cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Showing results for 
Search instead for 
Did you mean: 

inverse laplace

mark_neil2
1-Newbie

inverse laplace

Hi,

I have posted a question at this address: http://communities.ptc.com/message/157195#157195. However, I didn't get responses from many folks but only one person.I still don't have a solution for my question. I believe that there is a solution and someone more knowledgeable about Mathcad can easily answer it. In the past, I used to get several responses for my posts. I thought that maybe I should have posted in "Mathcad usage" section. So, that is why I am posting it here...

I willl appreciate if anyone has solution for my question. Thanks.

Mark.

3 REPLIES 3
LucMeekes
23-Emerald II
(To:mark_neil2)

Your problem as it is posed is apparently easily solved by Mathcad 14, which uses a different symboloc engine from that used by mathcad 13 and previous.

With Laplace transform the maple engine works unpredictable in the sense that you never can tell which formulation of the problem it will solve, and which it won't.

In some cases it helps to reformat the equation. Sometimes a "simplify" before the transform will help, sometimes it will destroy.

You wrote that you derived the expression yourself. My advice is to try to transform a less "simplified" version of your equation, preferrably one that has a denominator of the form s*(s+a)*(s+b)*(s+c). It may sometimes also be wise to keep the expression symbolical until after the transform.

I've added another expression that Mathcad 11 is happy to transform. I've introduced a number of symbols. I guess that, from the knowledge of the circuit, you should be able to write it out with less (in number), but far more meaningfull symbols (being circuit element values).

This file is made in Mathcad 11. It is generally wise to save your files for this forum in Mathcad 11 (.MCD) format, because some users didn't go any further than Mathcad11...

Success!

Luc

Hi Luc,

Your answer was helpful. Thanks.

Mark.

RichardJ
19-Tanzanite
(To:LucMeekes)

preferrably one that has a denominator of the form s*(s+a)*(s+b)*(s+c).

That is a very interesting, and useful, observation.

Announcements