What Is A Thermistor And How Does It Work

BySANDIP SARKAR

A thermistor is a type of temperature-sensitive resistor that changes its electrical resistance with changes in temperature. It is often used in electronic circuits and devices to monitor and control temperature variations. Thermistors come in two main types: positive temperature coefficient (PTC) thermistors, which have resistance that increases with temperature, and negative temperature coefficient (NTC) thermistors, which have resistance that decreases with temperature. They find applications in temperature measurement, temperature compensation, and temperature control systems.

PTC Thermistor and NTC Thermistor Details below

PTC Thermistor

A Positive Temperature Coefficient (PTC) thermistor is a type of thermistor that exhibits an increase in resistance as its temperature rises. This is in contrast to a Negative Temperature Coefficient (NTC) thermistor, which decreases in resistance as temperature increases. PTC thermistors are commonly used in various applications, including overcurrent protection, self-regulating heaters, temperature sensing, and motor starting circuits.

One of the key features of PTC thermistors is their ability to act as self-resetting circuit protectors. When current flows through them and causes an increase in temperature (due to excessive current or fault conditions), their resistance rises sharply, reducing the current flow and protecting the circuit from damage. As the temperature decreases, the PTC thermistor’s resistance lowers, allowing normal operation to resume.

These characteristics make PTC thermistors useful in situations where automatic temperature-based control or protection is required.

What is ntc Thermistor

A Negative Temperature Coefficient (NTC) thermistor is a type of thermistor that displays a decrease in resistance as its temperature increases. This makes NTC thermistors particularly suitable for temperature sensing and compensation applications. As the temperature rises, the atoms within the thermistor material become more agitated, leading to increased conductivity and a decrease in resistance.

NTC thermistors are commonly used in various industries and applications, such as:

  1. Temperature Sensing: They are used in devices like thermostats, temperature controllers, and weather stations to accurately measure and monitor temperature changes.
  2. Temperature Compensation: NTC thermistors are employed in circuits where temperature changes can affect component performance. By compensating for temperature variations, they help maintain stable circuit operation.
  3. Temperature Monitoring: NTC thermistors are used to provide feedback to microcontrollers or control systems, enabling them to make decisions based on real-time temperature data.
  4. Overcurrent Protection: Similar to PTC thermistors, NTC thermistors can also be used in overcurrent protection circuits. However, they respond to current changes by affecting their resistance, which can limit the current flow.

Overall, NTC thermistors are valuable components for temperature-related applications, providing a cost-effective and accurate way to measure and control temperature changes in various electronic systems.