A fuse is a simple circuit protection appliance. Its principle is that when the current flowing through the fuse reaches or exceeds a fixed value for a certain period of time, its own melt melts and cuts off the circuit. The action principle is simple, the installation is convenient, generally not used alone, mainly used to cooperate with other electrical appliances.
Main action characteristics:
First, the current must reach a certain value, which has been done before the fuse leaves the factory and cannot be changed;
Second, after the current reaches a certain value, a certain period of time will pass. This time is also done by the manufacturer and cannot be changed, but there are many types, including delayed action, fast action, super fast action, etc.;
Third, the body is damaged after the action and cannot be reused, it must be replaced;
Whether the fuse is blown can be judged by the fuse indicator, or by the appearance of the melt; commonly used fuses and fuses belong to this category of electrical appliances.