Transformer hum noise

Discussion in 'General Electronics Chat' started by pradeeba, Jul 22, 2008.

  1. pradeeba

    Thread Starter Active Member

    Feb 27, 2008
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    Hi ,
    How to reduce the transformer hum noise in SMPS which is working in flyback topology?
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Increase the frequency to above the audio range.

    However, if it's an existing design, the transformer will probably have to be replaced.
     
  3. pradeeba

    Thread Starter Active Member

    Feb 27, 2008
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    0
    If i have to increase the frequency of switching, it is not possible, because it is fixed frequency switching. And this is not an existing design. what are all the possible reasons for transformer humming?
     
  4. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63

    The transformer humming is mainly caused by the laminations which are not tight well. These laminations vibrate due to the changing magnetic field in the transformer. Humming may be caused by vibrations of the transformer's hoyusinng or windings.
     
  5. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    A cheap transformer is made with loose parts and no adhesive to keep the parts together.
    A good transformer is made properly and is quiet.
    You get a cheap transformer if you pay a cheap price.
     
  6. vetterick

    Active Member

    Aug 11, 2008
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    I just can't believe my eyes, why the misinformation you get from these forums, everyone knows transformers hum because they dont know the words!!

    Sorry, I just couldn't resist.
     
  7. Audioguru

    New Member

    Dec 20, 2007
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    The only transformer that I have heard make a noise was an overloaded one that made a buzz, not a hum.
    I guess I have never heard a cheap transformer.

    High power incandescent light bulbs sing the words when they are dimmed. They are smarter than transformers that don't know the words. I also couldn't resist.
     
  8. MusicTech

    Active Member

    Apr 4, 2008
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    Please don't apologize, that's fantastic.

    You know if the hum REALLY bothers you, just enter a deep stage of meditation and don't let it bother you.

    Just say ohhhhhhhhhhhhmmmmmm, ha pun fight
     
  9. loosewire

    AAC Fanatic!

    Apr 25, 2008
    1,584
    435
    Reverse the primary.
     
  10. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
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    Torch it or blow it to gibs.
     
  11. pradeeba

    Thread Starter Active Member

    Feb 27, 2008
    104
    0
    What is the need for reversing the primary? if we reverse what will happen to flyback action?
     
  12. yubyub

    Member

    Aug 13, 2008
    19
    6
    ok so, as we all know, transformers can make loud robotic noises when they transform. greasing/oiling their joints should help them transform more silently such that they can do it in stealth easier. are your transformers autobots or decepticons?

    srsly, epoxy is a great idea.
     
  13. loosewire

    AAC Fanatic!

    Apr 25, 2008
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    435
    Post diagram in use ?
     
  14. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
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    Your guess is as good as mine.
     
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