Introduction to Several Common Connectors

(1) Terminal blocks
Terminals are mainly produced for the convenience of wire connection. In fact, a wiring terminal is a metal sheet wrapped in insulating plastic. Both ends of the metal sheet have holes for inserting wires. There are screws for tightening or loosening. Sometimes it is necessary to connect two wires, and sometimes it is necessary to disconnect them. At this point, terminals can be used to connect and disconnect at any time, without the need for welding or wrapping together, making it convenient and fast. There are many types of terminal blocks, commonly used including plug-in terminal blocks, PCB terminal blocks, terminal blocks, screw fixed terminal blocks, grid type terminal blocks, etc.
Terminal characteristics: diverse pin spacing, flexible wiring methods, suitable for high-density wiring requirements; The maximum current of the wiring terminal is up to 520 A; Suitable for SMT production process; Can be used for reflow soldering, with a maximum temperature resistance of 300 ℃; Different accessories can also be used to expand functionality.

(2) Audio/Video Connector
① Two core and three core plug sockets: mainly used for signal transmission between various devices, with input plugs serving as microphone input signals. Two core plug sockets are mainly used for the connection of mono signals, while three core plug sockets are mainly used for the connection of stereo signals. According to its diameter, it can be divided into three types: 2.5mm, 3.5mm, and 6.5mm.
② Lotus plug socket: mainly used for audio and video devices, as an input and output plug for the circuit between the two.
③ XLR plug (XLR): mainly used for connecting microphones and amplifiers.
④ Five core socket (DIN): mainly used for connecting cassette recorders and power amplifiers. It can concentrate stereo input and output signals on a single socket.
⑤ RCA plug: RCA plugs are mainly used for signal transmission.


(3) Rectangular connector
Rectangular plugs and sockets are made of different numbers of contact pairs in a rectangular plastic shell with good insulation performance. The number of contact pairs in plug sockets varies, up to dozens. The arrangement method includes two rows, three rows, four rows, etc. Due to the elastic deformation of each contact pair, the generated positive pressure and friction force can ensure good contact between the contact pairs. In order to improve performance, some contact pairs are coated with gold or silver plating.
Rectangular plugs and sockets can be divided into pin type and double spring type; With and without a shell; There are locking and non locking connectors, which are commonly used in low-frequency and low-voltage circuits, high and low frequency hybrid circuits, and are mostly used in radio instruments and meters.

(4) Circular connector

There are two main types of circular connectors: plug-in and threaded. The plug-in type is usually used for circuit connections with frequent plugging, few connection points, and a current of less than 1A. Screw connectors are commonly known as aviation plugs and sockets. Equipped with a standard rotary locking mechanism, it is more convenient to connect in situations of multiple contacts and high insertion and extraction forces, and has excellent vibration resistance performance; It is also easy to achieve special requirements such as waterproof sealing and electric field shielding, suitable for high current circuit connections that do not require frequent plugging. This type of connection has a number of contacts ranging from 2 to nearly 100, a rated current ranging from 1 to several hundred amperes, and a working voltage ranging from 300 to 500 volts.

(5) PCB connector

Printed board connectors are transitional from rectangular connectors and should belong to the category of rectangular connectors, but are generally listed separately as new connectors. The contact points range from one to dozens, and can be used with strip connectors or directly with circuit boards. They are widely used for connecting various boards and motherboards in computer hosts. For reliable connection, contacts are generally plated with gold to enhance their reliability, commonly known as gold fingers.

(6) Other connectors

Other connectors include integrated circuit sockets, power plug sockets, fiber optic connectors, ribbon cable connectors, etc.