Resettable Fuse PPTC working principle:
- Normal working state: Under normal working conditions, the resistance of PPTC remains in a low resistance state, allowing current to pass without affecting the normal operation of the circuit.
- Overcurrent condition: When the current exceeds the rated value of PPTC, the flowing current generates heat. If this heat cannot be effectively dissipated to the environment, the temperature of PPTC will rise.
- Action process: When the temperature of PPTC reaches its action point (i.e. a specific critical temperature), its resistance will increase rapidly and enter a high resistance state. This process usually occurs within a few milliseconds, thereby limiting the current flowing.
- Protection effect: As the resistance increases, the current flowing through it will drop sharply, thus preventing further overcurrent conditions and protecting the circuit and connected devices from damage.
- Resettable characteristics: Once the overcurrent condition is relieved and the applied voltage disappears, the temperature of the PPTC will drop and the resistance will return to the initial value, which allows the PPTC to be reused without replacement.
What are the typical application scenarios of the Resettable Fuse PPTC?
Due to its unique characteristics, it has a wide range of applications in many fields. The following are some typical application scenarios:
- Battery protection: PPTC devices are often used to protect lithium-ion batteries and lithium polymer batteries from overcharging, over-discharging and short circuits, ensuring the safety and service life of the battery.
- Electronic equipment protection: PPTC devices can be used to protect portable electronic devices such as laptops, mobile phones, and tablets from damage caused by short circuits or overloads.
- Motor protection: PPTC devices can be used to protect motors and motor drive circuits from overcurrents caused by stalling or overloads, extending the service life of motors.
- Communication equipment protection: PPTC devices can be used to protect communication equipment such as routers, switches, base stations, etc. to prevent overcurrent damage caused by lightning strikes or electrostatic discharge.
- Industrial equipment protection: PPTC devices can be used to protect industrial automation equipment, PLC controllers, etc. to prevent overcurrent damage caused by short circuits or overloads.
- Household appliance protection: PPTC devices can be used to protect household appliances such as electric fans, electric irons, induction cookers, etc. to prevent overcurrent damage caused by short circuits or overloads.