The power adapter is also called external power supply (switching power adapter). It is a small portable electronic device and power supply transformer of electronic appliances. The 220V power supply voltage is used in the home, the general power supply voltage for general electronic products is about 5V to 20V. Therefore, the role of the power adapter is very important especially if you go to the United States and other countries. The voltage is different between countries, then 220V to 110V transformer is even more needed.
Power adapters are commonly found in small electronic products such as mobile phones, LCD monitors and notebook computers. It is generally composed of a housing, a power transformer and a rectifier circuit. According to its output type, it can be divided into AC output type and DC output type; according to the connection method, it can be divided into wall-plug type and desktop type. They are widely used in telephone handsets, game consoles, language repeaters, Walkman, laptops, cellular phones and other devices.
In general, the role of the power adapter is the transformer and rectifier. The household AC power is 220v and our computer land is DC 12v (as if it is), so we can be sure that the power adapter is a transformer and rectifier. The adapter is a transformer then AC 220v is transformed by the transformer. There is some consumption during the process and these consumptions will be converted into heat, so it is normal for the power adapter to generate heat.
The transformer is made of silicon steel sheet. After the transformer is energized, magnetic flux is generated. The magnetic flux will cause a force action between the silicon steel sheet, which will cause a humming sound. This is normal. However, the sound of overheating earth is not normal for many reasons:
1. The AC voltage is unstable.
2. The chip is broken.
3. Interturn short circuit
4. Component damage and so on
By the way, the role of the adapter is to convert AC to DC electronics power adapters with large space are usually built-in. Generally, the size of the adapter is not small. Small-sized machines are external. In order to save space, it is also convenient to replace. The mains power used by the adapter is relatively high.
The function of the power adapter is to convert the high voltage at home into a stable low voltage that can work, so that they can work normally. It will bring a lot of inconvenience to our daily use without power adapter.