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Cheap, Cross-Platform Electronic Circuit Simulation Software?

timothy posted more than 5 years ago | from the what-we-all-want-when-we-wake-up-in-the-morning dept.

Software 211

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?"

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spice (0, Redundant)

samriel (1456543) | more than 5 years ago | (#28912409)

spice []

Re:spice (2, Informative)

mkiwi (585287) | more than 5 years ago | (#28912843)

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:spice (2, Informative)

jank1887 (815982) | more than 5 years ago | (#28913173)

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. ( 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 (1)

pushing-robot (1037830) | more than 5 years ago | (#28913519)

I know Mac users are whiny enough, but don't they have a Wine equivalent yet?

Considering WineHQ's tagline is "Run Windows applications on Linux, BSD, Solaris and Mac OS X", I'd have to say yes.

Re:spice (1)

boast (1227952) | more than 5 years ago | (#28913675)

I know Mac users are whiny enough, but don't they have a Wine equivalent yet?

I believe its called wine.

Re:spice (2, Informative)

willy_me (212994) | more than 5 years ago | (#28913283)

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...

Qucs ! (5, Interesting)

Ruie (30480) | more than 5 years ago | (#28913123)

Qucs [] is very capable.

Use Spice (0, Redundant)

sys.stdout.write (1551563) | more than 5 years ago | (#28912441)

Spice []

Is a live DVD OK? (4, Interesting)

Anonymous Coward | more than 5 years ago | (#28912451)

If booting off a live DVD is OK then you may want to look at [] .

Re:Is a live DVD OK? (1)

Blakey Rat (99501) | more than 5 years ago | (#28913153)

Will that boot an Apple computer?

Re:Is a live DVD OK? (0)

Anonymous Coward | more than 5 years ago | (#28913477)

Will that boot an Apple computer?

I've booted booted Linux live CDs on my MacBook, works fine. This was on a white Macbook though, I don't know about the newer hardware.

Re:Is a live DVD OK? (0)

Anonymous Coward | more than 5 years ago | (#28913513)

I believe it's possible to use Fedora to create live media for ppcs, but none are built for the release. So you'd need to have someone with Fedora on a ppc make one. (Running livecd-creator is easy.)
For apple machines that are on x86 hardware, I would expect the prebuilt version to boot.
I haven't personally tried any live cd's on ppc hardware as all I have easy access to is x86.

Cadsoft Eagle (1, Informative)

flyingfsck (986395) | more than 5 years ago | (#28912459)

Eagle is pretty good: []

Eagle is no simulator (3, Informative)

Anonymous Coward | more than 5 years ago | (#28912523)

Electronics CAD != Circuit Simulation.

Re:Eagle is no simulator (0)

Anonymous Coward | more than 5 years ago | (#28912859)

I concur! Someone forgot to screw their head on this morning!

Re:Eagle is no simulator (1)

Mozk (844858) | more than 5 years ago | (#28913889)

No, but you can export and run it through SPICE.

CAD (4, Informative)

Klivian (850755) | more than 5 years ago | (#28912463)

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

For the CAD part, there is the EAGLE Light Edition from CadSoft [] It runs on Linux, Windows and Mac.

Re:CAD (0)

nurb432 (527695) | more than 5 years ago | (#28912653)

KiCAD is even cheaper for the 'real thing' and also cross platform.

I don't know if it integrates with spice or anything for simulations.

Re:CAD (3, Insightful)

Grishnakh (216268) | more than 5 years ago | (#28912823)

I use KiCAD and it works quite well for designing PCBs, though it has some rough edges.

However, the discussion is about circuit simulation in college, which has nothing to do with PCB design. KiCAD doesn't currently integrate with Spice unfortunately, though that would be really nice. I don't actually know of any open-source stuff that does Spice well. The SPICE engines themselves are open-source (such as ng-spice), but they have no front-end at all, so you have to do everything at the command line, which is really rather clunky when you want to, say, look at graphs of simulation results.

When I want to simulate a simple circuit (not often), I start up a Windows computer and run an old version of Pspice (9.something) which is freely downloadable. The state of circuit simulation on Linux is very, very bad right now.

Re:CAD (1)

Andrew Sterian (182) | more than 5 years ago | (#28912947)

LTSpice for simulation, Eagle for schematic/PCB design.

