The wholesale power supply adapter is also called an external power supply. It is a power supply voltage conversion device for small portable electronic equipment and electronic appliances. It has a voltage conversion function. Its common product names include power supply adapters, chargers, and power supplies.

The wholesale power supply adapter is generally composed of an external insulating shell and an internal circuit device. Its connection with the grid power supply (mains) is divided into a plug power cord and a straight-in type. The shell of the in-line power supply adapter is integrated with the plug. This form It is also the most widely used case in the power supply adapter (charger) of small portable electronic products. Over the years, my country has been implementing the CCC compulsory product certification management system for wholesale power supply adapter products for information technology equipment and audio and video equipment. With the increasing number of electronic products, the application of wholesale power supply adapter has become more and more popular, which has formed the characteristics of diversity of applicable personnel and use environment, which has increased the risk of product quality and safety. In addition, although the production technology of wholesale power supply adapters is relatively mature, the technical threshold is not high, the cost is low, and the products of small and medium-sized enterprises that lack production quality assurance capabilities continue to flood into the market, resulting in uneven product quality and a high overall sampling failure rate. Therefore, how to improve the quality of wholesale power supply adapter products is a common concern of testing agencies, government regulatory agencies and wholesale power supply adapter manufacturers.