation is probably due to an incomplete or inaccurate device model for the op amp (which are actually intricate circuits), not the Spice simulation itself.
 
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Offline langwadt

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Re: Ltspice is a big dissapointment !
« Reply #14 on: March 16, 2023, 04:46:56 pm »
What ruined it for me was when I realised it liked to mark ac generators with "+ & -" like DC ones.

nothing wrong with +/-, how else would you identify the phase ?
It is a single phase ac signal---in conventional equivalent circuits the only marking on the ac generator is a sine wave symbol.

that is incomplete and won't be work if you have more than one

Quote
This was followed up by a plethora of beginners complaining because their Op Amp circuits worked perfectly in LT Spice, & became oscillators when built in real life.
I'm too old & cranky to have patience with dysfunctional things like that.

if you don't know what you are doing no tool is going to help ...

If you mean the beginners & their attempts to produce workable circuitry, I concur, but if it is a "dig" at me, I do know, from practical experience what can happen with a conventional Op Amp circuit if it drives a reactive load.
The normal negative feedback used in such circuits can become positive feedback at a particular frequency, causing oscillation.

If a simulator does not allow for real world characteristics of standard circuits, it is incomplete.

everything is incomplete, what if someone builds the circuit with dodgy fake ebay opamps on a sketchy bread board with long wires and no decoupling?
 

Offline Feynman

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Re: Ltspice is a big dissapointment !
« Reply #15 on: March 16, 2023, 06:07:43 pm »
The user interface sucks for sure. But it never bothered me, really. I just accept it the way it is ;D
 
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Offline TimFox

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Re: Ltspice is a big dissapointment !
« Reply #16 on: March 16, 2023, 06:26:03 pm »
A clarification about the + and - terminals in Spice.
In the actual Spice file, which is line-oriented, there is a well-defined syntax.
For example, an AC generator with 1 V amplitude connected between nodes 10 and 20 is:
VIN    10   20   AC   1.0
where node 10 is the + node and node 20 is the - node in a graphic display of the circuit.
Similarly, a resistor will also have a + node and - node when the first entry starts with "R".
 

Online SiliconWizard

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Re: Ltspice is a big dissapointment !
« Reply #17 on: March 16, 2023, 07:45:40 pm »
Rants are OK. We all rant sometimes. Use whatever tool you are comfortable with.

LTSpice if free and a great simulator actually.
Now its UI sucks a bit, but you get used to it. Most CAD software, even those that try to look "modern", have pretty, uh, "unique" UIs. Just the way it is.

If you can't use LTSpice for simulating a basic circuit, sorry to say this, but the problem is probably not with LTSpice.
Probably millions of people have been able to use LTSpice, I'm sure you will be too. Maybe have a look at the help, and a few tutorials.
 
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Offline LazyJack

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Re: Ltspice is a big dissapointment !
« Reply #18 on: March 23, 2023, 06:37:30 am »
I did not know, that i would need a masters degree, to simulate a quite simple circuit...



Actually, yes. In today's world of people trying to build stuff based on Istructables and fritzing drawings, lot then assume that electronics is simple. It is not. Spice can do more than simulate a led flasher, and in fact it was designed to accurately simulate complex circuits. Than comes with a steep learning curve and the need to know the limitations and requirements of the tool.
I agree, the gui may look old, but since the laws of physics haven't changed since Spice was developed, nobody felt the need to come up with a new version. I used Spice with the text based input and output long ago. Even that was perfectly usable, if one knew how to do that.
 
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Online eTobeyTopic starter

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Re: Ltspice is a big dissapointment !
« Reply #19 on: March 23, 2023, 04:32:43 pm »
I agree, the gui may look old, but since the laws of physics haven't changed since Spice was developed....

 I did not talk about the GUI. Its perfectly fine, to have an ugly GUI if it works. Rotating parts for example is not as intuitive, as i am used to. As said, it feels like 199x experience...

Offline james_s

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Re: Ltspice is a big dissapointment !
« Reply #20 on: March 23, 2023, 05:07:13 pm »
What's wrong with a 1990s experience? 90s software worked just fine, and Spice has been around much longer than that. It's a professional tool designed for people that know what they're doing, most professional tools are a bit clunky and not intuitive to a beginner, that's why toys like the Falstad simulator exist. Don't get me wrong, it's an impressive toy, I've used it myself, but it's really still just a toy. It's very easy to use but not nearly as powerful as Spice.
 

Online eTobeyTopic starter

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Re: Ltspice is a big dissapointment !
« Reply #21 on: March 24, 2023, 09:55:51 pm »
What's wrong with a 1990s experience? 90s software worked just fine...

Yes wooden wheels work fine too. But I would like to have some rubber tube on it...

Offline n4u

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Re: Ltspice is a big dissapointment !
« Reply #22 on: March 24, 2023, 10:12:01 pm »
Dont forget ltspice is a numeric simulator - u need a good model to have proper behaviour. Even on paper when you using ideal or simplified elements you have wrong - non real life results.
You can generate ltspice files by scripts, or use a gui - just need to some practise.
 

Online SiliconWizard

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Re: Ltspice is a big dissapointment !
« Reply #23 on: March 24, 2023, 10:21:13 pm »
I agree, the gui may look old, but since the laws of physics haven't changed since Spice was developed....

 I did not talk about the GUI. Its perfectly fine, to have an ugly GUI if it works. Rotating parts for example is not as intuitive, as i am used to. As said, it feels like 199x experience...

It doesn't. I don't think you get your references right.

While part of the GUI uses basic Windows GUI (menus, toolbars, dialogs), which is fine - unless you prefer this ugly toyish ribbon menu crap, which in itself is not even part of the Windows base controls, I think the problem you (and quite a few others) have is with the schematic editor, which implements a GUI that is not a "90s" GUI, but really more like a DOS-based UI, with heavy use of function keys, no sensible use of right click, the impossiblity of selecting objects just clicking on them, etc.

That part is not at all a "90s" GUI. GUIs of the 90s were perfectly capable of exposing anything we're used to today.
It's more that many CAD tools in general tend to suffer from the same thing, probably mostly because many of the most popular ones have had versions since DOS and have kept some of the UI for legacy reasons. I don't know the full history of LTSpice (just remember that it was initially called SwitcherCAD), but the author probably also had habits dating back to the very old days, and used to other CAD software.

Maybe just all a detail for you, but would explain james' reply.

Generally speaking, again many CAD tools, even recent versions, have weird quirks and UIs that are definitely not following the standard conventions of GUIs.

Regarding LTSpice in particular, a slight overhaul of the schematic editor and the waveform viewer would do the trick. It's not a huge endeavor.
But as with other CAD tools, I guess this has been put to low priority due to the fact that 1/ it's still usable and 2/ there are millions of users used to LTSpice's UI, and changing it would probably cause more friction than it would remove. And yes, that's the case with a lot of other software, and often explains an apparent lag in modernization. Just the way it is. It's very hard, if impossible, to please both your existing user base and new users.

 

Offline james_s

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Re: Ltspice is a big dissapointment !
« Reply #24 on: March 24, 2023, 11:03:35 pm »
Yes wooden wheels work fine too. But I would like to have some rubber tube on it...

What are you talking about? What exactly are 90s UIs missing that modern UIs have other than cosmetic fluff?

The fact that you don't know how to use a professional tool meant for professional engineers doesn't mean there's anything wrong with the tool.
 
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