Fuse: also known as fuse block, when the circuit fault or abnormal, with the current constantly increased, and the increased current may damage some important components in the circuit, but also may burn down the circuit or even cause a fire, its own fuse cut off the current, protect the safe operation of the circuit.

“FU” is commonly used in general circuits

Now the circuit density is the highest, patch recovery fuse (PTC) due to overcurrent caused by the temperature rise, expansion and transition to a high resistance state, and on and off, when the fault recovery, back to normal operation, and with overcurrent overheat protection, automatic recovery of the dual function.It is more and more used in low voltage power supply protection circuit.

Self-recovery fuse is a kind of overcurrent electronic protection element, which is made of high polymer organic polymer under the condition of high pressure, high temperature and vulcanization reaction, mixed with conductive particle material, and then processed by special process.

Fuses are safety devices and use in that country requires safety certification or recognized general certification in the country of use.

For example, the maximum current 7A is used in the power frequency power grid, where the power supply fluctuates greatly.

IEC fuse actual use of maximum current /0.9

UL fuse actual use of maximum current /0.75

The margin of domestic fuses can be taken according to UL fuses, and the maximum instantaneous inrush current that may occur in the power grid should be less than fuse I2t

Check the fuse data manual and choose 10A/250V, slow fuse.