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Need help simplifying equation to find the laplace transform of it

  • Thread starter formulajoe
  • Start date
  • #1
177
0
there are two loops in an electrical circuit. ive got two equations and two unknowns.
here are the equations

v(t) = I1*R1 + 1/c*int(I1*dt) - 1/c*int(I2*dt) - first loop
0 = LdI2/dt + R2*I2 - 1/c*int(I1*dt) + 1/c*int(I2*dt) - second loop

the capacitor is in the branch between the two loops.

Im drawing a blank on this. I need to simplify into one equation so I can find the laplace transform of the one equation.
the goal is to find the step response of the system using matlab.
 

Answers and Replies

  • #2
Tom Mattson
Staff Emeritus
Science Advisor
Gold Member
5,500
7
You'll want to differentiate both equations first, to get rid of those god awful integrals.

I need to simplify into one equation so I can find the laplace transform of the one equation.
There's nothing wrong with taking the Laplace transform first and then simplifying.
 
  • #3
177
0
can i get a confirmation that i set up those differential equations properly? im having some trouble with this still. if i differentiate, than i get derivative of the input. im trying to find the output voltage which is across the R2 resistor.
 
  • #4
177
0
im still having trouble with this problem. ive tried multiple methods including differentiation and solving for a variable and plugging it into the first equation but im still where i started the other day. im trying to find an eqation that relates the output voltage across R2 to the input. im confident my beginning equations are correct, but i dont know where to go from there.
 

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