Self-restoring fuse, also known as Polymer Positive Temperature Coefficient (PPTC) fuse, is a kind of electronic protection element made of high molecular materials with low resistance value under normal working condition, when the circuit produces overcurrent, the resistance value will increase rapidly due to the increase of temperature. Thus limiting the current and playing a protective role. After the circuit is restored to normal, the self-restoring fuse will automatically cool and return to the low resistance state without manual replacement.
The self-restoring fuse has the features of automatic recovery, overcurrent protection, fast response, high reliability and repeated use. It can react to overcurrent in a few milliseconds and automatically recover after troubleshooting, avoiding the trouble of frequent fuse changes in the past.
The main parameters of the self-restoring fuse include holding current (Ihold), triggering current (Itrip), maximum voltage (Vmax), operating time and recovery time. The holding current refers to the maximum working current that the fuse can continue to pass in the 25°C environment, the triggering current is the current threshold at which the fuse begins to work, and the maximum voltage refers to the maximum voltage that the fuse can withstand.
You can check the quality of the self-restoring fuse by checking its appearance, using a multimeter to detect the resistance level, replacing the fuse, or connecting the fuse. If the fuse is burnt or has an odor, or there is no reaction when tested with a multimeter, it indicates that the fuse has been destroyed. It can also be tested by setting a certain current and voltage, inspecting the operating time and recovery characteristics of the fuse.
The model of the self-restoring fuse is composed of letters and numbers, such as ASMD1206-010 indicates the fixed model of the JDT, 1206 represents the volume size, and 010 represents the current of 0.1A. Similarly, A72-050A represents 72V voltage and 050 represents 0.5A current.
Self-restoring fuses are used in automotive electronics, computers, battery packs, chargers, LED lighting and other fields of automotive electronics, can protect USB interface, cigarette lighter circuit, window power supply system and other solar street lights, self-restoring fuses are used as over-current temperature protection to ensure the stable operation of the system.
Self-restoring fuses play a very important role in modern electronic circuits because of their unique self-restoring characteristics. Its protection function and simple test method have made its application in many fields more and more popular. The working principle and parameters are very important when selecting and using self-restoring fuses to ensure the safety and reliability of the circuit.
