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Is the Glass Tube Fuse Vacuum? What Is the Working Principle

Fuses are the usual colloquial name, and their official name is "fuse", and their purpose is similar to that of home fuses. When the load of electrical appliances in the circuit is too large or there is a short circuit in the circuit, resulting in abnormal central current in the circuit and exceeding its rated current, they fuse for protection (line) and electrical equipment are important components to protect the wires, electrical equipment and devices constituting automobile circuits from fire and other accidents.

Working principle of fuse

We all know that when the current flows through the conductor, the conductor will generate heat due to a certain resistance. And the calorific value follows this formula: q = 0.24i2rt; where q is the calorific value, 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 when the current flows through the conductor. According to this formula, it is not difficult for us to see the simple working principle of the fuse ã€‚

When the material and shape of the fuse are determined, its resistance R is relatively determined (if its resistance temperature coefficient is not considered) . when the current flows through it, it will generate heat, and its calorific value will increase with the increase of time. The size of current and resistance determines the rate of heat generation, and the structure of fuse and its installation condition determine the rate of heat dissipation. If the rate of heat generation is less than the rate of heat dissipation, the fuse will not blow. If the rate of heat generation is equal to the rate of heat consumption If the speed of heat generation is greater than the speed of heat dissipation, more and more heat will be generated. Because it has a certain specific heat and mass, the increase of heat is reflected in the increase of temperature. When the temperature rises above the melting point of the fuse, the fuse will blow. This is the origin of the fuse working principle.

Is the glass tube fuse vacuum

The fuse is usually filled with protective gas, not necessarily vacuum.

If there is an air leak, oxygen enters, and the service life of the fuse will be shortened without any obvious phenomenon.