This project’s a port from a Java application, but the fact it’s built in HTML5 means it’s accessible in every modern browser. This electronic circuit simulator is highly interactive giving the feeling of playing with real components. It’s very helpful for experimentation and visualization. You can add in all kinds of components, wires, and whatever else you need to see exactly how a circuit will work with the help of the web app. This means that this could be useful when you are actually creating these things in real life. You can go to Lushprojects site to check for more details and look through the video demo that takes you through the basics of using it.
Click here to open the simulator in a full window.