automotive blade fuse specification.smd chip fuse

　　Why sometimes patch type fuses become highly resistant and we know that the operating principle of tubular fuses is: overcurrent causes the thermal balance on the melt to be disrupted, and when the melt temperature rises to the melting point of the metal material, the middle part of the melt changes from solid to liquid. Due to the surface tension and gravity of the metal material suspended in the tube, the liquid part of the melt pulls away from both ends and drops downwards, The flashover caused by voltage causes the melt temperature to continue to rise, further flashover and further widening the distance until the circuit is completely cut off. For patch type fuses, their operating principle is the same. However, due to different structural states, the surrounding of the metal melt is tightly surrounded by the polymer or ceramic materials of its matrix. Even the melted metal cannot contract towards both ends and can only rely on diffusion, infiltration, or absorption towards the surrounding materials. If the overcurrent disappears during this process (such as instantaneous pulse phenomenon), The process of diffusion or absorption is still in progress, which will result in an increase in resistance and incomplete melting of the melt. Let's take a look at the consequences of this phenomenon again: because the overcurrent has disappeared at this time and has not caused any adverse effects on the circuit, although the fuse has not been completely blown at this time, the capacity of the melt has weakened, and when subjected to overcurrent again, it will be blown quickly, ensuring the protective effect on the circuit; If the second overcurrent is still an instantaneous pulse, it will cause the resistance to increase again but still not fully fuse, and the capacity of the melt will also weaken again; In short, the phenomenon of Shenzhen SMD fuse with increased resistance and incomplete blown does not affect its protective function for the circuit. As long as the overcurrent lasts for a long time, it will be completely blown. On the contrary, if there is no change after experiencing overcurrent, there may be a problem with the protective function of the fuse. Compared with tubular fuses, the melt of slow break fuses is composed of two or more metal materials, and there is also a process of diffusion and infiltration between different materials when subjected to overcurrent. Therefore, it has the ability to withstand pulses and has the opportunity to increase resistance.

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