18gay男同69亚洲帅男蓝宇,免费在线 观看av电影,学生妹逼逼网站,欧美日韩一区久久久久久

The basic performance of connectors can be categorized into three major types: mechanical performance, electrical performance, and environmental performance.

1.In terms of connection function, the plug-in and pull-out force is an important mechanical performance. The plug-in and pull-out force is divided into the insertion force and the extraction force (also known as the separation force), and the requirements for the two are different. There are regulations on the maximum insertion force and the minimum separation force in the relevant standards, which shows that from the perspective of use, the insertion force should be small (thus there are low insertion force (LIF) and zero insertion force (ZIF) structures), and if the separation force is too small, it will affect the reliability of the contact.

Another important mechanical performance is the mechanical life of the connector. Mechanical life is essentially a durability indicator, referred to as "mechanical operation" in the national standard GB5095. It is defined as one cycle consisting of one insertion and one extraction, and the ability of the connector to normally perform its connection function (such as contact resistance value) after a specified number of plug-in and pull-out cycles is used as the basis for evaluation.

The plug-in and pull-out force and the mechanical life of a connector are related to the structure of the contact (the magnitude of the normal force), the quality of the plating at the contact area (the coefficient of friction), and the dimensional accuracy of the contact arrangement (alignment).

2.The main electrical performance aspects of a connector include contact resistance, insulation resistance, and electrical strength.

2.1Contact Resistance:A high-quality electrical connector should have low and stable contact resistance. The contact resistance of a connector ranges from a few milliohms to tens of milliohms.

2.2Insulation Resistance: This is an index to measure the insulation performance between the contact parts of an electrical connector and between the contact parts and the housing, ranging from hundreds of megaohms to thousands of megaohms.

3.Electrical Strength: Also known as voltage endurance or dielectric withstand voltage, it characterizes the ability of the connector's contact parts to withstand the rated test voltage between each other or between the contact parts and the housing.

4.Other Electrical Performance

Electromagnetic interference leakage attenuation is an evaluation of the connector's electromagnetic interference shielding effect, which is generally tested in the frequency range of 100MHz to 10GHz.

For radio frequency coaxial connectors, there are also electrical indicators such as characteristic impedance, insertion loss, reflection coefficient, and voltage standing wave ratio (VSWR). With the development of digital technology, a new type of connector called high-speed signal connector has emerged to connect and transmit high-speed digital pulse signals. Accordingly, in terms of electrical performance, in addition to characteristic impedance, some new electrical indicators have also emerged, such as crosstalk, transmission delay, and skew.

5.Common environmental performance aspects include temperature resistance, humidity resistance, salt fog resistance, vibration, and shock.

The maximum working temperature for current connectors is 200℃ (excluding a few high-temperature special connectors), and the minimum temperature is -65℃. Since current generates heat at the contact points when a connector is in operation, causing a temperature rise, the working temperature is generally considered to be the sum of the ambient temperature and the contact point temperature rise. Some specifications clearly define the maximum allowable temperature rise for connectors under rated working current.

The intrusion of moisture can affect the insulation performance of connectors and cause rust on metal parts. The conditions for a constant damp heat test are a relative humidity of 90% to 95% (up to 98% according to product specifications) and a temperature of +40±2℃, with the test duration specified by the product, a minimum of 96 hours. The alternating damp heat test is even more stringent.

When connectors work in an environment containing moisture and salt, their metal structural parts and contact surface treatment layers may undergo electrochemical corrosion, which can affect the physical and electrical performance of the connectors.