Help identifying components / function for circuit

Discussion in 'General Electronics Chat' started by diddy02, Jul 20, 2010.

  1. diddy02

    Thread Starter Member

    Sep 26, 2008
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    0
    Hey all,

    I have an IC that takes input from a computer and outputs two high voltage sine waves. The input determines the frequency of the sine waves (are about 40-50 kHz). I've attached a picture of one part of the circuit that I'm having a bit of difficulty understanding. A uC is connected to a DAC, which is eventually connected to a PLL. I don't get what the blue things (pots?) or yellow things are (I've marked them in the picture). I'm trying to understand what is going on from the DAC to the PLL. I'd appreciate any insight or advice!


    -d02
     
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  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
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    The upper blue pot is marked 504, which means 50 with 4 zeros after, or 500k Ohms.
    The lower blue pot is marked 503, or 50k Ohms.
    They may be 10- or 21-turn trimpots.

    I can't make out the part numbers on the yellow rectangular devices.
     
  3. Jony130

    AAC Fanatic!

    Feb 17, 2009
    3,957
    1,097
    This yellow rectangular devices maybe some kind of opto-isolator.
     
  4. StayatHomeElectronics

    Well-Known Member

    Sep 25, 2008
    864
    40
    The first thing that comes to mind when seeing the two "yellow things" is that they are optocouplers. Maybe... Just a thought.

    It looks like the bottem line of the part is 825P281...

    Edit: Most of the 825 parts seem to be dual optos in larger packages though...
     
    Last edited: Jul 20, 2010
  5. SgtWookie

    Expert

    Jul 17, 2007
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  6. diddy02

    Thread Starter Member

    Sep 26, 2008
    10
    0
    Hey all,

    Thanks for the quick reply. There are a couple of step up transformers on the board that I'm having trouble identifying. There aren't any markings that I can see. I don't really understand the pinouts... there are (from what I can tell) 6 input pins on the low side and 8 on the high side. Please see the attached picture. Are there any data sheets for the same/similar transformers?
     
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  7. diddy02

    Thread Starter Member

    Sep 26, 2008
    10
    0
    Hey all, sorry to bump this up, but I'm still having a lot of difficulty ID'ing this part. I generally look on places like Digikey. Does anyone have any suggestions?
     
  8. StayatHomeElectronics

    Well-Known Member

    Sep 25, 2008
    864
    40
    Components like transformers are much harder to identify without additional clues. They could be custom made for the product so their specifications may not be public.
     
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