In my experience, any tool that does both simulation and schematics is a) crap, or b) really expensive.

LTSpice is free, well supported and actively developed, high quality, and works well under Wine.

Eagle has native versions for Mac/Linux/Windows, has a great educational site license program (reasonable price, no yearly fees, no license server), does schematics+PCB+autorouting, is well supported with its own newsgroups (which are regularly attended by Eagle representatives), is scriptable, and in general is Not Evil.

I'm a big fan of FOSS but I hate to admit that best-effort programs like gEDA and KiCad just don't match up to Eagle.

Re:CAD (1)

davygrvy (868500) | more than 5 years ago | (#28913377)

LTSpice does work well under WINE. But does that make it OK under mac?

Re:CAD (1)

Mwahaha (824185) | more than 5 years ago | (#28913435)

I've used LTSpice under wine on os x, it works fine.

Re:CAD (0, Offtopic)

rfengineer (927289) | more than 5 years ago | (#28913427)

You should try TOPSPICE by Penzar Development. I've been using it for years and it does both schematic capture as well as simulation. I've compared its results to both HSPICE and Smartspice and have been amazed by the results. It also does binning of BSIM3 models.

Re:CAD (1)

Andrew Sterian (182) | more than 5 years ago | (#28914027)

TOPSPICE is $500!!! And only for Windows.

No thanks.

Re:CAD (1)

epine (68316) | more than 5 years ago | (#28913735)

I had good initial success with ltspice under Wine. Not perfect: some dialog boxes don't focus input fields normally (but if you're persistent, you can get it to work).

No problem with the simulations. The command line simulation is more powerful than I at first suspected. I especially appreciated the ability to do multiple plots in parallel. Some basic logic elements were missing (multiple input muxes, IIRC). So there was a startup curve learning how to make my own.

Once annoyance was the plotting setup. The default background is black, which makes screen plots great, but sucks for printed output. You can change the background to white (you also have to make all the colours darker for contrast), then it works fine for printing, but your monitor display is nowhere near as good, and I never found a way to automate the switch. It needs a way to set up the monitor and printer palettes independently.

There is an RLGC simulator for coaxial transmission lines, but it's not fully general. According to my notes: "At least two of RLGC must be non-zero. If G is non-zero, L and C must be zero." I understand there is a way to transform coaxial parameters so you don't need G non-zero, but I haven't yet learned how to do this, so this was a bit annoying.

At once point an obscure error message from ltspice exactly matched the string in source code I found online for Spice 3f4. I believe the underlying simulation code is forked largely unchanged from 3f4.

I've done a lot of embedded programming, mostly in C/restricted C++. I often contribute to the schematic design at a block level, or for a key circuit element critical to the technology, but I'm far from an everyday EE guy. So you can either conclude that ltspice was easily adopted by a non-specialist (well, an elite non-specialist) or, if you have less success than I did, you can conclude that I just didn't push it very hard.

Re:CAD (1)

Grishnakh (216268) | more than 5 years ago | (#28913999)

I'm a big fan of FOSS but I hate to admit that best-effort programs like gEDA and KiCad just don't match up to Eagle.

I'm sorry, I completely disagree.

I've used both Eagle and KiCad, as well as PADS. Eagle has a funky interface (but then again, most EDA programs seem to have funky UIs), but it works well. KiCad has slightly funky interface, though I actually found it a little easier than Eagle. But unlike Eagle, KiCad is free. Eagle costs a LOT of money: I'm pretty sure the cheapest license is $1500. There are two cheaper options, 1) a free trial version which is extremely limited in board space and number of components, and 2) an educational license as you mention hich again is extremely limited in board space. If you're going to do any serious PCB design, Eagle simply doesn't cut it unless you're ready to shell out well over a grand. KiCad can do everything Eagle does, though its libraries aren't as complete (no big deal, it's not that hard to draw your own for things which are missing), and produces professional results. I use it regularly to have PCBs professionally manufactured by various board-houses.

As far as Spice, though, you're right. I don't know of anything in the FOSS realm that's really even usable. There's ng-spice, which has no GUI whatsoever, so it's a real PITA if you just want to draw up a schematic real fast and look at some simulation results.

