The basic performance of terminals
Datetime: 2019-12-12 Visit: 468
Terminals as an important part of the electrical connection, within the scope of the connector. It is required to have the terminals of the basic properties of the connector have the basic performance is the same. Connector (Connector), the country also known as connectors, plugs and sockets. Generally refers to the electrical connector. I.e., the two active devices connected to the device, or the current transmission signal. Its role is very simple: in between the circuit is blocked at the barrier or isolated circuits, bridge the communication gap, so that the current flow, the circuit to achieve a predetermined function.The basic properties of the terminal block are mainly mechanical, electrical and environmental performance.First, the electrical performanceTerminal as the connector, which is the primary performance of electrical properties, electrical properties including: contact resistance, insulation resistance and dielectric strength.1. The contact resistance. Quality electrical connectors should have a low and stable contact resistance. Contact resistance of terminals from a few milliohms to tens of milliohms range.2. The insulation resistance. Performance indicators to measure the insulation between the contact terminals and contact with the housing, on the order of several hundred to several thousand megohms megohms range.3. The dielectric strength. Also known as resistance, voltage, dielectric strength is the ability to withstand the contact between characterization of terminals or contacts with the housing member rated test voltage.Second, the mechanical propertiesMechanical properties include insertion force connectors and mechanical life. Plug into force insertion force and withdrawal force (pull-out strength also known as separation force), the two requirements are different. There are standards in the maximum insertion force and the predetermined minimum separation force, this indicates that, from the point of view of use, smaller insertion force (LIF thereby low insertion force and insertion force ZIF no structure), while if the separation force is too small, it will affect the contact reliability; mechanical life is actually a durability (durability) indicators in the national standard GB5095 it called mechanical operation. It is the first time you insert and pull out of a cycle to cycle after a predetermined plug terminals can normally complete its connectivity features (such as contact resistance value) as the basis for evaluation.Terminals insertion force and mechanical life of the contact structure (positive pressure size) contact with the coating quality parts (sliding friction coefficient) and the dimensional accuracy of contact arrangement (aligned degrees) related.Third, environmental performanceCommon environmental performance include: temperature, humidity, salt fog, vibration, and shock.1. Temperature. At present, I produced the maximum operating temperature of the unit terminals is 120 ℃, the lowest temperature of -40 ℃. Since the connector is working, the current generates heat at the contact points, a temperature rise, it is generally considered to be equal to the ambient temperature and the temperature rise of the junction and. In some specifications, the connector specified the maximum temperature rise at rated operating current permissible.2. moisture. Intrusion of moisture will affect the terminals insulation and corrosion of metal parts. Damp heat test conditions for a relative humidity of 90% to 95% (based on product specifications, up to 98%), the temperature of + 40 ± 20 ℃, according to the specified test time, a minimum of 96 hours. Damp heat test is more stringent.3. resistant to salt spray. When the terminals in environments with moisture and salt, which metal structure, the contact surface treatment layer may produce galvanic corrosion, affecting the physical and electrical properties of terminals. In order to evaluate the electrical connector tolerate the capacity of the environment, set the salt spray test. It is suspended in the temperature controlled terminals of the test chamber, with compressed air ejection with a predetermined concentration of sodium chloride solution to form a salt spray atmosphere, exposure time is defined by the product specifications, at least 48 hours.4. Vibration and Shock. Vibration and shock resistance are important properties of terminals, such as aviation and aerospace, rail and road transport is particularly important in a specific application, it is the test robustness and electrical terminals of the mechanical structure of an important indicator of the reliability of the contact. In the relevant test methods are clearly defined. Impact test shall be provided that the peak acceleration, duration and impact of pulse shape, and electrical discontinuity of time.5. Other environmental performance. According to requirements, as well as other environmental sealing performance, liquid impregnation (abuse-resistant capabilities of a particular liquid) terminals, low air pressure.