Circuit simulation exercises for beginners

[TheKnight]

Hi guys.

Any recommended beginner circuits to get me going. I am using Proteus and also have Multisim. Also, which do you recommend using of these two? Any circuits with explanations the basic theory and practise? Help is very appreciated. It can be anything, flashing leds, smaller circuits and then progress. Thanks. Cheers.

 

[simonbramble]

I would start with a dc voltage applied to an RC circuit. You can then see the capacitor charging exponentially through the resistor. Try the same with an inductor. You can then try an ac source, vary its frequency and see the low pass filter effect of the RC network. Change the R and C around and see the high pass filter effect of the RC (series C and R down to ground). This will enable you to get your head around dc and ac simulation which covers most of the simulation scenarios you are likely to encounter.

I also recommend LTSpice - free and much easier to use:

LTSpice tutorial:
http://www.simonbramble.co.uk/lt_spice/ltspice_lt_spice.htm

 

[TheKnight]

I downloaded a version and it says LTspice IV. Is that a wrong version or is there another that I need? Can't see much going on here.

 

[crutschow]

I've used Electronic Workbench from Multisim extensively and it's the easiest SPICE program I've used, so I recommend that. It's better as doing a virtual workbench than the others. You can drag various instruments (oscilloscope, function generator, bode plotter, etc.) to the Workbench schematic window, hook them into the schematic at the points you want to measure, and simulate from there. It also has neat options like allowing you to change certain parameters (operate a switch or change a pot value) from the keyboard and observe the results while the circuit is running.

LTspice is also good but not quite as easy to use, I think.

 

[Sceadwian]

No the learning curve of LTSpice is very Spice oriented, which means HIGHLY technical, not good for starting out.

 

[TheKnight]

So is Multisim a good program to start with? I think that Proteus is more PIC oriented.

 

[Sceadwian]

Proteus isn't really more pic oriented, it is however a for sale only product there is no free version. Multisim NI has a trial version that is free. You will pay for all the features that both software products provide. LTSpice is a raw 'naked' Spice simulator, no fluff or cushioning to new users, but still fully functional and completely free always. If you think you have it in you to tough out the learning curve of understanding how to use spice LTSpice is a very good choice, and it will expose the naked reality of the difference between simulators and real world components much more readily than products like Proteus or Multisim which just want to make a simple easy to use interface that's familiar to people using basic dev tools.

I'd recommend LTSpice myself but it's a mountain to deal with learning how spice works and how real world electronics work both at the same time. The nice thing about basic spice is you can probe voltage current, do FFT or basically any mathematical modeling on the simulation data you want to see what's going on.

 

[andrewblog]

I just found a Virus laden site deleted - moderator on Microcap 9.
I have used Microcap and LT only. But I heared that the demo version of Microcap features more functions than others.

 

[TheKnight]

Sceadwian - I noticed a lot of mentioning of SPICE on Multisim, although I don't understand it. It's a standalone program or a built in Multisim? Because I noticed LTSpice simulator which was for simulating. So are they two completely different programs or in one?

P.S. - Can the admin please ban andrewblog? Noticed that the account is a spam account putting virus links everywhere.

 

[andrewblog]

P.S. - Can the admin please ban andrewblog? Noticed that the account is a spam account putting virus links everywhere.

Your request has been sent to the administrator.
Best regards

 

[TheKnight]

Who are you?

 

[andrewblog]

I' m just a forum user, as you are.
Can you tell us something more about spam and virus contents?

 

[TheKnight]

The link that you sent me was a virus which I am completely sure. You can edit the post later but it was virus. Don't know about the other posts, and sincerely I don't care.

 

[TheKnight]

If I was wrong about you, but I don't think that I was wrong. The link you sent me when I opened it it showed me a virus which restarted my PC. Maybe it wasn't on purpose I don't know. If it wasn't on purpose, sincere apology.

 

[andrewblog]

Do you mean the Microcap pdf tutorial?
I did not make it. I just found it by Google. However on my pc (old model) works fine, though it takes some seconds to open the pages. Do you have Acrobat Reader on your pc?
And do you use Google Chrome? That may be the cause.
Since I use Google Chrome I can see the pdf documents, but I can not print them. If I try, than I must reset the pc.

 

[TheKnight]

The Microcap tutorial yes. I didn't say that you made it I said that If you knew it was a virus and still you posted it. Anyway, I have yes.

 

[Nigel Goodwin]

The Microcap tutorial yes. I didn't say that you made it I said that If you knew it was a virus and still you posted it. Anyway, I have yes.

There seems no reason to blame any users here for spurious virus laden websites, I've deleted the link - perhaps you should invest in some decent security software?, Norton 360 blocks acccess to the site and displays a very clear warning.

Moderator.

 

[crutschow]

........ I noticed a lot of mentioning of SPICE on Multisim, although I don't understand it. It's a standalone program or a built in Multisim? Because I noticed LTSpice simulator which was for simulating. So are they two completely different programs or in one?

SPICE is a general purpose, command line entry, circuit simulation software that was developed at Cal Berkeley (Google Spice Simulator). It forms the basis for most (if not all)available commercial circuit simulation programs, such as Pspice, Electronic Workbench, LTspice, Microcap, and many more. The commercial programs add a user friendly graphical interface including schematic entry, automatic signal plotting, etc.

 

[Sceadwian]

Spice is the simulation code itself, the mathematics that runs the results you see on your screen. Spice itself has been a stand alone language for many years, multisim and various others like Protues use Spice, but they provide a LOT of additional layers on top to make it all look pretty and easy, Spice itself is hardcore mathematics.

 

[TheKnight]

Sorry for the very late reply and thank you for the explanation.