Re:CAD (1)

Andrew Sterian (182) | more than 5 years ago | (#28914063)

I will have to look at KiCad again (wasn't impressed last time) but I disagree with the Eagle analysis. The freeware license allows for 2-layer 4"x3.2" boards which is definitely enough for a lot of projects.

Even the completely full version for commercial use with no layer or size limitations is $1500 for schematic+PCB+autorouter. That's not the cheapest license, that's the most expensive one!

My university has the completely unlimited professional version site license -- it is NOT limited in board space or layers. And it was at a fair one-time no-yearly-fees no-dongles no-license-server price.

And I forgot to mention that Eagle doesn't screw you over with upgrade costs. When upgrading from version 4 to version 5 (which did include some major new features), the upgrade cost was very reasonable.

Netbooks? (0)

93 Escort Wagon (326346) | more than 5 years ago | (#28912465)

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?

Also, don't forget that Macs can run Windows inside of a VM perfectly well, and Sun's VirtualBox is still free; plus VMware and Parallels offer significant student discounts.

Re:Netbooks? (0)

Anonymous Coward | more than 5 years ago | (#28912487)

RTFS much?

I don't wish to require students to purchase Windows and run with a VM.

Re:Netbooks? (1)

XcepticZP (1331217) | more than 5 years ago | (#28912617)

Lots of universities have license deals with Microsoft. I know at my particular university, one in Africa no less, gives Windows XP out to any student that asks. Same goes for Office 2007, student edition or something. This is what you pay a university for. To not only teach you, but to provide you with the _tools_ to learn.

Re:Netbooks? (0, Flamebait)

Anonymous Coward | more than 5 years ago | (#28912673)

I'm pretty sure that's only true in Africa because of Microsoft's philanthropy. In American universities you're SOL on that front.

Re:Netbooks? (0)

Anonymous Coward | more than 5 years ago | (#28912713)

Windows XP, and Vista, cost me $5 from the univ bookstore. It was the cost to press the disc. I could download the ISO from an internal repo within the univ for free.

Indiana University.

Re:Netbooks? (0)

Anonymous Coward | more than 5 years ago | (#28912807)

Umass lowell is part of the msdn academic alliance ( [] ). Students have access to more or less any msft software, including OSes. all they have to do is talk to the CS department. So no, you're not SOL in America, you're just uninformed :P

Re:Netbooks? (-1, Troll)

Anonymous Coward | more than 5 years ago | (#28912835)

Sorry, I guess I meant "good American schools".

Re:Netbooks? (0)

Anonymous Coward | more than 5 years ago | (#28913061)

keep telling yourself you have to pay $40k+/year for a "good" school.

I want to Lowell, got a job at Raytheon soon after I graduated.

Re:Netbooks? (0)

Anonymous Coward | more than 5 years ago | (#28913615)

I want to Lowell


Re:Netbooks? (2, Informative)

Omniscient Lurker (1504701) | more than 5 years ago | (#28912497)

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).

Re:Netbooks? (1)

maharb (1534501) | more than 5 years ago | (#28913499)

Hear of MSDN(AA)? Any decent school probably has access to this stuff.

Re:Netbooks? (5, Informative)

JesseL (107722) | more than 5 years ago | (#28912537)

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.

Re:Netbooks? (0)

Anonymous Coward | more than 5 years ago | (#28912603)

Funny, I was going to say the same thing. Mod parent up

simple solution (0)

DragonTHC (208439) | more than 5 years ago | (#28912475)

pirate McCad.

the DMCA requires provisions for circumventing copyright for the purposes of classroom instruction.

It's not infringement if you're using it in the classroom. that's the law plain and simple.

Re:simple solution (3, Insightful)

notreez (1093359) | more than 5 years ago | (#28912515)

The law is never plain and simple.

Re:simple solution (0)

Anonymous Coward | more than 5 years ago | (#28912797)

Unfortunately, it's not that simple.

The DMCA has an exception to its prohibition circumventing DRM for classroom use, among other things, but that doesn't make all classroom use noninfringing. That's subject to the same determination of "fair use" as it was pre-DMCA.

Re:simple solution (1)

ThreeE (786934) | more than 5 years ago | (#28912815)


Re:simple solution (1)

Moridineas (213502) | more than 5 years ago | (#28912967)

It's not infringement if you're using it in the classroom. that's the law plain and simple.

