Fuse resistance refers to the appearance and shape similar to resistance. Limited products are marked with a color ring to distinguish the magnitude of current, so it is also called fuse resistance or PICO fuse. Although fuse resistors and resistors are similar in appearance and shape to resistors, are they the same?
The fuse resistance refers to the partial voltage current limiting and is usually connected in series with the load (electrical product) to prevent the load (electrical product) from burning out or short-circuiting. That is, the function of insurance. If the ordinary fuse is broken, it needs to be replaced and the fuse resistance will not be broken. It is mainly to prevent short circuits (short circuit danger, possible fire, etc.). How much resistance value to use for the insurance resistor depends on the actual problem. If the resistance is too large, a lot of power will be wasted.
The fuse resistance has a function similar to that of a fuse, that is, it can cut off the current when the circuit is overcurrent, and can also function as a fuse, so many people will confuse it. However, the load of a resistor has a certain limit. When the current flowing through the resistor exceeds the limit, the resistor burns out, and the resistor shows an open circuit state. This is different from the fuse protection. The fuse must have three functions at the same time: (1) protection function (2) load-bearing function (3) safety function, while the fuse resistor cannot play a good function in these three aspects.
The protection function covers overload protection and short-circuit protection, that is, when the circuit has an overcurrent that is not allowed until the limit of short-circuit overcurrent, the fuse must be activated within the specified time range to protect the circuit or component However, the technical parameters such as the starting time and action duration of the fuse resistor cannot be as accurate as the fuse, and the overload current protection cannot be guaranteed, and it can only have a little effect on the short-circuit current.
The load-bearing function of the fuse is guaranteed by the melting heat value, so that the fuse can bear the pulse impact of a certain energy with the necessary number of switching times. It must be calculated and evaluated when selecting it. However, the fuse resistance itself does not have similar technical indicators and is used less. It will be interrupted by pulses, and there is no protection function if it is used too much.
The safety function, the fuse is guaranteed by the rated voltage, breaking capacity and other indicators, especially the authoritative third-party safety certification to ensure that, but the insurance resistor itself is not a safety element, and does not require safety certification, its safety can be It is conceivable that its own protection function is insufficient, and it is difficult to ensure that there will be no unsafe phenomena that endanger the surroundings during the burn-out process.