Thanks DrFPGA! CircuitLab is now the de-facto circuit simulation software of choice at hundreds of universities around the world, with students and faculty telling us that we are swiftly replacing LTspice, PSpice, and Multisim for the next generation of EEs. We've also have a growing number of professional and hobbyist users on our non-free but affordable subscription plans. All in all, the CircuitLab community runs hundreds of thousands of simulations every month!
The problem is models. 99% of the simulators out there come with zero models. And for 99% of the componetns out there you can't even get an accurate model !
i built a simple (4 opamps , a mosfet and some r's and c's) constant current sink. i used all LT opamps and even mosfet that was in LTspice. According to LTspice the thing would oscillate and have all kinds of unwanted behavior. on bench it worked just fine. built over 500 of those and not a single one exhibits the behaviors the simulator was showing me...
the trick ? having a ferrite bead shoved over the gate of the mosfet, correct grounding strategy keeping cross currents at bay and ohter PCb wizardry.
Good luck pluggin that into the sim ... The sim is only as good as the models you feed it. and sadly most models are inaccurate or simply wrong.
opamp in gain x 10, feed it 10 volts, and power it with 5 and -5 ... you'll be amazed how many sims show the output at 100 volts.. ( with 5 volt rails ? seriously ? )
I've used LTSpice almost exclusively for analog simulation for the past several years. Including at work where a lot of us prefer LTSpice to PSpice (to the point where the company has decided to cut down on the number of PSpice seats despite the increase in the number of engineers)
I'm looking forward to learning more about the other simulation software you mentioned.
I have tried Circuit Lab a few times. It is easy to use and for small circuits and since it includes schematic capture it seems just perfect. It runs in your web browser too which is another great feature...