Author Topic: Free circuit simulator ?  (Read 11184 times)

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Offline lordvader88Topic starter

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Free circuit simulator ?
« on: March 30, 2019, 01:20:59 pm »
I'm just doing hobby stuff, and I lost the older, simple nice looking sim I had, and LTspice is way over the top for now.

I hate online sim's in priniclpe, so what free programs are easy/look good/have common transistors, opamps already included ?

I tried 2-3 freeware sim's over this past year, and I don't remember their names, and I didn't like them. If I place a BJT and resistors, and even a GND, it should work without having to read a damn manual do run the sim, not give BS errors.
 
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Offline Cliff Matthews

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Re: Free circuit simulator ?
« Reply #1 on: March 30, 2019, 02:13:11 pm »
Maybe try compressing a favorite LTspice cheat sheet (in a way that works for you)?
Here's one from U of T http://www.eecg.toronto.edu/~ali/spice/LTspice/LTSpiceShortGuide.pdf
Afrotech has a 3 part series too:

 
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Offline soldar

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Re: Free circuit simulator ?
« Reply #2 on: March 30, 2019, 02:55:44 pm »
I agree that LTspice is unintuitive and clumsy.  I will be following this thread.
All my posts are made with 100% recycled electrons and bare traces of grey matter.
 

Offline Wimberleytech

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Re: Free circuit simulator ?
« Reply #3 on: March 30, 2019, 03:00:16 pm »
I'm just doing hobby stuff, and I lost the older, simple nice looking sim I had, and LTspice is way over the top for now.

I hate online sim's in priniclpe, so what free programs are easy/look good/have common transistors, opamps already included ?

I tried 2-3 freeware sim's over this past year, and I don't remember their names, and I didn't like them. If I place a BJT and resistors, and even a GND, it should work without having to read a damn manual do run the sim, not give BS errors.

What was the name of the simulator you had???

I suggest that you put the effort into LTSpice.  If for no other reason than you have THIS FORUM to help you.  Seems like everyone here uses LTSpice and EVERYONE wants to help.  You have a problem??...upload your .asc file, and we are here to help.
 
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Offline Cliff Matthews

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Re: Free circuit simulator ?
« Reply #4 on: March 30, 2019, 03:05:42 pm »
I'm just doing hobby stuff, and I lost the older, simple nice looking sim I had, and LTspice is way over the top for now.

I hate online sim's in priniclpe, so what free programs are easy/look good/have common transistors, opamps already included ?

I tried 2-3 freeware sim's over this past year, and I don't remember their names, and I didn't like them. If I place a BJT and resistors, and even a GND, it should work without having to read a damn manual do run the sim, not give BS errors.
If for no other reason than you have THIS FORUM to help you.  Seems like everyone here uses LTSpice and EVERYONE wants to help.  You have a problem??...upload your .asc file, and we are here to help.

That's why I love this place!  :-+  Nothing else like it on the planet I figure.
 
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Offline Gyro

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Re: Free circuit simulator ?
« Reply #5 on: March 30, 2019, 04:11:34 pm »
You could try TI's Tina-TI. I haven't compared it for a while but I think it seemed a bit easier.
Best Regards, Chris
 

Offline rstofer

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Re: Free circuit simulator ?
« Reply #6 on: March 30, 2019, 04:34:40 pm »
Like everything else, take small steps.

This is just one of many video tutorials:
https://learn.sparkfun.com/tutorials/getting-started-with-ltspice/all

For better or worse, LTspice is the standard among hobbyists.

There is an LTspice group on Yahoo Groups and a few of the members are true experts with close ties to the author of LTspice.  You can get excellent advise.  There is another group called LTspiceFiles where you can find models and circuits of general interest.
 

Offline jmelson

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Re: Free circuit simulator ?
« Reply #7 on: March 30, 2019, 04:48:23 pm »
I agree that LTspice is unintuitive and clumsy.  I will be following this thread.
But, if you want to design with AD and LT parts, you may be FORCED to, as there may not be generic SPICE models for many of their parts.  I'd MUCH rather use my trust old (and paid for) simulator, but if I can't get device models, I'm stuck.

