In modern electrical equipment and electronic products, fuses, as important protection components, play a key role in ensuring the safe operation of the system. According to different protection objects and working principles, fuses are mainly divided into two categories: thermal fuses and current fuses. Understanding the difference between thermal fuses and current fuses is of great significance for rational selection and effective maintenance of equipment safety. This article will analyze the differences between the two in detail from many aspects to help readers fully master relevant knowledge.
1. Definition and working principleThermal fuse, also known as thermal fuse, is a protection component that is triggered by temperature. When the ambient temperature or the temperature of the component itself reaches the set value, the sensitive material in the fuse will melt, thereby cutting off the circuit and preventing the equipment from overheating and causing malfunctions or fires.Current fuse is a protection device that uses current as the triggering condition. When the current in the circuit exceeds the rated value, the metal wire inside the fuse melts due to overheating, cutting off the circuit and preventing circuit components from being damaged due to overload or short circuit.2. Different trigger conditionsThe triggering basis of the thermal fuse is temperature. It is suitable to prevent equipment from being damaged or causing safety accidents due to excessive temperature. It is common in motors, electric heating appliances and other occasions that require temperature monitoring.Current fuses are triggered based on current flow and are mainly used to protect circuits from overloads and short circuits. They are widely used in various electrical equipment and electronic products.3. Differences in structure and materialsThermal fuses are usually made of a special heat-sensitive alloy material that physically changes when it reaches a specific temperature, causing the fuse to open.Current fuses are generally made of fusible metal wire. The diameter and material of the wire determine its current rating and fusing characteristics.4. Differences in application fieldsThermal fuses are mostly used in motors, transformers, electric heating equipment, chargers and other occasions where overheating needs to be prevented, especially in equipment where temperature monitoring is extremely important.Current fuses are widely used in household appliances, electronic equipment, automobile circuits, etc. to prevent damage caused by abnormal current.5. Response speed and protection accuracyA thermal fuse has a relatively slow response because it relies on temperature increases and is suitable for protecting equipment from long-term overheating damage.The current fuse has a fast response speed and can quickly cut off the circuit to prevent damage caused by instantaneous overcurrent, and the protection effect is more direct and rapid.6. Reset and replacement methodsThermal fuses are generally for one-time use. They need to be replaced with new ones after they are blown, and attention must be paid to matching the temperature level when replacing them.Current fuses are mostly disposable, but some specially designed current fuses (such as resettable fuses) can automatically reset after the fault is resolved.7. Differences in logos and specificationsThe specifications of thermal fuses usually take the fusing temperature as the main indicator, such as 72℃, 90℃, etc.The specifications of the current fuse are expressed in terms of rated current and rated voltage, such as 5A/250V.As important components of electrical protection, thermal fuses and current fuses can cut off circuits to prevent equipment damage and safety accidents, but there are significant differences in their triggering conditions, structural materials, application areas and protection characteristics. Thermal fuses focus on temperature protection and are suitable for preventing problems caused by overheating; while current fuses focus on current protection and prevent overloads and short circuits. Reasonable selection of the two fuses, combined with the actual needs of the equipment, can effectively improve the safety and reliability of the equipment. Understanding the differences can help engineers and technicians make more scientific decisions during the design and maintenance process.
