11 Basic Principles For Connector Selection

As one of the most commonly used equipment, you will encounter some difficulties during selecting connectors. If you can understand the basic principles of the following 11 connector selection in advance, it will be easier to find connectors that meet your requirements.

Ampacity

When selecting a connector for power signal, pay more attention to the current carrying capacity of the connector, adopt a derating design, and pay attention to the insulation withstand voltage between the pins.

Structure size

The external dimensions of the connector are very important. There are certain space limitations for connections in products, especially single-board connectors, which cannot interfere with other components. Choose the appropriate installation method according to the use space and installation position (installation includes front installation and rear installation, installation and fixing methods include rivets, screws, collars or quick locking of the connector itself, etc.) and shape (straight, curved, T type, round, square).

Impedance matching

Some signals have impedance requirements, especially RF signals, which have stricter impedance matching requirements. When the impedance does not match, it will cause signal reflection, which will affect the signal transmission. Generally, signal transmission has no special requirements on the impedance of the connector.

Shield

With the development of communication products, EMC has been paid more and more attention. The selected connector needs to have a metal shell, and the cable needs to have a shielding layer. The shielding layer should be connected with the metal shell of the connector to achieve the shielding effect. The injection molding method can also be used to wrap the plug part with copper skin, and the shielding layer of the cable and the copper skin are welded together.

Anti-misinsertion

There are two aspects to prevent mis-insertion: on the one hand, the connector itself, which rotates 180 degrees, and misaligned connection leads to wrong connection of signals. On the other hand, in order to reduce the types of materials, the same connectors are used for several signals. At this time, it is possible to insert the A plug into the B socket. At this time, you need to pay attention. If this happens, it will cause serious consequences ( When the alarm is not simple and destructive), the A and B interfaces must be selected as different types of sockets (for example, A is male, B is female).

Reliability

Connectors are used to connect signals, so the connection parts need more reliability. For example, surface contact is generally better than point contact, and pinhole type is better than leaf spring type.

Generality

In the selection process of connectors, general materials should be selected as much as possible, especially among products of the same series, the selection of connectors has strong versatility, reducing the types of materials, increasing the quantity, reducing costs, and reducing supply risks.

Use environment

When the connector is used in outdoor, indoor, high temperature, high humidity, salt spray, mold, cold and other environments, there are special requirements for the connectors.

Plugging frequency

The plugging and unplugging of the connector has a certain life. After the number of plugging and unplugging reaches the limit, the performance of the machine will decrease. When some signal interfaces need to be plugged and unplugged frequently, pay more attention to the plugging and unplugging times of the connector when selecting the connectors.

Live condition

Depending on whether it is often live or not, choose a pin or female connector.

Comprehensive consideration

In the process of selecting connectors, various factors are not independent and often interact with each other. Therefore, we must comprehensively consider in the process of connector selection and choose the most suitable connector. The selection will be different at different stages, which will directly affect the use of the product.

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