Why I got dirac

Hi,

why I got dirac in result:

a=ilaplace((134.66666666666666666666666666667*s - 134666.66666666666666666666666667)/(s^2 + 1000000.0) + 0.09046252753979897587299774386338);

a=(404*cos(1000*t))/3 - (4627111433557333*sin(1000*t))/34359738368000 + (3259256042553855*dirac(t))/36028797018963968;

What does it mean form me?

Answer 1

[Mischa Kim]

Hello John, the "why" is pretty easy: in the transfer function you have a contstant term (0.0904..). This constant term produces the dirac when you are taking the inverse Laplace. What it means for you depends on the particular problem you are trying to solve. I am just guessing right now, but is the constant term really supposed to be there?

[john]

Hi Mischa, I got result with constant from previous calculation of two matrix like y=a*b.

I solve electric circuit, AC, DC and transient analysis.

What is your opinion? Should I take dirac like 1 or 0?

Thank you

[Mischa Kim]

John, since I do not know how the circuit looks like and what you are calculating the inverse Laplace of it is impossible to say. As an example, if you look at the voltage-current relationship for an ideal inductor, a current step results in a dirac voltage. In other words, if your computations are correct, I recommend looking at the physics of the problem to try to explain why you get the dirac.

[john]

OK, thank you