Fuses are used to protect electrical circuits, also known as fuses, in order to be able to blow in time in the event of a short-circuit fault. The resistance of a fuse is generally higher than the resistance of a wire so that it can protect the circuit. Under normal circumstances, the resistance of the fuse in the range of 0.33Ω-1Ω. Fuse resistance can be large or small, relatively speaking, a fuse with a larger resistance is safer, but if the fuse resistance is too large it will also affect the normal use of electrical appliances. When choosing the resistance of the fuse, according to the size of the wire and the load of household appliances to choose the appropriate resistance size.

First, the fuse resistance value is generally how much?

Fuse as a component to protect the safety of the circuit, generally lower melting point of the metal material, which itself has a certain resistance, so how big is the fuse resistance?
Under normal circumstances, the wire can be passed through the current, its resistance is relatively small, in general circuit calculations are usually not counted, and the resistance of the fuse should be greater than the same length of wire, so that in a short circuit in time to fuse, protect the circuit, the ordinary fuse resistance is generally in the range of 0.33Ω – 1Ω.

Second, is it better to have a large or small fuse resistance?

Fuse resistance has a large and small, different resistance size of the fuse in the actual application of the performance of the process is also different, then the large resistance of the fuse is good or small resistance of the fuse is good?

Generally speaking, the choice of fuse resistance should be selected according to the actual situation, in general, it is recommended to choose a larger resistance of the fuse, the main reason is: according to the principle of fuse blowing, the fuse uses the thermal effect of the current to control the size of the current through the current through the current exceeds the limit value, the fuse will blow; according to the formula Q = I ² RT can be seen, the larger the fuse resistance, in the case of the same current and the same time, the resulting fuse resistance will be lower than that of the current. According to the formula Q=I²RT, the higher the resistance of the fuse, the greater the heat generated under the same current and the same time, the easier it is to blow and the better it is for protecting the circuit. If the resistance of the fuse is small, it will not be able to blow in time even if a large current is passed, which is unsafe.

Of course, the resistance of the fuse should not be too large, or a little over some of the large current will be blown, affecting the normal use of household appliances, it is generally recommended that according to the size of the wire and the load of household appliances to choose the appropriate resistance size of the fuse.