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 networks

  1. May 18, 2008 #1
    This is not homework, but a question I have posed for myself.

    In a linear, passive, 3-terminal RC network for sinusoidal voltage input how many resistors and capacitors are required to give an open-circuit voltage gain of 2?

    I've found some very complicated networks, but I'd like to find one with the fewest number of R's and C's.

    Thanks for any help.
  2. jcsd
  3. May 19, 2008 #2


    User Avatar
    Science Advisor
    Gold Member

    No combination of resistors and capacitors without some active device such as a transistor will exhibit any gain at all.
  4. May 19, 2008 #3


    User Avatar

    Staff: Mentor

    This question is still coursework, so I've moved the thread to Homework Help.

    bobbyk, do you understand what ASN is saying? How can a passive network have a gain > 1? What do you need to add to get a gain > 1?
  5. May 20, 2008 #4
    Yes, I understand what ASN is saying and he is wrong! You don't need to add anything to
    get a gain > 1. Even very simple passive RC networks have open-circuit voltage gains > 1.

    But I'm trying for a gain of 2.
  6. May 20, 2008 #5

    The Electrician

    User Avatar
    Gold Member

    There was a thread on the Usenet group alt.binaries.schematics.electronic on 10/10/07 with the subject:

    Epstein paper--Synthesis of Passive RC Networks with Gains Greater than Unity

    One of the responders posted this circuit which seems to be able to give gains much greater than just 2. It has practical problems, however.

    http://img2.freeimagehosting.net/uploads/8aad345024.png [Broken]
    Last edited by a moderator: May 3, 2017
  7. May 21, 2008 #6
    Thanks so much! This Is exactly the type of thing I'm looking for!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook