Skip to main content
G
Giani_Braescu1-Visitor
1-Visitor
February 19, 2019
Question

Laplace Circuit Analysis "Replace complex values and NaNs by real numbers"

  • February 19, 2019
  • 3 replies
  • 6262 views

Hi,

 

I'm trying to make a template that can be used for circuit analysing using Laplace transform.

Here, we have a second order RC lowpass filter and I want to use an repetitive input signal.

In V2(s) equation, where we have the input voltage I would like to use the f(s) input function or even better g(s) repetitive input function.

In the file attached you can see that I have 3 plots: one with input voltage as a constant, where it works and the plot is ok, and another two using f(s) and g(s), where it returns this error "Replace complex values and NaNs by real numbers".

What can be improved in order to use the repetitive s domain function?

 

Mathcad using is Prime 4 and you cand find attached a .pdf too.

 

Thanks.

 

3 replies

W
Werner_E25-Diamond I
25-Diamond I
February 19, 2019

Try to evaluate V.2_f for, lets say, t=10^-5, numerically!

You run into an overflow error - the calculation of a subexpression yields a result greater than the numerical limit of 10^307 and throws an error.

-
-MFra-21-Topaz II
21-Topaz II
February 19, 2019

Hi,

Although realized with mathcad15, you can rewrite it in Prime. You should proceed in this way:

Simple network transitory.jpg

-
-MFra-21-Topaz II
21-Topaz II
February 23, 2019

Hi, 

I enclose the Mathcad 15 worksheet related to your problem and which you can easily import into Prime. Learn the art and put it aside...

Simple network transitory 2.jpg

G
Giani_Braescu1-VisitorAuthor
1-Visitor
February 25, 2019

Hi @-MFra-,

 

If i rewrite your input signal, when I try to plot returns the following error: "This value must be a real number"

mathcad laplace.jpg

LE: I solved this step, I will go on and return with news.

ttokoro
21-Topaz I
ttokoro21-Topaz I
21-Topaz I
February 23, 2019

CR2-10.png

t.t.
G
Giani_Braescu1-VisitorAuthor
1-Visitor
February 25, 2019

Hi @ttokoro,

 

Can you please give more details? I really don't undestand what you did there.

 

Thanks.

Terms & ConditionsAccessibility statement