Low pass and high pass filters (newbie questions)

Discussion in 'General Electronics Chat' started by NY10, Aug 2, 2010.

  1. NY10

    Thread Starter Member

    Jul 30, 2010
    Hi, all

    I believe that high pass filter can be made by using low pass filters because low pass filter is the basic one.

    Can anyone explain how it can be done or accomplish ?

  2. tom66

    Senior Member

    May 9, 2009
    The only difference between high-pass and low-pass RC or LC filters is the order of the resistors/inductors and capacitors. Since they have physically different layouts, it is not possible to create one from another.
  3. kingdano

    Senior Member

    Apr 14, 2010

    This is the correct answer.

    Simple passive and low order filters are created by arranging resistors (R), capacitors (C) and inductors (L) in various topologies.

    Adjusting the values will change the effective cut-off frequencies.
  4. Ghar

    Active Member

    Mar 8, 2010
    Keep in mind that in a first order RC LPF the low pass response is across the capacitor while the high pass response is across the resistor. If you really want to go through the trouble of taking outputs across both elements you can.

    Interchanging elements, like inductors for capacitors, will flip what the circuit does as well.