What Are Semiconductor Fuses?
A fuse is also called a current fuse, and the IEC127 standard defines it as a "fuse-link." It is mainly used for overload protection. If the fuse is correctly placed in the circuit, the fuse will automatically cut off the current when the current abnormally rises to a certain height and heat, which protects the safe operation of the circuit. [1]
- When the circuit is faulty or abnormal, the current is constantly increasing, and the
- When a current between the conventional non-fusing current and the rated breaking capacity (current) specified by the relevant standard is applied to the fuse, the fuse should be able to operate satisfactorily without endangering the surrounding environment. The expected fault current of the circuit in which the fuse is placed must be less than the rated breaking capacity current specified in the standard; otherwise, when the fault occurs, the fuse will continue to flash, ignite, burn the fuse, melt together with the contacts, and the fuse mark cannot be identified. phenomenon. Of course, the breaking capacity of inferior fuses does not meet the requirements of the standard, and the above-mentioned hazards will also occur when used. [2]
- 1. The normal operating current is operated at 25 ° C, and the current rating of the fuse is usually reduced by 25% to avoid harmful melting. Most traditional fuses use a material with a lower melting temperature. Therefore, this fuse is more sensitive to changes in ambient temperature. For example, a fuse with a current rating of 10A is generally not recommended to operate at a current greater than 7.5A at an ambient temperature of 25 ° C.
- Resettable fuse
- Resettable fuse or overcurrent protection sheet [3] .
- Resettable fuse
- Temperature fuse
- The temperature insurance film will deform when the temperature exceeds a certain safe temperature, leading to power failure, and the temperature can be restored.
- Thermal fuse
- Thermal cutoffs are common in today's electric heating devices and will blow when the temperature exceeds a certain safe temperature.
- Devices with thermal fuses include: electric cookers, electric heaters, coffee makers, hair dryers, etc.
- Although the specification of the thermal fuse also has an allowable current, it should be noted that the thermal fuse does not have the same current protection function as the current fuse and should not be confused.