Schematics and Circuit Simulation In the Browser

compumike writes "CircuitLab today released a browser-based schematic editor and circuit simulator for the online electronics community. SPICE-like device models and mixed-mode simulation support allows engineers and hobbyists to tackle a wide range of board-level design problems. While most EDA software is Windows-only, CircuitLab is 100% web-based, Windows/Mac/Linux cross-platform, and requires no installation or plug-ins. Instead of today's typical forum posts with static screenshots from different desktop tools, the online electronics community can now use CircuitLab to share useful URLs (as well as PNGs and PDFs) which link directly to interactive, editable, runnable schematics. In just a few clicks, another designer can open that circuit, make a change, simulate it, and post the new version back to the community."

Falstad's Java Circuit Simulator

[senor_meow]

I think it is important to mention Paul Falstad's Java circuit simulator that has been around for years and has probably influenced this project. http://www.falstad.com/circuit/ [falstad.com]

Pretty cool, although limited

[vlm]

Its pretty cool, although limited.

I checked it out and there's a pretty limited selection of BJTs, etc. Well I poked around and it turns out you can do something pretty cool with just a couple parts, with any luck here's a differential amp, assuming this link works:

https://www.circuitlab.com/circuit/fby849/bjt-cascoded-active-load-differential-amplifier-with-cmfb/ [circuitlab.com]

My guess is they'll soon be releasing a "paid" version where I can use thousands of (official?) transistor models not just 10 or so. That would be pretty awesome.

Also if they know what they're doing they'll partner with a short run PCB house. Some PCB houses give away PCB CAD software, these guys have a jump ahead of them... Maybe they already have, I have not explored the entire site. Imagine doing the schematic, the spice run, the pcb layout, and order some boards (and parts?) from the same browser window... that would be cool. Heck partner with those "virtual front panel" guys too.

If you double click on a component you can change the parameters, I think I could design a nifty little MMIC active constant current biasing circuit by hacking a rectifier model into a psuedo-mmic model (basically crank the forward V drop to 3 volts or so, depending on device, and a couple other things especially device capacitance). I wonder if I can push it into oscillation? (Note, you try to design ckts that don't do that... at least if they're theoretically amplifiers) Or get it to ring into a negative voltage at the amp input by doing stupid inductor tricks (this is why you don't use MMICs at HF freqs, aside from oscillation and usually intentional device gain rolloff)

I'd like to see the ability to handle temperature swings. My parts are milspec individually, but does my overall design work over a whole milspec temp range?

I suppose if I'm asking for the moon, could I have something like Ansoft for waveguide foolishness in my browser window?

Re:This actually looks pretty amazing

[X0563511]

It's a troll within a troll, and you appear to have fallen into the trap (and dragged me along with you) :(

Re:No thanks

[X0563511]

I just created a test schematic, and if I then go in my workbench and select it, I can export it to PDF. Sure, it's not perfect (eg it's not something parsable like an XML), but it also means that your work doesn't go "poof" either.

Re:SPICE/Workbench

[Mitchell314]

I remember multisim, it's a great educational tool for learning patience. And for learning why one shouldn't release software with showstopper bugs.

Re:This is great

[GrahamCox]

This is stupid for motor coils, where you care about resistance at least as much as inductance

So just put the resistance in series. That's fine for simulation, where layout, parasitics, etc, are ignored unless you add them as elements specifically.

Re:SPICE/Workbench

[Anonymous Coward]

http://www.falstad.com/circuit/ [falstad.com] is nicer; it simulates in real time and isn't as clunky because it runs as an applet instead of javascript hackery.

Re:Raspberry PI

[mirix]

Good luck getting the chip out of broadcom without an order for a billion units. (assuming you are equipped to deal with BGA packages in the first place).

Re:No thanks

[Anonymous Coward]

Linear Technology gives away its professional grade circuit sim tools as a way of promoting its hardware sales (full part library comes with it). google LTSPICE. free for noncommercial use. runs on windows. for non-windows there are a number of other good options, but this is the best win32 simulator I've found for teaching students, using on grad school projects, etc.