So why does anybody buy textbooks if LEGALLY you can just copy the entire book if it's to be used in a classroom.

In other words, you're wrong.

Re:simple solution (3, Informative)

KillerBob (217953) | more than 5 years ago | (#28913705)

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.

Anonymous Coward (0, Redundant)

Anonymous Coward | more than 5 years ago | (#28912479)

try ltspice
it's 100% professional, unlimited and free
though not open-source.
It runs perfect in Linux under wine

Mod this man up ... (1)

Pinky's Brain (1158667) | more than 5 years ago | (#28912679)

LTspice looks very cool.

Partner with IT dept and get it hosted via RDP (4, Interesting)

attemptedgoalie (634133) | more than 5 years ago | (#28912503)

We had finance apps that students had to use in their coursework. Trying to get them to work on a Win/Linux/Mac system would have been painful and time consuming.

So we created a terminal server environment that let anybody RDP in to use the course apps. That way nobody had to pay for a real version, we paid for the terminal license.

That might work well for you rather than finding an app to support in 3 environments.

Good luck!

Re:Partner with IT dept and get it hosted via RDP (2, Informative)

kelnos (564113) | more than 5 years ago | (#28913039)

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

Since when does literacy count for anything? (2, Funny)

attemptedgoalie (634133) | more than 5 years ago | (#28913055)

I *totally* missed that.

I'll go sit in the corner.

JMCAD (2, Informative)

TrashGod (752833) | more than 5 years ago | (#28912505)

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... (2, Informative)

Anonymous Coward | more than 5 years ago | (#28912511)

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.

LTSpice and SolveElec (4, Informative)

Vario (120611) | more than 5 years ago | (#28912545)

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. []

For simple circuits SolveElec runs on windows and mac, has a very nice user interface and is a good tool for teaching. []

Re:LTSpice and SolveElec (1)

Man On Pink Corner (1089867) | more than 5 years ago | (#28912563)

Seconded, it's ridiculous to even consider any other free SPICEs than LTSpice.

Re:LTSpice and SolveElec (1)

locketine (1101453) | more than 5 years ago | (#28912671)

I installed LTSpice with a stock install of wine and it works perfectly. It also supports all the third party spice files manufacturers put out so it's very adaptable like normal spice but easier to use and free.

Re:LTSpice and SolveElec (2, Informative)

Anonymous Coward | more than 5 years ago | (#28913455)

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 []


Re:LTSpice and SolveElec (0)

Anonymous Coward | more than 5 years ago | (#28914019)

Consider it thirded. The other option is TI's free version of TINA, but LTSpice is way better.
(BTW, it sounds like OrCAD is overkill for your class, this is not what you need).

DigSim (0)

Anonymous Coward | more than 5 years ago | (#28912549)

A java applet, now in public domain. That's what we used in our school.

DesignWorks (1)

apuku (576996) | more than 5 years ago | (#28912581)

Professionally, I use Capilano's DesignWorks schematic capture on a Mac (they also support Windows). They have demos and some educational deals . (I use MacSpice for analog simulation and Osmond for PCB layout.) HTH.

School Computer Labs (1)

salted (1390595) | more than 5 years ago | (#28912613)

Isn't this the reason we have computer labs at schools? So what if they can't work on their own computer. P

Re:School Computer Labs (2, Interesting)

Andrew Sterian (182) | more than 5 years ago | (#28912971)

It's the changing college demographic. First, more non-traditional students that want to be able to work at home, at "work", on their own time, etc.

Second, more demanding traditional students that expect colleges to come with more amenities like better dorm rooms than what used to be the norm, private bathrooms, etc. The ability to work in the dorm room or "plug in" wirelessly anywhere on campus and do their homework is becoming an expectation.

We have computer-aided teaching studios now with no computers in them. Doesn't make sense when every student has a laptop. Soon we will not need any computer labs.

c01m (-1, Redundant)

Anonymous Coward | more than 5 years ago | (#28912629)

all partIes it's Other members in

Paul Falstad's applet (2, Informative)

Dust Puppy (63916) | more than 5 years ago | (#28912631)

There is a nice applet at [] - it might not be sufficiently sophisticated but it does at least handle op-amps.

Not a fan of (P/NG/LT/Berkeley)SPICE (4, Informative)

TerranFury (726743) | more than 5 years ago | (#28912635)

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.


