Today's industrial systems contain a large number of electrical components and devices, from  PCB  circuit boards and sensors to drives and motors to industrial computers, electrical cabinets, and even production lines and machines They usually need to be connected to each other to work together. In this process, the various types of industrial connectors actually play a very important role.

Do not underestimate the industrial connector, despite its small size, but it contains the technology itself is not simple. On the one hand, the reliability of the electrical connection directly determines the performance of the equipment system. On the other hand, in the face of different types of application scenarios, the classification of industrial connectors is also extremely complex.

I Definition and classification of industrial connectors

First of all, we start with the definition of the industrial connector and its classification and talk about the basic rules of connector product model naming.

1. According to the function of electronic devices connected inside and outside, the level of interconnection is divided into six layers

Layer 1: the interconnection of components to the package.

Layer 2: package to board interconnection.

Layer 3: board-to-board interconnection.

Layer 4: component-to-component interconnection.

Layer 5: the component-to-component interconnection of input and output interfaces.

Layer 6: system-to-system interconnection.

Connector in accordance with the structure classification diagram

2. According to the structure

• Board-to-board connectors

• Board-to-wire connectors

• Wire-to-wire connectors

3. According to the power

• Power connectors (transmitting power)

• Signal connectors (transmitting signals)

• High-frequency connectors (transmit data)

4. According to the shape

• Circular connectors, are mostly used in military equipment.

• Rectangular connectors, a wide range of uses and rapid development.

So in summary, taking into account the technical development of the connector and the application of the industry, with reference to relevant technical standards, the connector can be divided into five categories.

• Rectangular connectors

• Circular connectors

• Radio frequency connectors

• Fiber optic connectors

• Non-contact connectors (such as proximity switches, etc.)

Any electrical system must transmit a current as a carrier of signal or energy, from one conductor through the contact between the conductor and the conductor to another. This contact between conductor and conductor is called electrical contact, and the completion of this electrical contact task is the connector. It will cover the "power", "signal", and "data".

The industrial connector is to assume the role of current or signal connection "bridge". Although it is only a component, it plays a vital role.

There is no unified connector classification standard. The new application sector has emerged, the structure is growing, and it is difficult to classify and name a fixed pattern. Despite this, some basic classification principles are still valid, let's first understand the prerequisites for the connector classification, 

The above gives you the classification of connector products, you can easily remember. And if users want to further understand the connector products, you need to master the naming of its product model, that is, the order number.

The naming of model numbers is the foundation for user purchase and connector manufacturers' production planning. Two principles govern the connection business as a whole.

The first is a letter code followed by a number, with the goal of reflecting all or most of the product's structural qualities in the model nomenclature. The benefit is that the model number is easy to recognize. The downside is that the model number may be longer and more complex. With the trend of connection shrinkage, the space available for printing code is shrinking, making printing code printing more difficult.

The second option is to use a combination of pure Arabic numerals. The advantages of this method are that it is straightforward, manageable, and easy to print.

It can be expected that these two ways will co-exist for a long time, and continue to enrich and develop.

Connectors are a common part of almost any electronics project. Understanding the connector selection process and what to look for in the selection process becomes very important in the design process.

II How to select industrial connectors?

Connector selection process

The industrial connector selection process generally requires the following process.

1, the institution engineer to confirm the mechanical characteristics of the connector (temperature, humidity and corrosion resistance);

2, hardware engineers to calculate the ability of the connector over current;

3, to confirm whether multiple connectors can be dummy-proof, to prevent the selection of different connectors to choose the same model;

4, hardware confirm the signal and power from different connectors to go, whether there will be a connector overhang module internal chip damage;

5, to determine the order of the arrangement of the male pins;

6, after the software conversion to determine the order of the arrangement of the female headers;

7, after the conversion is complete, carefully check whether the circuit board and harness connection is correct.

In the above process, special attention should be paid to the following areas

1 In the design process, you need to pay attention to doing the order of pins when the definition of the order to be consistent. (Double row of pins are more prone to errors, because there are two different ways of counting cycles and counting up and down)

2 After the completion of the creation, the hardware engineer must be confirmed with the engineer who built the library.

3 Certain shapes and drawings need to be carefully confirmed (the ordinary docking socket is more likely to analyze the order)

4 If it is not an ordinary docking socket, you need to pay attention to: The view must be confirmed that it is from top to bottom, or look at it. In the case of two views, the engineers who are doing harness will carefully pay attention to the mother's head, and the engineers who do the printed circuit board will pay attention to the public, because there are two, so it is not easy to make mistakes. For other cases, if the mete is used with a pin, use the outer casing to form a housing, it is necessary to note that the needle is not in the direction. The work of the establishment of the library can only be successfully completed only from the order of the mother head to the public.

14 things must be considered in the connector selection

Commonly used industrial connector types are relatively wide, which have 12 major categories. Despite the many types, it is necessary to follow the selection of the following 14 points, including the main flow, impedance matching, shielding, versatility, cost, availability, and other fourteen criteria.

1. Flow rate: When selecting a connector of the power signal, it is more concerned about the traffic of the connector. We have to use a drop-down design while paying attention to the insulation withstand voltage between the pins.

2. Structure size: The outer dimensions of the connector are very important, and there is a certain spatial limit in the product, especially on a single board, and cannot interfere with other components. Depending on the space of use, the installation site selects the appropriate installation method and shape (straight, bend, T type, circular, square).

3. Impedance matching: Some signals have impedance requirements, especially radio frequency signals, which are more stringent for impedance matching requirements, and the impedance mismatch can cause signal reflection, which affects signal transmission. General signal transmission does not have special requirements for the impedance of the connector.

4. Shielding: With the development of communications products, EMC is increasingly valued. When the selected connector is required, there is a metal case while the cable requires a shield. The shield is to be connected to the metal housing of the connector to achieve the shield. It is also possible to use the injection molding method to wrap the plug site, and the shield of the cable is welded to the copper skin.

5. Anti-mistake plug: First, the connector itself rotates 180 degrees, misplaced error connection caused signal error connection. At this point, pay attention to selecting the anti-wrong plug connector as much as possible. Or we can ensure that the connector is the relative positional relationship to ensure assembly is Unique; on the other hand, several signals use the same connector for reducing the type of material. At this time, it may appear on the plug to the B plug. At this time, it is necessary to pay attention, if so, it will be caused When severe consequences, the A and B interface must be selected as different types of sockets.

6. Reliability: The connector is used to connect the signal, so the connecting portion is reliable (eg, the surface contact is better than point contact, the pinhole is superior to the fluffy, etc.).

7. Versatility: Select a universal object as possible during the selection process of the connector, especially between the same series. The selection of the connector has strong versatility, reducing the type of material, increasing the number reduction cost while reducing the supply risk.

8. Usage: Connectors use special requirements for connectors when using environmental, salt, mold, cold, etc.

9. Locking function: When it occurs when the connector is released, the connector is required to have a lock function.

10. Cost: Cost is also a more important factor in the selection process. As the market competition is increasingly fierce, the appropriate selection of connectors, the self-cost of the connector, and processing costs require comprehensive consideration.

11. Availability: The supply of the connector is affected by many factors. For example, a general connector is better than an uncommon connector.

12. Plugging frequency: The connector has a certain life. After the number of plugs reaches the limit, the performance of the connector will decline.

13. Pluspective: Depending on whether or not the charged or not, select a needle or aperture type connector.

14. Comprehensive consideration: In the process of selecting the connector, it is not independent and often interacts. Therefore, we should consider it in the connector selection process, choose the most suitable connectors, and the choice of quality will affect the product varying degrees at different stages.