1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: RC Transfer function

  1. Apr 4, 2015 #1
    1. The problem statement, all variables and given/known data
    R = C = 1;

    2. Relevant equations

    G(S) = 1/(s+1)

    3. The attempt at a solution

    Suppose R = C = 1 then the transfer function from the input voltage to the voltage across the capacitor is 1/ (s+1). So Vc(S) / V(S) = 1/(s+1). Getting back to time-domain: Vc(t) = V(t) * e^-t. What's wrong here? It should have been V(t) ( 1 - e^-t ). Thank you!
  2. jcsd
  3. Apr 4, 2015 #2


    User Avatar
    Science Advisor

    How you connect R and C, where do you connect the input and where is the output? As it stands, the question is impossible to answer.
  4. Apr 4, 2015 #3
  5. Apr 4, 2015 #4


    User Avatar

    Staff: Mentor

    What's your V(t)? Suppose that the transfer function is U(s) = 1/(s + 1). You need to deal with V(s)*U(s) if you expect to find the time domain response Vc(t) via Vc(s) = V(s)*U(s).

    It looks like you were looking for the time domain response of the circuit to a step function: V(t) = V*u(t).
  6. Apr 4, 2015 #5
    Thank you!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted