1. When operating at a normal operating current of 25 ℃, the current rating of the fuse should usually be reduced by 25% to avoid harmful blowing. Most traditional fuses use materials with lower melting temperatures. Therefore, this type of fuse is relatively sensitive to changes in ambient temperature. For example, a fuse with a current rating of 10A is usually not recommended to operate at an ambient temperature of 25 ℃ and a current greater than 7.5A. 2. The voltage rating of the fuse must be equal to or greater than the effective circuit voltage. The general standard voltage rating series are 32V, 125V, 250V, and 600V. 3. The resistance of a resistor fuse is not important in the entire circuit. Since the resistance of a fuse with an amperage less than 1 is only a few ohms, this problem should be considered when using a fuse in a low-voltage circuit. Most fuses are made of materials with a positive temperature coefficient, so there are two types of resistors: cold resistance a
intelligent For most asynchronous rectifier boost switching converters that use inductors, there is a DC path between the input and output. The existence of this path can have two adverse consequences: firstly, once the output short circuit or severe overload time exceeds a few hundred milliseconds, it will cause the diode (usually Schottky diode) to overheat and damage; Secondly, when for some reason, such as human shutdown, the switching oscillation circuit stops working, and there is still voltage at the load end, which is only one diode lower than the input voltage drop, the output will still consume energy. In addition, if the residual voltage is lower than the steady-state operating voltage range of the load, it will put the circuit in an uncertain state. For applications where the output current is relatively small (less than 5A), using a single-chip current mode controller and high-end current sampling technology can effectively solve both of the above problems. In these
The fuses used in power circuits and high-power equipment not only have the three parts of a general fuse, but also have arc extinguishing devices. This type of fuse not only protects the circuit with a high working current, but also has a high voltage at both ends when the melt melts. Often, the melt has melted (melted) or even vaporized, but the current is not cut off, The reason is that at the moment of fusing, under the action of voltage and current, an arc pulling phenomenon occurs between the two electrodes of the fuse. This arc extinguishing device must have strong insulation and good thermal conductivity, and be negatively charged. Quartz sand is a commonly used arc extinguishing material. Fusing device In addition, some fuses have a blown indicator device, which is used to indicate that when the fuse is activated (blown), its appearance changes to a certain extent, making it easy for maintenance personnel to detect, such as emitting light, discoloring, and popping up sol
A general fuse consists of three parts: one is the melt part, which is the core of the fuse and plays a role in cutting off the current when blown. Fuses of the same type and specification should have the same material, geometric size, resistance value as small and consistent as possible, and the most important thing is to have consistent fusing characteristics. Household fuses are commonly made of lead antimony alloy; The second is the electrode part, which usually has two important components that connect the melt to the circuit. It must have good conductivity and should not generate obvious installation contact resistance; The third part is the support part. The melt of the fuse is generally thin and soft. The function of the support is to fix the melt and make the three parts a rigid whole for easy installation and use. It must have good mechanical strength, insulation, heat resistance, and flame retardancy, and should not produce phenomena such as breakage, deformation, combus
When current flows through a conductor, it will generate heat due to the presence of a certain resistance in the conductor. And the calorific value follows this formula: Q=I2RT; Where Q is the heat generated, 0.24 is a constant, I is the current flowing through the conductor, R is the resistance of the conductor, and T is the time for the current to flow through the conductor; Based on this formula, we can easily see the simple working principle of a fuse. When the material and shape of the fuse are determined, its resistance R is relatively determined (without considering its resistance temperature coefficient). When an electric current flows through it, it generates heat, and as time increases, its heat also increases. The magnitude of current and resistance determines the rate of heat generation, while the construction and installation of a fuse determine the rate of heat dissipation. If the rate of heat generation is less than the rate of heat dissipation, the fuse will not blo
1. Filamentous. Early primitive fuses were directly locked with screws and used for various sizes of old-fashioned switches and sockets. 2. Flaky (bare flake). More convenient to use than traditional filiform. 3. Glass tube shaped. There are several different sizes, commonly found in electronic products. 6.3 x 32 mm (diameter x length) 5 x 20 mm 4. Ceramic tubular. There are several different shapes and sizes to avoid glass bursting. 5. Plastic sheet with metal sheet connector: automotive fuse. 6. Surface mounted component (SMD) type. 7. Cylindrical, plug-in type: directly soldered onto the circuit board, used internally in the product.
MB:+86 13924633629 Ms.vicky
E-mail: waimao@xcfuse.com
Factory :
XC Electronics(Shenzhen)Corp.,LTD
Add: Jinyuan Industrial zone,Heao, Henggang, Shenzhen 518115,China
Shenzhen branch: Shenzhen Xucheng Electronic Commerce co.Ltd
Add: 8-15 Jinyuan Industrial zone,Heao, Henggang, Shenzhen 518115,China