Jon
 

Offline Nominal Animal

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Re: Free circuit simulator ?
« Reply #8 on: March 30, 2019, 05:10:51 pm »
As I'm very much a beginner hobbyist on the electronics side, I'm using QUCS as a sanity-checker for my designs, using generic components rather than exact ones.  (QUCS-S fork has better spice compatibility.)

You might wish to read the recent Good open source circuit simulation software thread.
 

Offline Wimberleytech

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Re: Free circuit simulator ?
« Reply #9 on: March 30, 2019, 06:22:25 pm »
More random thoughts and pitch for LTSpice.

I ran my first SPICE simulation using SPICE2 via punched cards in 1977.  Somebody at the data center had to load the tape before my program ran.  I was amazed.  Went to work as a chip designer and ran punched card SPICE simulations for several years until we acquired a VAX-750.  ALL of my simulations were netlist based...no GUI...until returning to work after my Ph.D. in 1992 when I started using the Cadence GUI...all GUI SPICE simulations thereafter.

I would have adopted LTSpice sooner if I had realized how to control LTSpice at a deeper level...choosing my desired MOS model and transistor characteristics (W,L, D/S areas, etc.).  Frankly, I have found no limitations.  Recently I was doing some behavioral stuff using controlled sources using table models.

It was this forum that ultimately dragged me into the world of LTSpice and I am glad it did!!!

As others have said...it is clunky.  But not as clunky as a netlist!!!!!

<edit>
I was an early adopter of PSPICE.  Ran simulations on a Compaq (sewing machine) Computer...Circa 1985.
« Last Edit: March 30, 2019, 06:28:04 pm by Wimberleytech »
 

Online Zero999

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Re: Free circuit simulator ?
« Reply #10 on: March 30, 2019, 09:11:53 pm »
I've used LTSpice for around ten years now and only recently had to RTFM. I learned most of it on my own and by opening files created by others, whether it be the examples included or those posted on forums, such as this one.

Lots of people find LTSpice difficult to use because it's different to other Windows applications, but it didn't bother me because I've used lots of GUI software on other platforms than M$: the Acorn Archimedes when I was much younger, then Windows and later Linux. I think having experience with using a variety of user interfaces helps one learn to use programs such as LTSpcie, which differ from the norm.

Another thing which beginners often struggle with is, LTSpice is not a real time simulator. The circuit is designed, the simulation run and the results shown. Many educational simulators aimed at beginners attempt to simulate a circuit in real time which has limitations, mainly that they have to be optimised for speed, over accuracy, as everything needs to happen fast enough to respond to the user's input.
 

Offline Rerouter

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Re: Free circuit simulator ?
« Reply #11 on: March 30, 2019, 09:20:40 pm »
My go to is falstads circuit simulator, not as fully featured as spice, but for testing out concepts, its much faster to play with.

http://www.falstad.com/circuit/circuitjs.html
 
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Offline Cliff Matthews

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Re: Free circuit simulator ?
« Reply #12 on: March 30, 2019, 09:24:38 pm »
Any chance OP is left-handed? Docs show LTspice can move around keys.  http://ltwiki.org/index.php?title=LTspice_Hot_Keys
 

Offline soldar

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Re: Free circuit simulator ?
« Reply #13 on: March 30, 2019, 09:24:56 pm »
Another thing which beginners often struggle with is, LTSpice is not a real time simulator. The circuit is designed, the simulation run and the results shown. Many educational simulators aimed at beginners attempt to simulate a circuit in real time which has limitations, mainly that they have to be optimised for speed, over accuracy, as everything needs to happen fast enough to respond to the user's input.

I have two main complaints. One is that it is not intuitive in finding components or doing actions. I waste a lot of time with this.

And then, once you have drawn the circuit you still have to run it and this is also confusing. You need to set some parameters and then click run and most of the time it goes into a calculating frenzy which goes nowhere and you have to tinker with the run parameters and try again.

Very not intuitive in many ways which makes it very slow.
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Offline Wimberleytech

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Re: Free circuit simulator ?
« Reply #14 on: March 30, 2019, 10:11:40 pm »
Another thing which beginners often struggle with is, LTSpice is not a real time simulator. The circuit is designed, the simulation run and the results shown. Many educational simulators aimed at beginners attempt to simulate a circuit in real time which has limitations, mainly that they have to be optimised for speed, over accuracy, as everything needs to happen fast enough to respond to the user's input.

