Power adapter, also known as external power supply, is a voltage conversion device for small portable electronic devices and electronic appliances. It is commonly used in small electronic products such as mobile phones, LCD displays, and laptops.

What does the nominal voltage and current of the power adapter mean? First of all, the nominal voltage of a general power supply refers to the open-circuit output voltage, that is, the voltage when there is no external load connected and no current output. Therefore, it can also be understood that this voltage is the upper limit of the power supply output voltage.