1. According to the function of connecting the inside and outside of the electronic device, the level of interconnection is divided into 6 layers:

      Layer 1: Interconnection of components to packages;

      Layer 2: the interconnection of packages to the circuit board;

      Layer 3: the interconnection of plates to plates;

      Layer 4: Interconnection of components to components;

      Level 5: The interconnection of components to the input and output interfaces;

      Layer 6: System-to-system interconnection.

*Device connector example

2. Categorize by structure:

      A. board-to-board connectors;

      B. board-to-wire connectors;

      C. Wire-to-wire connectors.

*Connectors are illustrated according to structural classification

3. Classification by Power:

     A. Power connector (transmitting power);

     B. signal connectors (transmitting signals);

     C. High-frequency connectors (transmit data).

*Connectors are illustrated by power classification

4. Classification by shape:

     A. circular connectors, mostly used in military equipment;

    B. Rectangular connectors, which are versatile and rapidly developing

    C. Now, modular connectors are the shining "stars" in the heavy-duty connector family.

 *Circular and rectangular connectors (combination type)

        Therefore, considering the technological development of connectors and the application of the industry, with reference to relevant technical standards,

 connectors can also be divided into five categories:

• Rectangular connectors;

• circular connectors;

• RF connectors;

• fiber optic connectors;

• Non-contact connectors (e.g. proximity switches, etc.).

            In order to let you know how to choose the right connector, the following will introduce you to the selection of industrial connector products.

        Product model naming is the basis for user procurement and connector manufacturer organization production. Throughout the connector industry,

 it follows two principles:

        The first is the way of alphabet code plus numbers, and strives to reflect all or the main structural characteristics of the product in the model naming. 

The benefit is that it 

is easy to identify; The  disadvantage is that the model may be longer and more complex; With the trend of connector miniaturization, the space that can be coded is 

getting smaller 

and smaller, and inkjet printing isbecoming more and more difficult.

        The second is a combination of pure Arabic numerals, which has the advantage of being concise and easy to manage and print.

        These two ways will coexist for a long time and continue to enrich and develop.

        As an important interface for data, signal, and power supply, connectors should fully consider all aspects of the application environment when selecting

 connectors.

        In the actual operation process, if the principles of connector selection are not deeply understood, the procurement process often becomes "simple and

 crude".

        For example, when it comes to choosing gold needles or silver needles, it is often simply thought that gold needles should be chosen for high 

considerations of appearance,

and silver needles should be chosen with tight budgets. Is that enough? Obviously not. Because gold plating or silver plating, in addition to the difference in 

cost, 

it is more important to consider the original needs. For example, when the electrical parameters require 5V and 5mA, only gold needles can be used.

        Understanding and expressing your needs is a prerequisite for the correct selection of connector parts. Whether it needs to be waterproof, 

whether it is with or without grounding shielding, whether to choose stamping needles or burs, etc., these must be known before the start of procurement, 

and these issues will also be the key to affecting the price.

        About a decade ago, connector selection was primarily handled by mechanical engineers. They have to consider the layout of the entire system, 

and the selection of connectors is more about choosing the size and matching. As systems and equipment become smaller and electrical interference

 becomes more severe, 

new connector designs must take into account both mechanical and electrical performance. Connector selection now requires more complex considerations.

        Comparing prices, looking at size, and considering signal integrity, I have to say that the selection of connectors is really a technical job.

        First of all, if the needs are clear, then it is very simple, that is, "look".

        If there is such a picture, how should we determine the model?

• If you don't know the connector at all, then find the technician of the connector manufacturer you often contact, let him look at the picture and talk, 

find the connector in the photo, and provide the product model list.

• If you know a lot about connectors, open the official website of the target manufacturer, and you can usually complete most of the selection. 

If you are not sure about your judgment, you can consider the previous step and find a contact person on their official website to ask directly.

        However, many times, we are not particularly clear about the specific application requirements, so we need to understand our needs and 

express them clearly through "asking", 

which is the prerequisite for the correct selection of connector components.

        In order to reduce communication costs, we often need to ask the above "7 questions" when selecting connectors, interrogate the original needs, 

and clarify the selection ideas.

        A typical heavy-duty connector consists of the following:

        The same is 250V, 10A, within 15 wires, 10A or 6B can meet the requirements. A series or B series, just a difference in mounting size.

        All products are divided into two categories according to the mounting cutout size: A size and B size. There is no substantial difference between A and B,

 but as there are more and more types of connectors, classification becomes more and more important. The A series is smaller (typical fixing hole spacing is

 17.5mm, 

except for 3A), and there are models such as 3A, 10A, 16A, 32A (two 16A discharged side by side), etc.; The B series is larger (typical fixed hole spacing is

 32mm) 

and is available in 6B, 10B, 16B, 24B, 32B (two 16Bs in parallel) and 48B (two 24B in parallel) models.

        If you need to upgrade for the future or consider reserving a line, then 6B is the first choice. Because the size difference is not large, it can 

accommodate up 

to 24 cores. In addition, if you consider a mix of different requirements such as signal, power, airway, etc., then the B-series is the only choice, as the module 

product ferrule can only be used in the B-series housing.

        Regarding the connection methods of connectors, it is pointed out that the six connection methods are bolted connection, crimp connection, 

cage shrapnel connection, coaxial bolt connection, HARAX connection, quick installation connection and wire wound connection. These connection

 methods have their own advantages and disadvantages, and which one meets the requirements needs to be considered in combination with the 

application scenario and budget.

        The chart above is a simple and crude price comparison:

        According to the requirements, the following set of connectors may be selected▼

        After the first 7 questions are answered correctly, you can select the corresponding model for the following parts:

        However, connector types vary widely, and the above 7 questions cannot apply to all connectors. For example, for the M12 

series connectors in the figure below, we need to have another set of selection ideas.

        Traditional M12 connectors are screwed together, making installation time-consuming and labor-intensive. To enhance the ease of use of 

M12 connectors while balancing reliability and affordability, PushPull M12 connectors are available under the standard number IEC61076-2.

        According to a reliable installation timing test from users, installing an M12 node takes an average of 22.5 seconds less than the screw-connected 

version using the push-pull version,saving 5.25 hours if the number of installations reaches 1000, and about 625 hours or 26 days when the number 

of installations reaches 100,000.Multiply the labor hours to save costs, 

because the economic benefits brought by small changes in installation methods are clear at a glance.

        The vast majority of connector selection can be completed by "looking" and "asking" above. However, if there are still doubts and 

uncertainties after these steps, it is necessary to have in-depth communication and communication with professional connector manufacturers 

to obtain their assistance and support in these aspects.

        From the economic and long-term perspective of the project, price is never the first consideration, but also need to consider the technical 

requirements of the connectorproduct and the projectconstruction schedule, overall and long-term planning considerations to ensure that the 

performance and overall size of the connector product can be optimal.

        After the above description, I wonder if you already know the classification, selection and application of connectors? The selection of industrial 

connectors is a technical activity and often encounters various problems. If you have any questions in this regard, please feel free to contact us.

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