I have two main complaints. One is that it is not intuitive in finding components or doing actions. I waste a lot of time with this.

And then, once you have drawn the circuit you still have to run it and this is also confusing. You need to set some parameters and then click run and most of the time it goes into a calculating frenzy which goes nowhere and you have to tinker with the run parameters and try again.

Very not intuitive in many ways which makes it very slow.

Then don't use it!  Move along these are not the droids we are looking for.
« Last Edit: March 30, 2019, 10:13:43 pm by Wimberleytech »
 
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Offline StillTrying

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Re: Free circuit simulator ?
« Reply #15 on: March 30, 2019, 10:37:47 pm »
The first thing I do with LT is drag the toolbar from under the menus and drop it on the status bar. Using the icons from there I find it very easy to draw the schematic, I can do most of the drawing and editing without thinking about it so it can't be all that hard. :)
.  That took much longer than I thought it would.
 
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Offline Wimberleytech

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Re: Free circuit simulator ?
« Reply #16 on: March 30, 2019, 11:42:44 pm »
The first thing I do with LT is drag the toolbar from under the menus and drop it on the status bar. Using the icons from there I find it very easy to draw the schematic, I can do most of the drawing and editing without thinking about it so it can't be all that hard. :)

LOL...didn't know you could do that...see...what a versatile program!!  Definitely get your money's worth!!!

For those who do not know, you can tweak the hot keys to your liking...I do.
 

Offline Cliff Matthews

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Re: Free circuit simulator ?
« Reply #17 on: March 31, 2019, 12:03:13 am »
The first thing I do with LT is drag the toolbar from under the menus and drop it on the status bar. Using the icons from there I find it very easy to draw the schematic, I can do most of the drawing and editing without thinking about it so it can't be all that hard. :)

LOL...didn't know you could do that...see...what a versatile program!!  Definitely get your money's worth!!!

For those who do not know, you can tweak the hot keys to your liking...I do.
Ahoy mate, that's what I said in #7..
 

Offline Wimberleytech

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Re: Free circuit simulator ?
« Reply #18 on: March 31, 2019, 12:12:32 am »
The first thing I do with LT is drag the toolbar from under the menus and drop it on the status bar. Using the icons from there I find it very easy to draw the schematic, I can do most of the drawing and editing without thinking about it so it can't be all that hard. :)

LOL...didn't know you could do that...see...what a versatile program!!  Definitely get your money's worth!!!

For those who do not know, you can tweak the hot keys to your liking...I do.
Ahoy mate, that's what I said in #7..

It's not what you said...it is how you said it!  ;)  Nonetheless...methinks we are kindred spirits with miles between us.
 
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Offline StillTrying

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Re: Free circuit simulator ?
« Reply #19 on: March 31, 2019, 12:18:16 am »
Almost everything on the LT schem. and plot including blank space and some icons has a right-click menu, so I don't use the top menu or hotkeys.
.  That took much longer than I thought it would.
 

Offline DimitriP

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Re: Free circuit simulator ?
« Reply #20 on: March 31, 2019, 12:58:18 am »
Quote
Very not intuitive in many ways which makes it very slow.

There is no "not intuitive" software. Only people lacking intiution.

But it's easier to blame the software.


   If three 100  Ohm resistors are connected in parallel, and in series with a 200 Ohm resistor, how many resistors do you have? 
 
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Offline Ian.M

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Re: Free circuit simulator ?
« Reply #21 on: March 31, 2019, 02:25:50 am »
For various reasons I still use LTspice IV which has a less rich U.I than the current  LTspice XVII. 

LTspice is a lot easier to 'drive' if you use a five button mouse + a utility like X-Mouse Button Control that lets you map macros to mouse buttons on a per application basis.  You could also use a gaming mouse with its OEM button utility.

For LTspice, I use the side buttons (normally browser navigate Forward/Back) to make must commonly used commands directly accessable without needing to click the toolbar or touch the keyboard.   One of the side buttons acts as a modifier key to access extra macros on all the other buttons, and the other side button starts a 'Drag' at the cursor position by sending  {F8}{Enter} keystrokes on buttondown.

With the modifier button held, the 'Drag' button becomes 'Move' ({F7}{Enter}), Left becomes 'Wires' mode ({F3}), Right becomes the 'Select Component' dialog ({F2}}.  Finally, wheel up becomes rotate clockwise ({Ctrl}r), wheel down becomes rotate anticlockwise ({Ctrl}r{Ctrl}r{Ctrl}r) and the wheel button becomes 'Mirror' ({Ctrl}e), all of which are valid for the currently active move, drag or component placement.   Its also worth noting that a plain right-click aborts move/drag/place operations.

That leaves 'Duplicate' aka 'Copy' and 'Delete' unmapped, but as they can be quite destructive if inadvertently selected, I prefer to use them from the keyboard or toolbar.

On the speed side of things - if it bogs down when you click 'Run' it usually means either you've done something dumb like forgetting to ground an appropriate node, (which doesn't always trigger an error message, as some components provide very high impedance paths to an implicit ground), or its trying to find an initial stable state for a circuit that may not even have a steady state, or you're trying to do *FAR* too much* on your sim.

Most new sims will start and run with a .tran 1m startup sim command (or instead of 1m, another duration depending on the timescale you are interested in) as initial operating point issues go away when the circuit  starts from 'Switched off'!  Other causes of stalling normally indicate a non-physically-realisable circuit, e.g. expecting a diode to instantly block when a current reverses, without allowing any stray or junction capacitance that will limit the dV/dt across it or charging a zero ESR ideal capacitor from a zero output resistance ideal voltage source.

* I am frequently guilty of this - I tend to do stuff like fully model obsolete mixed signal ICs ( https://www.eevblog.com/forum/projects/ltspice-simulation-madness-xr-2240ua2240lm2240-programmable-counter-timer/ ), Philips PSUs ( https://www.eevblog.com/forum/projects/how-do-make-a-current-limiting-knob-using-lm723-for-linear-reg-power-supplies/msg1212923/#msg1212923 ) or construct complicated sims to generate realistic test signals for anyone who has a design problem I find interesting . . . .
« Last Edit: March 31, 2019, 02:54:45 am by Ian.M »
 

Offline Mattjd

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Re: Free circuit simulator ?
« Reply #22 on: March 31, 2019, 03:51:28 am »
Personally, I like Cadence Orcad. I currently use Orcad 17.2 and it works nicely.

There's a lot too it so i can be confusing, but its very powerful. I would love to buy a full blown version of cadence virtuoso but I'll settle for Cadence Orcad. I've gotten to use both through university. Steep learning curve but very rewarding once you do.

Please done use TINA.
 

Online Zero999

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Re: Free circuit simulator ?
« Reply #23 on: March 31, 2019, 08:19:15 am »
Another thing which beginners often struggle with is, LTSpice is not a real time simulator. The circuit is designed, the simulation run and the results shown. Many educational simulators aimed at beginners attempt to simulate a circuit in real time which has limitations, mainly that they have to be optimised for speed, over accuracy, as everything needs to happen fast enough to respond to the user's input.

I have two main complaints. One is that it is not intuitive in finding components or doing actions. I waste a lot of time with this.

And then, once you have drawn the circuit you still have to run it and this is also confusing. You need to set some parameters and then click run and most of the time it goes into a calculating frenzy which goes nowhere and you have to tinker with the run parameters and try again.

Very not intuitive in many ways which makes it very slow.
The commonly used passive components are on the toolbar and other components can be found by clicking on the AND gate symbol. A lot of time can be saved by using the copy/duplicate command, which needs to be activated before clicking/selecting the items which need to be replicated.

Regarding the simulation, you need to know a bit about how SPICE works to make full use of it. There are several different modes, depending on what you want to do. The results make more sense if you label important nets, using the icon next to the ground symbol, on the toolbar.
 

Offline kripton2035

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Re: Free circuit simulator ?
« Reply #24 on: March 31, 2019, 08:31:02 am »
I bought icircuit some times ago for this purpose: quickly check simple circuits, and I LOVE it.
for some $10 it's really worth it.
exists on win,mac,ios and windows phone.
http://icircuitapp.com/


edit: it's even $5 for windows ...
« Last Edit: March 31, 2019, 08:37:14 am by kripton2035 »
 


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