Free Analogue circuit simulation, mainly in LTspice.
The most widely used free circuit simulator is LTspice, however there are other free simulators available, info on these is available at the bottom of this page.
This website is based mainly on providing electronic copies of circuits for use mainly in LTspice,there is some explanatory text on the website and the circuits, but its the circuits that are the main thing here.
I guess its that some of us work better with circuit diagrams rather than a load of text.
Running these circuits in the simulator allows you to see the voltage and current waveforms throughout the circuit without having to build the circuit or buy any test equipment.
In fact you don't need to spend any money at all.
Start off by downloading and installing LTspice from www.analog.com
Then click on the below links to open the various circuit categories, then download the circuits, or the ZIP files if your browser is giving you grief,
Then open the circuit with LTspice, and follow the instructions on the cct diag. to run the ciruit and view the waveforms.
Regarding text on the circuit diagrams, blue text is just comment, black text is read by the spice simulator.
There is comment text on the circuits explaining how to run the simulation and plot the waveforms