×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Manipulate RLC circuit impedance in symbolic form

Manipulate RLC circuit impedance in symbolic form

Manipulate RLC circuit impedance in symbolic form

(OP)
Hi all,
I'm looking for software which would help the manipulation of the expressions for the impedance of linear RLC-circuits in symbolic form.The most important feature would be
to extract the real and imaginary part of the final analytic
expression.

The analytic expressions tend to get quite tedious to form on paper even in the case of simple circuits, but for a computer the task should not be a problem...

Using Mathemathica (4.0) I would like to do the following, for example, but the output
is not quite what I'm looking for;
Zm = Rm + I*(Lm*w + 1/Cm/w)
Z0 = I*1/C0/w
Zs = I*1/Cs/w
Ztot = 1/(1/Zm + 1/Z0) + Zs (* impedances Zm and Z0 in parallel, and Zs
in series *)
ComplexExpand[Ztot]

[Actually, I just found out that Mathematica 5.2 does already a better
job ... anyway, it would
be nice to hear your ideas...]

Also from an old posting I learned that a software called TINA might do the job. Also a Maple plugin for symbolic expression is discussiod. Has the scene changed in four years?
The thread is here:
http://groups.google.fi/group/sci.electronics.cad/browse_thread/thread/e812262103272357/2e43a3042d9ed4ee?lnk=st&q=rlc+analytical+expression&rnum=5&hl=fi#2e43a3042d9ed4ee

Thanks for your comments!

RE: Manipulate RLC circuit impedance in symbolic form

Do you need an analytic formula for the result?  If so, you are problably best to just do the math, or, if you are lazy, use Mathematica or Maple.  But unless the circuit is a lot more complicated than your example, you really don't need them.

If you don't need an analytic result, just a numerical one, then I would suggest doing a quick program in a language that supports imaginary numbers naturally, such as Fortran or Python.

Personally, I do this all the time in Python.  Most problems take about 3 lines of code to generate the plots I need*.

*For plotting, there are lots of options, but I would suggest matplotlib, which generates high quality plots and will be familiar to anyone used to Matlab.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources