What Are The Fuctions Of Thermal Fuse

What Are The Fuctions Of Thermal Fuse

Function one:

When the circuit fails or is abnormal, the temperature of the current will continue to rise, and the increased current may damage some important components or parts of the circuit, and even if it is strictly important, it may cause the circuit to be burned or even cause a fire. . If a fuse is installed in the circuit, then the fuse will cut off the current through its own fuse when the current abnormally rises to a certain height and at a certain time, so as to protect the safe operation of the circuit.

Function two:

The fuse is also called overcurrent protector, also called ten thousand times fuse, also called self-resetting overcurrent protector or polymer self-recovery fuse. In normal operation, the fuse is low resistance. When it encounters high voltage transmission In the event of lightning or lightning, the device will be triggered to generate a large current. The large current will cause the self-recovery fuse to change to a high resistance, thereby limiting the high current that passes. When the power is cut off or the lightning passes, the fuse will automatically return to a low resistance. , So that the circuit returns to the normal state, so as to achieve the purpose of protecting the circuit.

When an abnormal current is generated in the circuit, the current collection will cause the heat generated by the fuse to be greater than the heat dissipated, resulting in a sudden increase in the temperature of the fuse, resulting in a substantial increase in resistivity, which will also limit the flow of current at this time. The heat dissipation capacity directly affects the operating time of the fuse. In comparison, the time to heat up to the high resistance region becomes longer. The fuse will also respond slowly.

Function three:

Therefore, the characteristic of the recoverable fuse is that it can eliminate the abnormal current after the current is cut off. It can also reduce the temperature of the fuse quickly and restore it to a low-resistance conductor. At this time, if the heat dissipation capacity is too strong, it will cause the fuse to cool down faster, and the recovery time will be shortened.

Function four:

However, if there is a contradiction between the action time and the recovery time, it needs to weigh and consider various factors to deal with it, which can avoid some failures and other accidents. Therefore, I think the first thing to consider when choosing the packaging material of the fuse is the matching of the thermal expansion coefficient, and the other is the lower heat capacity and appropriate thermal conductivity. At the same time, epoxy resin can also be used as the packaging material.