Three basic properties of connectors

• 时间：2016-11-11 15:58 点击：

• The basic performance of the connector can be divided into three categories: mechanical, electrical and environmental performance. 1．Mechanical properties on the connection function, the insertion force is an important mechanical properties. Insertion force is divided into insertion force and pull out the output (also called separation force), both of the requirements are different. In the relevant standard has the maximum insertion force and the minimum separation force, which indicates that, from the perspective of use, the insertion force to small (and thus have low insertion force LIF and insertion force of the structure of ZIF), and if the separation force is too small, it will affect the contact reliability.  Another important mechanical property is the mechanical life of the connector. Mechanical life is actually a kind of durability (durability) index, in the national standard GB5095 it is called the mechanical operation. It is based on an insert and a pull out for a cycle, in order to complete the requirements of the plug and pull loop connector can normally complete the connection function (such as the contact resistance value) as a basis for judging.  The insertion force and mechanical life of the connector are related to the coating quality (sliding friction coefficient) of the contact area and the contact element arrangement size precision (alignment degree). 2．The main electrical properties of electrical performance connectors include contact resistance, insulation resistance and electrical strength. ① An electrical connector with high quality of contact resistance shall have a low and stable contact resistance. The contact resistance of the connector ranges from a few to several tens of cents. ② To measure the insulation resistance of the insulation performance index between electrical connector contacts and contact with the shell, the order of the number of megabytes to several begohm ranging from europe. ③ Resistance to electrical strength, or voltage resistance, dielectric pressure, is the characterization of the connector between the contact or contact parts and the resistance between the enclosure test voltage capacity. ④ Other electrical properties.  Electromagnetic interference leakage attenuation is the evaluation of the electromagnetic interference shielding effect of connectors, electromagnetic interference leakage attenuation is to evaluate the effect of the electromagnetic interference connector, generally in the 100MHz~10GHz frequency range test.  On the radio frequency coaxial connectors, there are characteristic impedance, insertion loss, reflection coefficient, voltage in Bobbi (VSWR) and other electrical indicators. Due to the development of digital technology, in order to connect and transmit high-speed digital pulse signal, a new type of connector is high speed signal connector, the corresponding, in terms of electrical performance, in addition to the characteristic impedance, there are some new electrical indicators, such as crosstalk (crosstalk), transmission delay, delay (skew (delay) etc.). 3．Common environmental performance, including temperature, humidity, salt spray, vibration and impact, etc.. ① At present, the maximum operating temperature of the connector is 200 degrees C (except for a few high temperature special connector), the lowest temperature is -65. The operation of the connector, the current heat generated in the contact point, resulting in a temperature rise, so that the working temperature should be equal to the ambient temperature and the temperature rise and contact. In some codes, the maximum temperature rise of the connector in the rated operating current is clearly defined. ② Wet moisture intrusion will affect the connection of H insulation and corrosion of metal parts. Constant humidity test conditions for the relative humidity 90%~95% (according to the product specification, up to 98%), temperature +40 + 20 degrees Celsius, the test time according to product requirements, at least 96 hours. Alternating damp heat test is more stringent. ③ Salt fog connector in the presence of moisture and salinity conditions, the metal structure, the contact surface treatment layer may cause galvanic corrosion, affect the physical and electrical properties of connectors. In order to evaluate the ability of electrical connector to withstand the environment, the salt spray test. The connector is suspended in a temperature controlled test chamber, with a specified concentration of Sodium Chloride Solution with compressed air emitted, forming a salt mist atmosphere, the exposure time of the product specification, at least 48 hours. ④ Vibration and shock resistance to vibration and impact is an important performance of the electric connector, in special application environment such as particularly important aviation and aerospace, railway and highway transportation, it is an important index of robustness and reliability of electrical contact test of the mechanical structure of the electric connector. There are clear provisions in the relevant test methods. The peak acceleration, duration and pulse waveform, and the time of electrical continuity interruption should be specified in the impact test. ⑤ Other environmental performance in accordance with the requirements of the use of electrical connectors, the other environmental performance is also sealed (air leakage, liquid pressure), liquid impregnation (for a specific liquid resistance to the bad), low pressure, etc..