What is the difference between fast-blow and slow-blow fuses?

"Fast blow and slow blow": In fact, it refers to fuses of different usage categories, which are relative to the protected electrical appliances. The fuse used for the protection of general semiconductor devices (SCR, diode, triode, silicon rectifier) is commonly referred to as fast-acting, and its use category belongs to the "aR" category.
In general, slow-blow refers to the "class fuse", which refers to a fuse with a full range of breaking capacity in general use categories. It is generally used for line overload or short-circuit protection. Normal factory fuses include fast-blow and slow-blow. The difference is mainly due to the difference in response time. In fact, the two are different in I2t indicators, and fast-acting fuses are generally used to protect sensitive products from damage.
If a slow-blow fuse is selected by mistake, it may cause damage to the equipment and fail to protect it. Therefore, the basis for selecting a fuse depends on the actual requirements of the protected circuit.