Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Understand how a low pass filter

  1. May 6, 2004 #1
    Hi, I'm new into this subject.

    I'm trying to understand how a low pass filter (where the frequency f is from 0 Hz to [tex] f_u [/tex] ) for a speacker is working. The fuction for the low pass filter is [tex]\mid H \mid = U_out / U_in[/tex], that is

    [tex]\mid H \mid = R / \sqrt{R^2 + ( \omega L )^2}[/tex]


    [tex] \omega = 2 \pi f [/tex]

    That I don't really understand is how [tex]f \rightarrow 0 \Rightarrow \mid H \mid \rightarrow 1 = \mid H \mid_max [/tex] (f is the frequency) and [tex]f \rightarrow \infty \Rightarrow \mid H \mid \rightarrow 0 [/tex]. I believe that I would need a graph.
    Last edited: May 6, 2004
  2. jcsd
  3. May 6, 2004 #2
    Gm, I've reckoned it out, I quess it was too persceptible to percieve, sorry.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook