Cheap, Cross-Platform Electronic Circuit Simulation Software?

dv82 writes "I teach circuits and electronics at the undergraduate level, and have been using the free student demo version of OrCad for schematic capture and simulation because (a) it comes with the textbook and (b) it's powerful enough for the job. Unfortunately OrCad runs only under Windows, and students increasingly are switching to Mac (and some Linux netbooks). Wine and its variants will not run OrCad, and I don't wish to require students to purchase Windows and run with a VM. The only production-quality cross-platform CAD tool I have found so far is McCad, but its demo version is so limited in total allowed nets that it can't even run a basic opamp circuit with a realistic 741 opamp model. gEDA is friendly to everything BUT Windows, and is nowhere near as refined as OrCad. I would like students to be able to run the software on their laptops without a network connection, which eliminates more options. Any suggestions?"

Comments

Cadsoft Eagle

[flyingfsck]

Eagle is pretty good: http://www.cadsoftusa.com/

CAD

[Klivian]

For simulation, you can get Spice versions for all platforms.

For the CAD part, there is the EAGLE Light Edition from CadSoft http://www.cadsoftusa.com/freeware.htm It runs on Linux, Windows and Mac.

Re:CAD

[Anonymous Coward]

State of the FREE circuit simulators is bad on Linux. All serious commercial simulator with exception of PSpice work on Linux. Check HSpice and HSIM from Synopsys, Spectre from Cadence and Eldo from Mentor.

Re:Netbooks?

[Omniscient Lurker]

Legally you'd still have to buy windows to run it in a VM, a professor/teacher can't advocate piracy (well they could but the carious higher ups probably won't like it).

JMCAD

[TrashGod]

You might look at JMCAD. I haven't built it since v0.08.087, but v1.4 is current.

Might not be what you need...

[Anonymous Coward]

This might not be anywhere near what you need, but this application definitely helped out my friend in his intro to electronics class

Falstad Circuit Simulator Applet

Really good on rudimentary stuff, done in Java for cross platform goodness.

Eagle is no simulator

[Anonymous Coward]

Electronics CAD != Circuit Simulation.

Re:Netbooks?

[JesseL]

Whether running Linux or Windows - aren't you going to run into some serious horsepower issues if you try to accommodate students who own netbooks?

I don't see why. Most student level electronics simulation just shouldn't be all that CPU intensive. When I was an EE student 10 years ago, people did just fine with 150MHz machines running SPICE.

LTSpice and SolveElec

[Vario]

LTSpice is free as in beer and works nicely even with more complicated problems. There is only a windows version available, but Linux support with wine should not be a problem. http://www.linear.com/designtools/software/

For simple circuits SolveElec runs on windows and mac, has a very nice user interface and is a good tool for teaching. http://www.physicsbox.com/indexsolveelec2en.html

Re:LTSpice and SolveElec

[Anonymous Coward]

LTSpice[...]Linux support with wine should not be a problem

Actually, since way back when, Mike Engelhardt has taken pains to assure the WINE-compatibility of LTspice. (Notice that the capitalization in the name of that app only applies to Linear Technology's name.)
In an odd irony, in its current incarnation, support for Win9x was dropped in that "native" Windoze app.

...and if the submitter of the question really wants his kids to produce their own PWBs, KiCAD is the universal app (open source).
Cadsoft's EAGLE *used* to be an acceptable cross-platform tool--but not since they got into the DRM business. The EAGLE Virus

gewg_

Paul Falstad's applet

[Dust Puppy]

There is a nice applet at http://www.falstad.com/circuit/ - it might not be sufficiently sophisticated but it does at least handle op-amps.

Not a fan of (P/NG/LT/Berkeley)SPICE

[TerranFury]

I've had to use a handful of circuit simulators, and I've always found SPICE brittle. Perfectly reasonable circuits just refuse to simulate, even when good initial conditions are set. Now it's possible I've been doing something wrong. But on the whole I find SPICE deeply frustrating.

The most robust simulator I've used so far has been a demo version of SiMetrix. HSPICE also does a bang-up job... when it doesn't segfault. Unfortunately, HSPICE is very un-free (and buggy-as-hell), and although SiMetrix does have a demo, it's artificially limited in the size of circuits it can simulate.

Thoughts?

Re:Not a fan of (P/NG/LT/Berkeley)SPICE

[Andrew Sterian]

It's quite likely you've been doing something wrong :-) I was at the same place, getting frustrated because perfectly reasonable circuits refuse to simulate. 99.9% of the time it was my fault, and it was a great learning opportunity. "Reasonable circuits" are not necessarily practical circuits. For example, you can put in an ideal switch into SPICE and cause brittleness, because practical circuit voltages and currents don't change instantaneously like ideal switches do. "But wait!", you say, "Inductor voltages can change instantaneously! That's what it says in my textbook!". No, they can't :-) There's a reason SPICE lets you specify an inductor's parasitic parallel capacitance.

