NTC Thermistor Bias – An Essential Guide
Article Summary
Introduction
NTC thermistors are temperature-sensitive resistors that exhibit a decrease in resistance as temperature rises. They find extensive use in various industries for temperature measurement and control applications. Understanding the concept of biasing these thermistors is crucial to ensure accurate and reliable temperature sensing.
Working Principle of NTC Thermistors
NTC thermistors are made from semiconductor materials that exhibit a negative temperature coefficient, meaning their resistance decreases with increasing temperature. This unique characteristic makes them highly suitable for temperature sensing and control purposes. When subjected to temperature changes, the resistance of an NTC thermistor alters, allowing for precise temperature measurements.
The Importance of Biasing
Biasing refers to the process of applying a correct voltage to an NTC thermistor to accurately measure temperature. A biased thermistor operates within a specific temperature range, providing reliable and consistent readings. Without proper biasing, the accuracy of temperature measurements can be compromised, leading to incorrect control actions or inadequate thermal protection.
There are two common ways to bias an NTC thermistor:
- Self-Biasing: In self-biasing, the NTC thermistor is incorporated into a voltage divider circuit. As temperature changes, the resistance of the thermistor affects the output voltage, which is then measured to determine the temperature.
- Externally Biased: In external biasing, an external voltage source is connected in series with the NTC thermistor. The voltage across the thermistor is used to calculate the temperature based on the known characteristics of the device.
Applications
NTC thermistors with biasing are utilized in diverse applications, including:
- Temperature sensors in HVAC systems
- Thermal protection in power supplies
- Temperature compensation in electronic circuits
- Temperature monitoring in industrial processes
In conclusion, understanding the concept of NTC thermistor biasing is essential for accurate temperature measurements and reliable control actions. Proper biasing ensures that the thermistors operate within their specified temperature range, providing precise readings in various applications.