Re:Not a fan of (P/NG/LT/Berkeley)SPICE (1)

oldhack (1037484) | more than 5 years ago | (#28912945)

Yeah, I have a thought. If you weren't such a cheapskate and bothered to get the support package "Pepto Bismal" you wouldn't have had such trouble.

Re:Not a fan of (P/NG/LT/Berkeley)SPICE (4, Informative)

Andrew Sterian (182) | more than 5 years ago | (#28913011)

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.

Re:Not a fan of (P/NG/LT/Berkeley)SPICE (2, Interesting)

sdot1103 (939642) | more than 5 years ago | (#28913059)

I just spent the past summer doing research at the 22nm level (designing L1/L2 caches with DVFS and other low-power techniques) and I can't agree more on SPICE/HSPICE's inability to converge.

I shrunk my designs down to the criitical paths (~12k transistors), and even providing the proper nodesets/initial conditions HSPICE was unable to converge or segfaulted quikcly. Fortunately, my university has a deal with Cadence through their University Alliance program -- Spectre may not be quite as accurate at HSPICE for analog circuits, but both it and Ultrasim (a FASTSPICE simulator for large designs) can handle much larger digital designs without complaint.

To the original submitter: Is there a good reason behind the no network connection requirement? If the university has a proper setup, students should be fine either on or off campus -- then it may be worth checking if your university has any deals with either Cadence, Synopsys, or Magma -- their tools are primarily Unix-based (Solaris, AIX, and Linux support), so it's just a matter of having the students SSH in with X forwarding or use VNC. This would even allows users with underpowered machines to simulate large designs quickly since everything is done remotely. I primarily run Windows on my local box, but either VMs with Linux or using Putty with Xming work properly for all these tools.

Re:Not a fan of (P/NG/LT/Berkeley)SPICE (0)

Anonymous Coward | more than 5 years ago | (#28913993)

I think accuracy of hspice vs spectre is a myth. Accuracy depends largely on your models and simulator settings; also, if the foundry only supports hspice, then of course it will be more accurate vs re-writing or translating it on spectre. By the way, spectre can now understand hspice models.

Nowadays, spectre is getting more a more support with big fabs like TSMC and in home design with fabs. Why? Large capacity, convergence, reliability and accuracy. Hspice, well, if you don't care about reliability.
Accuracy-wise, I depend on spectre for correctness/accuracy and my customers (you) depend on it. I design for automotive safety applications (airbag deployment sensors) and must pass very rigorous automotive test/safty standards (now rivaling, even surpassing military standards a decade ago); unlike commercial/consumer applications.

Spectre is very accurate and reliable.

QUCS (1)

gardyloo (512791) | more than 5 years ago | (#28912725)

I've never used it on Windows, though I see there's an installer for it. I use qucs on linux quite a lot, though. []

Re:QUCS (0)

Anonymous Coward | more than 5 years ago | (#28913135)

I also use QUCS, but mostly in Windows. It is a simple to learn program that has a very similar look and feel to Agilent's ADS. It also does circuits from DC to multi-gigahertz +.

LTspice (0)

Anonymous Coward | more than 5 years ago | (#28912751)

LTspice & TINA-spice (2, Informative)

The Lerneaen Hydra (885793) | more than 5 years ago | (#28912799)

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.

Use LTSpice (1)

kpainter (901021) | more than 5 years ago | (#28912839)

FREE! It is Windows only but runs great on Wine. The author supposedly is very supportive of making sure it runs well on Wine. []
It is optimized for analyzing switching power supply circuits so it probably is the fastest spice implementation out there. I have quit using all the other spice based simulators out there in favor of LTSpice. User support can be found on the yahoo group: []

Electric CAD (1)

jhmorris8541 (981083) | more than 5 years ago | (#28912855)

Try Electric CAD ( in combination with LTSpice (previously mentioned).

I don't know... (3, Interesting)

thatskinnyguy (1129515) | more than 5 years ago | (#28912863)

I don't know if it's been mentioned already or not, but Multisim from National Instruments is a very good software. It's been used by the professors at the school where I work for as long as I can remember.

Re:I don't know... (0)

Anonymous Coward | more than 5 years ago | (#28913753)


Re:I don't know... (0)

Anonymous Coward | more than 5 years ago | (#28914049)

Yes, true, Analog Devices even offers a free version of it.
It is not bad, personally I prefer LTSpice for the job.

