Getting a nosiy signal to test a FIR filter

Discussion in 'The Projects Forum' started by atferrari, Mar 5, 2011.

  1. atferrari

    Thread Starter AAC Fanatic!

    Jan 6, 2004
    2,645
    759
    I plan to carry a basic test of a FIR filter using an already available 400 Hz sinusoidal signal, contaminated with noise on purpose.

    Had some success to generate noise with the base-emitter diode of a BC338 polarized as a zener.

    My questions:

    a) What should be the simplest way to amplify the noise with an opamp? AC amplifier? I am trying to use several CA3140 (single supply opamp).

    b) To add noise to the signal, I tried to implement a summing amplifier but up to now all I get is the original signal quite clean. Or it is how it looks. (?)

    c) Am I too off track here?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
  3. atferrari

    Thread Starter AAC Fanatic!

    Jan 6, 2004
    2,645
    759
    It can be used (did it yesterday) with single supply. (+ input to Vdd/2).

    I was aware of both links.

    Years ago I bought one MM5837 but couldn't find it so had to resort to an NPN transistor.

    My problem is what comes AFTER that, thus my questions.

    Gracias for replying.
     
  4. bertus

    Administrator

    Apr 5, 2008
    15,645
    2,344
  5. atferrari

    Thread Starter AAC Fanatic!

    Jan 6, 2004
    2,645
    759
    My problem was one pin making no contact at all in the breadboard.

    Results, here you have them. The .asc file is just a drawing for posting here.

    Gracias again.
     
Loading...