When purchasing DC sockets, it is generally expected to buy a product with a long lifespan and good quality. As for switch sockets, the quality of the copper foil inside directly determines its quality. Today, let's talk about how to distinguish the quality of copper sheets for switches and sockets.
1、 Materials
Copper sheet material is the main factor determining the function of copper sheets, which used to be mainly pure copper material. In terms of function, purple copper is the best, followed by red copper, and brass is the worst. Due to the limited antioxidant properties of pure copper, copper alloys are now commonly used, including copper cadmium alloys, copper nickel alloys, tin copper alloys, and the most functional is tin phosphorus copper alloys.
2、 Length
Under the same material conditions, the longer the copper sheet, the better. Because the length of the copper strip determines the size of the socket spacing, the wider the distance between the sockets, the more convenient it is for two or three plugs to be inserted simultaneously. Many old style sockets used to have short copper strips, which caused the sockets to be too short to be plugged in two or three at the same time.
3、 Thickness
The thicker the copper sheet, the better the elasticity, and the corresponding socket lifespan will also be longer.
4、 Forming method
The old-fashioned riveted copper sheet can significantly show that the materials at both ends are completely different from those of the middle bridge, and there are significant riveting points. The copper sheet formed in one go has lower resistance, lower relative heat generation, better elasticity, higher safety factor, and higher conductivity compared to riveted ones.
5、 Touch method
There are two main touch methods for socket copper sheets and plug conductive sheets: point touch and surface touch. Face touch has much higher conductivity and safety than point touch, because point touch is prone to sparks and copper sheets are more prone to loosening.

Classification of DC sockets
DC sockets can be classified into different types according to different classification methods. According to the shape, DC sockets can be divided into two types: direct insertion and side insertion. Direct insertion socket plug is parallel to the socket, suitable for horizontally installed equipment; The side plug-in socket plug is perpendicular to the socket and is suitable for vertically installed equipment. According to the number of interfaces, DC sockets can be divided into two types: single port and multi port. Single port socket only has one interface, suitable for simple power connection; A multi port socket has multiple interfaces and is suitable for power connection of multiple devices. According to voltage level, DC sockets can be divided into two types: high voltage and low voltage. High voltage sockets are suitable for high voltage power environments, while low voltage sockets are suitable for low voltage power environments.

Definition of DC power socket pins
The DC socket is composed of three pins. Pin 1 represents the common pole, which means negative pole. Pin 2 and pin 3 are the same pole, which means positive pole. Pin 2 uses internal power, and pin 3 uses external power.
During normal use, pins 2 and 3 are in a conductive state. With an internal power supply, when an external power supply is inserted, pins 3 and 2 are disconnected, and pin 3 is directly connected. The external power supply is supplied through pins 1 and 3, and pin 2 is now disconnected.