SwitcherCAD is free and is supported under WINE (0)

Anonymous Coward | more than 5 years ago | (#28912949)

If you can get over the fact that it's a basically a marketing tool for Linear Technologies, SwitcherCAD is pretty easy to get working under WINE (I think it's an officially-supported way to run it, actually). The standard set of components is focused on prototyping power supplies, but I've had good luck importing PSPICE macromodels from other manufacturers into my library. Of course, if you get to that point, you'll probably have to set up the library yourself and give the students a package -- it's possible to do, the formats are straightforward and there's some information on the net, but it's not for the faint of heart and certainly not for students just trying to simulate a circuit.

Of course I don't know how much you want your students to be able to do. SwitcherCAD only does schematic capture and simulation; you'd have a hard time going from the schematic to board artwork, for example, and there aren't really any reasonable digital logic components (I was able to import some Philips models into my own components for this purpose, but they didn't simulate very fast). But if all you want to do is simulate the guts of a 741 and plot voltage and current over time, it will probably do the job pretty well.

Intel Macs can run Windows (1)

vilain (127070) | more than 5 years ago | (#28913019)

MacOS X 10.5 ships with BootCamp which can boot a Windows partition (Parallels and Fusion can use this partition for their copy of Windows) and run it instead of MacOS X.

There are two commercially available to run Windows on MacOS X. Parallels and VMware's Fusion both require a commercial FULL RETAIL copy of Windows to run a Windows application in a virtual environment (not emulation).

There's also Crossover for Macintosh that can run _some_ Windows applications like Office without installing Windows.

The Linux users are out of luck it seems, but if you use SPICE instead of your Windows-only solution, everyone wins.

Bootable gEDA CD (0)

Anonymous Coward | more than 5 years ago | (#28913041)

Since windows, mac and linux are generally all being run on the same hardware these days perhaps the bootable live linux CD would be a option for your students.

There is one already available for the gEDA 2007 suite.

I recommend repacking a live ISO image with your own customizations. This could provide the same environment and tools to all your students saving each class the hassle of custom building these tools.

A cool toy (1)

wayward_bruce (988607) | more than 5 years ago | (#28913043)

I like to use this, please don't laugh, I am an electronics novice. [] It may be too simplistic to warrant being mentioned along the likes of OrCad, Spice, etc. but boy, does it help build intuition!

KTechLab (1)

mtemmerm (1604279) | more than 5 years ago | (#28913077)

I don't use it frequently, and I'm an uber novice at electronics, but a couple of months back I was looking for a decent simulation app as well, and out of all the ones I tried (most of them referred to above), KTechLab came out as the best option for me. Just my two cents.

LTSpice(SwitcherCAD) (0)

Anonymous Coward | more than 5 years ago | (#28913089)

LTSpice formerly known as SwitcherCAD is a good one. Its available on Linear Technology's website along with some other great SIM tools No limit of the number of nets. Runs on Linux too and it's a free full version.

Edacious (0)

Anonymous Coward | more than 5 years ago | (#28913093)

Edacious [] . It's open source, and runs on Mac and Linux, but is still in beta. Currently only DC and transient analysis are supported by its simulator, but it can export simple circuits to SPICE.

You didn't hear it from me, but... (0)

Anonymous Coward | more than 5 years ago | (#28913099)

You can download the fully functioning demo of CircuitMaker 2000 here []

Install it with Wine. It will run for 30 days. Delete ~/.wine, reinstall.

Or if you want students to really learn SPICE, use WinSPICE [] from Hong Kong Polytechnic, and teach them to build netlists by hand.

Real world experience (1)

hntd (1607149) | more than 5 years ago | (#28913115)

In my time at companies like IBM and Intel they make heavy use of commercial spice and pspice. So students learning to simulate on those software kits will feel like they are learning something they can use in thier working life. Also IBM and intel have internal extensions to the open source versions which I obviosly can't discuss in detail but they exist and students who want to possibly extend those programs can do so and be company supported.

Linux? (2, Insightful)

GWBasic (900357) | more than 5 years ago | (#28913125)

What about Linux circuit simulation software? At least that can be run in a VM for free.

