Connectors are used to connect two circuit boards or electronic devices for power or signal transmission. Understanding the classification of connectors helps us to buy better, because there are many types of connectors, common types include communication interface terminals, wiring terminals, wire-to-board connectors, board-to-board connectors, etc.
The classification of common connectors are:
1. Concentric connector
The concentric connector is a small plug-and-socket connector, which is characterized by its small size and its own switch function, which is suitable for low-frequency circuits.
2. Column connector
The number of leads of the bar-column connector is usually dozens or less, and it is often used to connect the printed circuit with the circuit of the device in the electronic equipment.
3. Printed circuit connectors
The role of printed circuit connectors is to be used to connect printed circuits in electrical or electronic equipment.
4. Ribbon Cable Connector
The socket of the ribbon cable connector can be directly welded on the printed circuit. Because the plug and the ribbon cable adopt the piercing and crimping technology, the advantages are reliable contact and convenient use, and are often used in the connection of instrumentation circuits.
5. Circular connector
Most of the plugs and sockets of circular connectors use screw connection technology, and their terminals range from 2 to hundreds of terminals. They are characterized by small size and high reliability, which can meet the needs of cable connection between electronic devices.
6. Rectangular Connector
The plug and socket of the rectangular connector adopts the threaded guide rod connection technology and is equipped with a locking device, which is often used for the electrical connection of electronic equipment, intelligent instruments and electronic control equipment.
7. Water pressure seal connector
Water pressure sealed connectors usually refer to circular connectors, which are often used for working circuit connections in underwater or harsh environments.
8. RF coaxial connector
RF coaxial connector is a small threaded locking connector, characterized by small size, light weight, easy operation, etc. It is often used to connect RF cables in radio equipment and high-frequency circuits, and the operating frequency is generally above 500MHz.
How to choose a connector?
1. Pins and spacing
The number of pins and pin spacing are the basic basis for connector selection. The number of pins chosen for the connector depends on the number of signals that need to be connected. During the welding process of the placement machine, due to the high temperature, the plastic of the connector will be deformed by heat, and the middle part will bulge, resulting in virtual welding of the pins.
At present, electronic equipment is developing towards miniaturization and precision, and the pin pitch of connectors has also changed from 2.54mm to 1.27mm to 0.5mm. The smaller the pin pitch, the higher the production process requirements.
2. Electrical performance
The electrical properties of the connector mainly include: limiting current, contact resistance, insulation resistance and electric strength. When connecting a high-power power supply, pay attention to the limiting current of the connector; when transmitting high-frequency signals such as LVDS, PCIe, etc., pay attention to the contact resistance. Connectors should have low and constant contact resistance, typically tens of mΩ to hundreds of mΩ.
3. Environmental performance
The environmental performance of the connector mainly includes: temperature resistance, humidity resistance, salt spray resistance, vibration, shock, etc. Choose according to the specific application environment. If the application environment is relatively humid, the requirements for the connector's moisture resistance and salt spray resistance are high, so as to prevent the metal contacts of the connector from being corroded. In the field of industrial control, the requirements for the anti-vibration and shock performance of the connector are high, so as to prevent the connector from falling off during the vibration process.
4. Mechanical properties
The mechanical properties of the connector include plugging force, mechanical foolproofness, etc. Mechanical foolproofing is very important to the connector. Once inserted reversely, it is likely to cause irreversible damage to the circuit. You must pay attention to this.
Through the connector, the circuit can be modularized, the assembly process of the electronic product can be simplified, and the product can be easily maintained and upgraded. For modular circuits, the purchase and selection of connectors play a pivotal role.
