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: Half wave rectifier Ripple Voltage

  1. Jun 5, 2010 #1
    1. The problem statement, all variables and given/known data

    A capacitor of capacitance C is connected in paralell with a resistor of R ohms impedance. Calculate the size of the peak to peak voltage of the ripple produced relative to the peak output voltage Vp.

    2. Relevant equations

    Q=CV
    dQ/dt = I
    V=IR
    Vc=Vpe-t/RC (am i allowed to use this in an AC circuit?)
    or Vc=-jI/R[itex]\omega[/itex]C

    V = Vpcos([itex]\omega[/itex]t)

    3. The attempt at a solution

    Voltage drop across the resistor is just:

    V = Vpcos([itex]\omega[/itex]t)

    Voltage drop across the capacitor can be aproximated to:

    Vc=Vp(1-e-t/RC)

    The alteration to the equation in 2 is to ensure the capacitor voltage is 0 at t=0.

    At t=0

    VR - Vc = Vp

    at t=T/2 or at 1/f

    VR - Vc = Vpe-1/fRC

    The ripple voltage will be the differance between these two:

    VRipple= Vp(1-e-/fRC)
     
    Last edited by a moderator: Feb 7, 2016
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted