The working principle of PPTC resettable fuse is the dynamic balance of energy. Due to the PPTC relationship, the current flowing through the PPTC components generates heat, and the generated heat is completely or partially discharged into the environment, and the un-emitted heat will increase the PPTC components. temperature.
The temperature during normal operation is low, and the heat generated and the heat generated are balanced. The PPTC element is in a low-resistance state, the PPTC does not work, the current flowing through the PPTC element increases or the ambient temperature increases, but if the balance of heat generated and heat dissipation is reached, the PPTC still does not operate. When the current or ambient temperature increases, PPTC will reach a higher temperature. If the current or ambient temperature continues to increase, the heat generated will be greater than the heat dissipation, causing the temperature of the PPTC component to rise rapidly. At this stage, a small temperature change will cause a large increase in resistance, and the PPTC element is in a high-resistance protection state. When the fault is eliminated, the PPTC component quickly cools and returns to its original low resistance state, which in turn can be re-worked like a new PPTC component.
The advantages of PPTC resettable fuse:
1 With initial resistance value
2 Always in high resistance state until the fault is eliminated
3 Due to the small size, PPTC resettable fuse moves faster
4 PPTC resettable fuses can also provide overcurrent protection (multiple times)
5 The life of PPTC self-resetting fuse can be regarded as unlimited.
Application fields of PPTC resettable fuses:
PPTC self-recovery fuses for computers and peripherals mobile phones battery packs telecommunications and network equipment transformers industrial control equipment overcurrent or overtemperature protection in automobiles and other electronic products