What kind of part is this and what is it used for?

Discussion in 'General Electronics Chat' started by Management, Dec 4, 2009.

  1. Management

    Thread Starter Active Member

    Sep 18, 2007
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    Thanks for the help.
     
    Last edited: Dec 15, 2009
  2. TheBellows

    Active Member

    Jan 18, 2009
    56
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    Looks like two diodes/rectifiers, but i'm no expert.
     
  3. Management

    Thread Starter Active Member

    Sep 18, 2007
    306
    0
    I thought it was just diodes in parallel but I wasn't sure. Maybe someone else can chime in and let me know what in the world they are doing in that feedback loop.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Those are dual diodes, with pin 3 as the common cathode. The whole network is not visible, so their function is a bit of guesswork. The 680 pF cap is probably a feedforward high frequency suppressor. The ratio of the 100K R38 and the two input resistors, R33 & 35 set the gain in the positive direction... But there is more stuff below the summing junction, so who knows. The two dual diodes are connected so their two diodes are in parallel, and are both in series, and clip the negative signal transition - assuming there is one.
     
    Last edited: Dec 4, 2009
  5. Wendy

    Moderator

    Mar 24, 2008
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  6. VoodooMojo

    Active Member

    Nov 28, 2009
    503
    53
    here is a bit of info on one:
     
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