Laptop power adapter in the ring is how is it?
Is the voice of the transformer, do not have to buy, will be used on the line.
Notebook power adapter generally use the switch circuit, the output 12V DC power supply, as the notebook DC / DC converter circuit power supply;
In the switch circuit, the most prone to "creak" sound is the switch transformer coil (ringing), or high-voltage filter capacitor (fire);
Inductance and capacitive shock sound
In fact, any inductance and capacitance work will be shocked, but some shocks are large, and some shocks are small, the frequency is not the same, and some sounds harsh, some not harsh, and some ears can not hear the range Inside. Of course, this noise also has a certain standard, in fact, listen carefully, a lot of more power consumption of electronic equipment (tens of watts or more) have a voice.
So, as you said to hear the sound is very small, sharp degree is not the same.
This do not control, as long as they can endure, the general sound is not great, rest assured that good use of the performance and stability of no effect.