Also, another source of brittleness/bugginess is poor third-party circuit models. I've downloaded some MOSFET models that just plain stunk.

BTW, LTSpice is my favorite simulator, hands down.

LTspice & TINA-spice

[The Lerneaen Hydra]

I've actually been in the same situation myself, two free (as in beer) SPICE derivatives I've found to work well are LTspice and TINA-spice (from linear and Texas Instruments respectively). They are windows binaries but function very well in WINE (in fact the developer(s) for LTspice have designed it to function as well as possible with WINE).

I've mostly used LTspice and it works very well and has a low learning threshold. Of course you can insert spice directives in the schematic to do more advanced functions like basic parameter sweeps as well as monte-carlo simulations and so on and so forth. Check out LTspice's yahoo group for a bunch of documentation.

As far as other recommendations for eagle go I doubt that's what you're looking for as eagle is solely for schematic capture and pcb design, there are no simulation capabilities in it.

Re:spice

[mkiwi]

I'm not sure why this is modded informative.

SPICE is the software that does the simulation- it is not a front-end anywhere near as good as OrCad. That's like telling someone who wants to write a formal letter to use vi (or emacs). In fact, OrCad does its simulation through SPICE.

IIEE who uses a Mac, and I have looked into this. I have not found anything usable across all platforms, which is a real pain in the butt. As the OP already knows, PSPICE is owned by Cadence so the copyrights and patents for the software are locked up in that. As a result, there really aren't any viable open source alternatives.

The only thing I could think of would be to do something with LabView but that opens up a whole other can of worms in terms of teaching students how to work.

My suggestion is to get your ECpE department to subsidize VMWare or Parallels for students so that they can run PSPICE in OrCad. The world is just kinda crappy that way.

Re:Partner with IT dept and get it hosted via RDP

[kelnos]

Maybe, but the article summary specifically says the guy is looking for a solution that doesn't require a network connection.

Logic Works

[Anonymous Coward]

http://www.logicworks5.com/

Only for windows, but I have made it run in wine with no problems. Pretty powerful, you can simulate a full datapath.

Re:spice

[jank1887]

There are a number of SPICE frontends. Right now I'm using the free LTSpice from Linear Technology. It's a professional quality code that the company releases for free since their main product line is actualy electronic components. The software comes with a full library of LT components of course. BUT, it's windows only. There's a Yahoo user group that may be able to answer questions about how well it runs under VMWare or Parallels, It supposedly runs well under Wine. (Winehq.org says "Works well with wine"). So that could take care of Linux and Windows users, but no idea with Mac. I know Mac users are whiny enough, but don't they have a Wine equivalent yet?

Re:spice

[willy_me]

VMWare or Parallels

Or you could try VirtualBox. I have tried all three and actually prefer VirtualBox even though it is free. On that note, many post-secondary schools have access to free Microsoft software. I know I can download just about anything for free via an MSDN portal on my university webpage - you just have to be registered in computer science.

In order to keep things easy for the students (they should be learning concepts and not software) just pick the best software for the job. Should it require Windows, so be it. Those who run other operating systems can work around it. And this is from a guy who hates Windows...

How long is the class?

[hairyfeet]

I ask this because IIRC you can get 90 day eval versions of Windows for free. They also have a 180 day eval version of Win2K3 server, which will run just about anything the desktop runs. There are even plenty of places around the net that will show you how to turn 2K3 server into Workstation, but for a single class this would probably be overkill.

So why don't you try contacting Microsoft? Since you are teaching a class I wouldn't be surprised if they'd be willing to send you the eval discs for Vista or 2K8 server. Or you could just go here and get the 180 day 2K3 straight from MSFT. So unless your class lasts longer than 6 months there really isn't any reason why they just can't run the software on 2K3 in a VM. With 2K3 they can easily turn off the unneeded server roles and have it run decent on pretty much anything. IMHO this would be the cheapest (free) and quickest way to fix your problem without having to learn a new software.

Re:simple solution

[KillerBob]

He's not exactly wrong, he's just deliberately misinterpreting the law to further his own agenda.

In this case, he's deliberately ignoring the part that says that such circumvention is legitimate for classroom purposes iff it's no longer readily available to acquire through legitimate channels, or only a small exerpt is actually required. In other words, you can photocopy a page from a textbook to use as a handout as an alternative to students forking over $150 for just that one page, or you can provide photocopies of books that are no longer in print, but you cannot hand out copies of software that people are still selling.

Multisim

[DCBoland]

I've used the Multisim/Electronics Workbench package under WINE before with no problems. I've seen it used in labs for teaching students, it should do the job just fine.