A power adapter is a small portable electronic device that typically consists of a casing, transformer, rectifier circuit, filter circuit, voltage regulator circuit, and other components. Its design aims to ensure the safe and stable operation of electronic devices. Power adapters are widely used in various portable electronic devices, including but not limited to laptops, tablets, smartphones, digital cameras, game consoles, etc. These devices typically use built-in batteries for power supply, but the battery life is limited, so they need to be charged or powered through a power adapter connected to the grid.

The working principle of the AC power adapter is based on the principle of electromagnetic induction. After passing through the power adapter, the AC power is first adjusted by the transformer to regulate the voltage, then converted into pulsating DC power through the rectification circuit, and finally removed from the DC noise through the filtering circuit to make the voltage more stable. Finally, the voltage regulator circuit completes precise control and regulation of the output voltage, and activates the protection circuit when necessary.