Why do we study simulators in electronics?

[erece]

my question may be silly .
I want to know why we study orcad or any other simuator software, i mean how powerful are these tools?
I cannot build circuits for my hobby due to cost factor, so is it equivalent to do that on orcad?

 

[DragonPetter]

my question may be silly .
I want to know why we study orcad or any other simuator software, i mean how powerful are these tools?
I cannot build circuits for my hobby due to cost factor, so is it equivalent to do that on orcad?

Your problem of cost is just one of many good reasons for using simulators.

They are not equivalent to the real thing, but it is better than nothing and even has many advantages over the real thing since you can quickly measure things and change them easily. It is ideal to use a simulator and lab prototyping together, since they compliment each other. And yes, if you cannot afford to build the real thing, you can learn close to everything from a simulator if you are using it correctly. Simulators are often much better for learning how a circuit works than building.

Simulators can be difficult to use sometimes though, which require you to optimize the simulator settings or to modify your circuit element models.

I have built circuits that pushed my simulator to the limit in computing and memory on my computer. A good example is a charge pump circuit I made. The circuit is actually switching at a very high frequency, say in the nano seconds of operation, while the output may be on the order of 1-2 seconds. This requires the simulator to make billions of computations and data points and it can halt the simulator or crash the test, which is an obvious drawback to simulating. But, the actual circuit requires a lot of components, software programming, and time to build it all, while the simulator took me maybe 1-2 days to build and play with many different parts and options, without the risk of blowing anything up. So I was able to prove the circuit should work, pick the best parts, and design for the real thing and reduce a lot of risk I would have without the simulator in just a day or two of work.

Another reason is to test all of the possible states of your circuit that would take months to test manually. You can use monte carlo simulations to vary the tolerances and values of all of your components and see the range of outputs you get from these variations. You could almost never do this easily in real life.

 

[skeptic2]

I agree with DragonPetter. In one company I worked for, I had all our circuits modeled in SPICE and got results very close to measured values. Whenever the design team made a change to a circuit, I made the change in the SPICE model and was able to test all the parameters I thought might be affected before the circuit was even built. I have seen SPICE accurately predict the spurs and startup time of an RF oscillator.

There are lots of things you can tweak in SPICE and to get a really good simulation you need to know how to tweak it. There are a few good books on the subject that can help.

 

[erece]

thankz