The basic performance of rj45 connectors can be divided into three categories: mechanical performance, electrical performance and environmental performance.
1. Mechanical properties As far as the function of rj45 connector is concerned, the insertion and extraction force is an important mechanical property. Plug-in force is divided into insertion force and extraction force (pull-out force is also called separation force), and the requirements of 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 structures with low insertion force LIF and no insertion force ZIF), and if the separation force is too small, It will affect the reliability of the contact.
Another important mechanical property is the mechanical life of the connector. Mechanical life is actually a durability indicator, which is called mechanical operation in the national standard GB5095. It takes one insertion and one extraction as a cycle, and is judged based on whether the connector can normally complete its rj45 connector function (such as contact resistance value) after the specified insertion and extraction cycle.
The insertion and extraction force and mechanical life of the rj45 connector are related to the contact structure (positive pressure), the coating quality of the contact part (sliding friction coefficient) and the dimensional accuracy of the contact arrangement (alignment).
2. Electrical properties The main electrical properties of the connector include contact resistance, insulation resistance and electrical strength.
① Contact resistance A high-quality electrical connector should have low and stable contact resistance. The contact resistance of connectors varies from a few milliohms to tens of milliohms.
② Insulation resistance is an index that measures the insulation performance between the contacts of an electrical connector and between the contacts and the shell. Its order of magnitude ranges from hundreds of megohms to thousands of megohms.
③ Electrical strength, also known as withstand voltage and dielectric withstand voltage, represents the ability to withstand the rated test voltage between the connector contacts or between the contacts and the shell.
④ Other electrical properties. Electromagnetic interference leakage attenuation is to evaluate the electromagnetic interference shielding effect of the connector. Electromagnetic interference leakage attenuation is to evaluate the electromagnetic interference shielding effect of the connector. It is generally tested in the frequency range of 100MHz-10GHz. For RF coaxial connectors, there are also electrical indicators such as characteristic impedance, insertion loss, reflection coefficient, and voltage standing wave ratio (VSWR). Due to the development of digital technology, in order to connect and transmit high-speed digital pulse signals, a new type of connector, namely a high-speed signal connector, has emerged. Correspondingly, in terms of electrical performance, in addition to characteristic impedance, some new electrical indicators have also emerged. , such as crosstalk, transmission delay, skew, etc.
3. Environmental performance Common environmental performance includes temperature resistance, moisture resistance, salt spray resistance, vibration and impact resistance, etc.
① Temperature resistance The current maximum operating temperature of the connector is 200℃ (except for a few high-temperature special connectors), and the minimum temperature is -65℃. Because when the rj45 connector is working, the current generates heat at the contact point, causing a temperature rise. Therefore, it is generally believed that the operating temperature should be equal to the sum of the ambient temperature and the temperature rise of the contact. In some specifications, the maximum allowable temperature rise of the connector under the rated operating current is clearly specified.
② Resistance to moisture intrusion will affect the insulation performance of the connection and corrode metal parts. The constant humidity and heat test conditions are relative humidity 90-95 (according to product specifications, up to 98), temperature 40±20℃, and the test time is according to product regulations, which is at least 96 hours. The alternating heat and humidity test is more stringent.
③ Salt spray resistance When the rj45 connector works in an environment containing moisture and salt, the surface treatment layer of its metal structural parts and contacts may cause galvanic corrosion, affecting the physical and electrical properties of the connector. In order to evaluate the ability of electrical connectors to withstand this environment, the salt spray test is specified. It hangs the connector in a temperature-controlled test chamber and sprays sodium chloride solution with a specified concentration with compressed air to form a salt spray atmosphere. The exposure time is specified by the product specification, which is at least 48 hours.
④ Vibration and impact resistance Vibration and impact resistance are important properties of electrical connectors. They are particularly important in special application environments such as aviation and aerospace, railways and road transportation. It is an important part of inspecting the mechanical structure of electrical connectors. An important indicator of the robustness and reliability of electrical contacts. There are clear regulations in the relevant test methods. The peak acceleration, duration and shock pulse waveform, as well as the time for interruption of electrical continuity should be specified in the impact test.
⑤ Other environmental properties According to the usage requirements, other environmental properties of electrical connectors include sealing (air leakage, liquid pressure), liquid immersion (resistance to specific liquids), low air pressure, etc. .
Desso Hardware Electronics, as a professional connector manufacturer, has been focusing on the production, development and sales of radio frequency connectors for thirteen years. It has accumulated rich technical experience and strong strength. Now it is connected nationwide It has gained a good reputation in the appliance market, and through cooperation with Renhao's foreign trade team, the products have been sold to more than 40 countries and regions at home and abroad. Official website address: / Main products: rj45 connector, rj45 interface, waterproof connector, etc. Welcome to purchase!