RJ45 connectors affect pin pin pin and current factors

　　The contact resistance of PIN PIN PIN is mainly affected by contact material, vertical pressure, surface morphology, applied voltage and current.

 　1) surface morphology

　　The surface morphology includes the design shape and the environmental state, the contact surface may be due to dust, rosin, oil on the contact surface mechanical deposition of loose surface film, the contact area is reduced, the contact resistance is increased and the contact resistance is extremely unstable because of the micro-pits on the contact surface. Second, the fouling film formed by physical adsorption and chemical adsorption is mainly chemical adsorption on metal surface, which is produced by electron migration after physical adsorption. Therefore, for some products requiring high reliability, such as electrical connectors for aerospace applications, it is necessary to have clean assembly and production environment conditions, perfect cleaning process and necessary structural sealing measures, the user must have good conditions for storage and operation.

　　2) use voltage

　　When the applied voltage reaches a certain threshold, the film of the contact parts will break down, and the contact resistance will decrease rapidly. However, the thermal effect accelerates the chemical reaction in the vicinity of the film and has a certain repair effect on the film. So the resistance is nonlinear. Near the threshold voltage, small fluctuations in the voltage drop can cause currents to vary in a range of twenty or dozens of times. Make the contact resistance change a lot, do not understand this situation will be in the test and use of contact errors.

　　3) contact material

　　The technical conditions of electrical connectors for different materials made of the same specification plug-in contact, the provisions of different contact resistance assessment index. Gjb101-86, general specification for fast detachable environment-resistant electrical connectors, contact resistance of 1mm diameter insert contacts, copper alloy ≤5m ω, iron alloy ≤15m ω.

　　4) the surface vertical pressure of the contact surface

　　The vertical pressure on the surface of a contact is the force generated by the surfaces in contact with each other and perpendicular to the contact surface. With the increase of vertical pressure, the number and area of contact micro-points increase gradually, and the contact micro-points transition from elastic deformation to plastic deformation. The contact resistance decreases as the concentration resistance decreases. The positive contact pressure mainly depends on the geometry and material properties of the contact parts.