Online Circuit Simulator

erco

I just found this nifty website that does circuit simulation: http://www.falstad.com/circuit/ There's a Java applet that self-loads, so if nothing happens for you, download the Java plugin.

Probably old hat for the EEs here, but it was new to me and I found it fun (educational) to see the voltage & current values for the simple circuit simulated in "real time". Still plenty of applications for analog circuitry. Other than death & taxes, we do live in an analog world...

Also interesting is how you can share circuits you make with other people. For instance:

Here is the SPICE for the 1 transistor signal clipper:

$ 1 5.0E-6 119.19350207351468 77 5.0 50
v 144 368 144 96 0 0 40.0 5.0 0.0 0.0 0.5
w 144 96 256 96 0
t 256 272 368 272 0 1 -4.99999999889 1.0999999999041585E-10 100.0
w 256 96 368 96 0
r 368 96 368 256 0 10000.0
w 368 288 368 368 0
w 368 368 144 368 0
w 368 256 448 256 0
g 368 368 368 400 0
R 480 80 576 80 0 5 100.0 0.7000000000000001 0.0 0.0 0.5
r 192 160 192 272 0 2200.0
w 192 272 256 272 0
x 73 240 101 246 0 24 5V
x 465 265 585 271 0 24 5V inverted
x 450 62 544 68 0 24 1V pulse
g 576 96 576 112 0
w 192 80 192 160 0
w 192 80 480 80 0
o 7 64 0 34 7.654505172902097 9.765625000000001E-205 0 -1
o 10 64 0 35 0.5846006549323611 1.8268770466636287E-4 0 -1

Copy the SPICE code into the clipboard, go to http://www.falstad.com/circuit/ with a JAVA enabled browser and select File Import to get the circuit diagram.

mindrobots

Thanks!

Sure is fun to play with on a conference call!! (sorry, that may not give people a good sense of the fun level!)

Beau Schwabe

You can also download the 'core' files, so that you can run it off-line ... such as while you're in an air plane. :-)

LoopyByteloose

SPICE in general is only as good at the component database that is provided with it. So an on-line solution may be more useful for people that cannot keep up with changes to the component database.

Q*bert

Very nice erco. Thanks!

train nut

Although it doesn't give a real time response LTSpiceIV available from http://www.linear.com/designtools/software does a wonderful job of circuit simulation for both AC and DC as well as Transient analysis. I have used it to design antialiasing filters for my data acquisistion system. I also am designing some analog instrumentation amps for accelerometers.

Heater.

LTSpice is one of my all time favorite programs. It's a Windows program but happens to run perfectly under wine on Linux.