ニュース

    PTC thermistor is a component whose resistance value rises rapidly when the temperature reaches a certain value. They are typically made of doped ceramic materials and are used in a wide variety of applications requiring temperature protection and current limiting.

  Features

- Self-recovery function: When the current is too large or the temperature is too high, the PTC thermistor will heat up rapidly and the resistance value will increase significantly, limiting the current flow and protecting the circuit from damage. When the fault is eliminated, its temperature decreases, the resistance returns to a low value, and the circuit resumes normal operation.

- High reliability: PTC thermistor can perform protection functions repeatedly without the need for replacement or manual reset.

- Fast response: PTC thermistor can respond quickly to temperature changes, providing instant protection.

- Long life: Because it has no mechanical moving parts, PTC thermistors have a relatively long service life and are able to maintain stable performance under multiple overcurrent or overheating conditions.

    The working principle of PTC thermistor is based on its positive temperature coefficient characteristic. When the current is too large or the ambient temperature is too high, the temperature of the PTC thermistor rises rapidly, causing the resistance value to increase sharply, thereby limiting the amount of current passing and protecting the circuit from damage. Once the temperature drops to a certain range, the resistance value will return to its original state and the circuit will work normally again.

    PTC thermistors are widely used in over current protection in circuits. They can automatically limit the current flow when the current is too large to prevent components in the circuit from being damaged due to over current. Common applications include power adapters, chargers, motor control circuits, etc.

    In some temperature control applications, PTC thermistors are used as temperature sensors. When the temperature rises to the set value, the resistance value increases, and the signal triggers the circuit control system to adjust, such as heater temperature control, fan start, etc.

    PTC thermistors are used as overheating protection components in household appliances and industrial equipment. For example, in transformers, lighting equipment, motors and batteries, when the temperature of the equipment exceeds the safe range, the PTC thermistor will quickly heat up, increase the resistance value, cut off the current or limit the current to prevent the equipment from overheating and damage.

    In communication equipment, PTC thermistors are often used for overvoltage protection and overcurrent protection to ensure that equipment can operate safely under unstable voltage or current conditions. They are widely used in telephone lines, modems, Ethernet interfaces, etc.

    In the field of automotive electronics, PTC thermistors are used in battery management systems, windshield defrosting systems and car lighting circuits. They can provide protection at critical moments, extend the service life of equipment, and ensure the stability and safety of vehicle electronic systems.

    When selecting a PTC thermistor, you need to consider the following factors:

- Rated current: Ensure that the PTC thermistor can pass the rated current under normal operating conditions without triggering overcurrent protection.

- Resistor Value: Choose an appropriate initial resistor value to ensure proper circuit operation.

- Response time: Choose the appropriate response speed according to application requirements.

- Operating temperature range: Ensure that the PTC thermistor can operate normally within the expected temperature range.

    PTC thermistors have become indispensable protection components in various electronic circuits due to their self-recovery function, high reliability and versatility. By accurately selecting and applying PTC thermistors, the safety and durability of the circuit can be greatly improved, and the stable operation of the equipment can be maintained in various complex environments.