Re:Linux? (1)

aztracker1 (702135) | more than 5 years ago | (#28913253)

That was my first thought... a VM for VMware player or VirtualBox would be pretty easy... depending on size constraints could be copied pretty easily as a pre-setup VM.

Re:Linux? (3, Interesting)

bemasher (1610233) | more than 5 years ago | (#28913285)

I've used Oregano on Ubuntu with not very many problems. My original reason for trying it out was that the academic demo for OrCAD wouldn't simulate circuits large enough for my projects at school. I've found that it duplicates most of the features we used in courses on OrCAD. Oregano []

Logic Works (1, Informative)

Anonymous Coward | more than 5 years ago | (#28913143)

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

Windows free for S.T.E.M. (1)

goobster (880542) | more than 5 years ago | (#28913197)

FYI- Cost shouldn't really be a factor for acquiring Windows for your students. The Microsoft Windows operating systems are free for students in Science, Technology, Engineering, and Math. Ask around- your university should have a MSDNAA repository for students to check out Windows for free. They're also aloud to keep their license once they graduate. [] If you can't find multiple platform software that meets your needs, perhaps virtualization isn't a bad idea.

LTSpice all the way! (0)

Anonymous Coward | more than 5 years ago | (#28913361)

I have used it in windoze and running under wine and it rocks! It has many special features people don't seem to know about including the ability to use .wav files as input and to create .wav files as output. You can simulate a LPF circuit with a square wave input and output a .wav file and hear what a LPF does. I made an instructable here:
It in the contest so vote for me if you like the 'ible!

Get the real thing. (1)

140Mandak262Jamuna (970587) | more than 5 years ago | (#28913413)

Ansoft is the world's leading provider of FEM based design software. They also have circuit simulation products Designer Nexxim etc. All have free student versions. It is something your students can put on their resume.

Re:Get the real thing. (1)

Moof123 (1292134) | more than 5 years ago | (#28914075)

As a professional who's used Ansoft Designer, I can't say enough bad things about it. While it may do OK for college level problems, please only allow students to use it after strongly worded warning about just how buggy, incomplete, and poorly engineered the product is. Under no circumstances should students be allowed to walk away with the impression that Designer is a useful tool. My $0.02.

How long is the class? (1, Informative)

hairyfeet (841228) | more than 5 years ago | (#28913523)

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.

Ngspice + Kjwaves (1)

eudean (966608) | more than 5 years ago | (#28913717)

I did some basic simulations in Ngspice using Kjwaves as a waveform viewer and it worked pretty well for my purposes (I did end up editing a little of the Kjwaves code to fix some issues I had with autoscaling axes, but it was pretty minor). The interface is comparable to using HSPICE + Awaves in my experience. []

Anonymous Coward (0)

Anonymous Coward | more than 5 years ago | (#28913787)

I have an Idea......Teach your students to analyze circuits manually. In 30 years of analog design, I have had only one simulation that told me something I hadn't already discovered with a quick manual analysis. Even though the simulation predicted a problem. It only warned me there was a problem. The problem the simulation predicted didn't exist in the real circuit. Instead the real circuit had a problem far more serious and difficult to fix.
Far more useful to your students will be an understanding of the effect of capacitance and non linearity in the feedback loop or the effect of capacitance at the summing junction. Also an understanding of how real devices differ from theory is also a good idea.
34 years ago I had a professor warn us that simulations were useful if you knew how to sort the useful data out of the reams of data simulators produce. In the years since, this is still sound advice.
Finally teach your students that they need to build the circuits they design. The electrons follow the rules, we have to discover what those rules actually are.

Designworks (1)

chriso11 (254041) | more than 5 years ago | (#28913865)

Check out Capilano's Designworks. There is both Mac & Windows (no Linux) versions. I have used several different schematic capture packages, and Designworks is really very good. In all honesty, I have found Orcad to crash way too often. In fact I've had Orcad crash so bad that a reinstall was necessary. Thankfully, this was an older version (11 I think).

Java Applets... (1)

Curly Top (1157673) | more than 5 years ago | (#28913953) [] There's a bunch of Java applets here that I've always found useful. Not sure if it'll do EVERYTHING you want, but for circuitry the "Analog Circuit Simulator Applet" would likely be sufficient. Plus it's got a lot of other potentially related applets.
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