38KHz generator for IR LED

Discussion in 'General Electronics Chat' started by mehalaelango, Sep 10, 2012.

  1. mehalaelango

    Thread Starter New Member

    Aug 31, 2012
    1
    0
    Dear everyone,

    I have a design of 38KHz generator for IR source. The problem is practical value differs lot from theoretical. I know the resistance tolerance will affect the output and also i want to know if any other parameter affects the frequency. Please give your advice.
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,647
    2,346
    Hello,

    Can you post a schematic?
    The capacitor in the timing circuit may have a large tolerance.

    Bertus
     
  3. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,172
    397
    At 38 k Hz, timing cap is small & film type, relativley stable. Tolerance not a problem because timing R is part pot. The IR receivers I've tried had broad tuning, several k Hz wide.
     
  4. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    Based on the information supplied, the frequency will vary from between zero and infinity.

    Post schematic and parts list for a real answer... but don't expect anyone to actually search out the specs of all the parts. That's your job.

    We can point you in the direction. We're not going to do your grunt work for you.
     
  5. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    I would use a 555 circuit, but it is probably not as stable as you probably want. This is a situation where more information is needed.
     
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