Great Online Circuit Simulator Site

Designing electronic circuits takes knowledge and experience. Sooner or later, you have to put your idea to the test. Generally, this means building a prototype. Even with the best circuit simulator software, you ended up with unfriendly or expensive products. Or both. Now you can do a good job with an online circuit simulator tool to test your ideas.

The online circuit simulator from Circuit Labs is a web based circuit modelling solution. It can simulate a wide range of electronic components from simple passive devices like resistors and capacitors all the way up to complex integrated circuits. In fact, you could do the electronic design, and modelling for  your own integrated circuits if you wanted to.

The interface is a delight to use with a palette of sample components readily available. You can easily drag and drop components into your circuit, connect them up, label nodes and specify measurement points. A variety of input sources are provided. Not only do you get the obvious, like voltage sources and current sources, you can make voltage controlled current sources, digital clocks with variable duty cycle. and any combination of these. It didn’t take too long to work out how to make a reasonable model of a phototransistor for example.

Better yet, there is a library of existing designs created by other for you to examine and experiment with or to use as the basis for your own efforts.

Once your electronic circuit is all placed and connected up, you can run several different kinds of simulation. A straightforward DC analysis will let you check quiescent currents and bias levels Then you can move on to frequency response plots or time domain simulation to see how the circuit responds to transients.

A single transistor amplifier example

A simple single-transistor amplifier circuit might look like this:

DC analysis of the circuit gives us the following value:

I will leave it to you to verify that these are exactly what we might expect. Now, an AC analysis can be done to get the overall frequency response of the amplifier. Again, I leave it to you to work out that the results are as expected:

There is a lot more that you can do with this online circuit simulator but here is one more interesting possibility. It is easy to see the effect of changing a component value. Here I have told the simulator to perform the AC analysis with various values for the collector resistor, R3. This will change the amplifier’s gain but will also affect the amplifier’s bandwidth.

And the best bit? Well, at the time of writing, this is all free. Not free as in beer but free as in no money.

Also, in case you don’t think Oracle has your best interests at heart, it does not use Java.

You might want to test out your design skills by working out what happens to the response when R3 is large (9000 Ohms).

Visit the site and have a look for yourself:- http://www.circuitlab.com/