What causes the humming sound in transformers?

In summary, transformers hum due to the changing magnetic flux caused by the AC current passing through the coils, which results in vibrations in the iron core. This is due to magnetostriction, where the iron laminations change dimension when the excitation exceeds 1 Tesla. This phenomenon occurs twice per cycle, resulting in a hum frequency of 120 Hz (or 100 Hz).
  • #1
woollymac
3
0
Why do transformers hum? Is it the iron core vibrating & if it is what is it that makes it vibrate? Is it the little atomic magnetics in the iron changing directions with the ac? Can anyone enlighten me?
 
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  • #2
Basically I think you are right,the coils carry a.c.and this results in the core going through many magnetic cycles per second.The changing magnetic flux then results in vibrations.
 
  • #3
Magnetostriction in the iron causes the iron laminations to change dimension when the excitation exceeds about 1 Tesla. Magnetostriction occurs twice per cycle, so the hum is 120 Hz (or 100 Hz) depending on where you live.
 

Related to What causes the humming sound in transformers?

1. Why do transformers hum?

Transformers hum because of a phenomenon known as magnetostriction. This is caused by the alternating magnetic field produced by the transformer's core, which causes the core to expand and contract slightly, producing a humming sound.

2. Is the humming sound from a transformer normal?

Yes, the humming sound from a transformer is completely normal and is a result of the transformer functioning properly. It is a natural byproduct of the alternating magnetic field and does not indicate any issues with the transformer.

3. Can the humming sound from a transformer be reduced?

Yes, the humming sound from a transformer can be reduced by using specialized materials in the transformer's core, such as laminated steel, which can help minimize the effects of magnetostriction. Proper placement and insulation of the transformer can also help reduce the humming sound.

4. Does the size or type of transformer affect the level of humming?

Yes, the size and type of transformer can impact the level of humming. Generally, larger transformers tend to produce a louder humming sound due to their larger cores and stronger magnetic fields. Additionally, different types of transformers, such as toroidal or shell type, may produce different levels of humming.

5. Can the humming sound from a transformer be harmful?

No, the humming sound from a transformer is not harmful. It is a normal part of the transformer's operation and does not pose any health risks. However, if the humming sound suddenly increases or changes in pitch, it could be a sign of a malfunction and should be inspected by a professional.

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