Charger humming?

[jjk454ss]

I have a charger/surge protector with 2 USB ports and 3 outlets. I just put it near my bed, so maybe it's always hummed and I never heard it till now, but when I plug in my iPhone or ipad it starts making a humming sound. Is this normal? Any reason not to use it?

 

[westom]

... but when I plug in my iPhone or ipad it starts making a humming sound. Is this normal?

Coils are wound and then sealed with a varnish (or equivalent). So that winding do not vibrate. Sometimes the winding is not tight and varnish fails to seal that wire. You are hearing the wire vibrate. That vibration typically causes no threat to human life or electronics. And would become more obvious due to how some reactive appliances consume power.

 

[jjk454ss]

Coils are wound and then sealed with a varnish (or equivalent). So that winding do not vibrate. Sometimes the winding is not tight and varnish fails to seal that wire. You are hearing the wire vibrate. That vibration typically causes no threat to human life or electronics. And would become more obvious due to how some reactive appliances consume power.

Thanks. I thought it was fine, but I didn't want to take a chance so etching was wrong with it and it would do something to my devices plugged in to it. Wrong voltage or something strange.

 

[Dennis187]

At least yours sings for you, give it a plus.

 

[jjk454ss]

At least yours sings for you, give it a plus.

Except I'm trying to fall asleep.