What is a fuse, what is its effect?
Also known as the fuse fuse, IEC127 scale it is defined as "fuse (fuse-link)". It is a kind of electrical components, which is assembled in the circuit to ensure the safe operation of the circuit. The effect is: when the fuse circuit fault or abnormal, with current continuously reduced, but also reduce the current may damage the circuit in some tension devices or precious devices may also destroy the circuit and the formation of fire. If the circuit correctly settle the fuse, the fuse will be in the abnormal current reduced to certain height and must moment their fuse so as to cut off current, safe operation affect the protection circuit. The earliest fuse was created by Edison more than and 100 years ago, because then the industrial technology is not developed incandescent lamp is very valuable, in order to be, and finally it is used to cover the price of expensive incandescent lamp. What is the reason for the fuse?
As we all know, when the current flows through the conductor, there is a certain resistance to the conductor, so the conductor will have a fever. Have a fever and amount of follow this formula: Q=0.24I2RT; the Q is have a fever, 0.24 is a constant, I is the current flowing through the conductor, R is the resistance of a conductor, T is the current through the conductor time; so the formula we is not difficult to see the simple things that fuse.
When a fuse is made and its shape is determined, its resistance R is absolutely certain (if it does not consider its resistance temperature coefficient). When the current flows through it, it will have a fever, followed by the growth of its fever is also growing. The size of the current and the resistance rate of heat, structure and assembly state of the fuse to determine the rate of heat dissipation rate, if the rate of heat is less than the heat dissipation when the fuse is not fuse. If the rate of heat is the rate of dissipation of heat, it will not fuse in a long time. If the rate of heat is greater than the rate of dissipation of heat, the heat will be more and more. Also because it has a certain specific heat and quality, the growth of its heat on the temperature of the reduction of the temperature, when the temperature is reduced to the melting point of the fuse fuse will fuse. This is the fuse of the truth. It should be known from this point that you must seriously study the physical characteristics of the materials you choose and make sure they have the same number of dimensions when designing a fuse. Because of these factors on the fuse can be a cause of the disorder caused by the role of tension. In the same way, when you use it, you must correctly assemble it. How is the structure of the fuse? What are the functions? What is the request?
As ordinary fuse consists of three parts: one is melt department, it is the focus of the fuse, the fuse is played off current role, unified, unified specification of melt fuse, material to be identical, what would be the same size as small as possible, the resistance value and the same, the most important thing is to fuse the features of the same the two electrode is; there are two departments, on weekdays, it is the important components of melt and circuit connection, it must have good conductivity, the resistance of the assembly three is significant war; support department, fuse melt as ordinary are fine tender, support is firm and will affect the melt. The three departments become rigid all convenient assembly and application, it must have good mechanical strength, resistance, heat resistance and flame retardant insulation in the application should not happen, deformation, fracture and extinguish Short circuit phenomenon; fuse power circuits and high power equipment applications, not just as simple fuse three departments, and the arc assembly, because the fuse cover not only that circuit current is large, and the voltage when the melt fusing the two is also very high, often show melt has melted (the fuse and vaporized, but current) is not cut off, its reason is in a flash fuse in voltage and current under the arc signs between the two electrode fuse. The interrupter assembly must have insulation thermal conductivity and good strong, and negative charged. Quartz sand is commonly used for arc extinguishing data.
Else, some have to fuse fuse assembly, its action is when the fuse moves (fuse) after its surface must change, easy maintenance staff invention, for example: light color, solid pop indicator etc..