termisztorokra

A thermistor is a type of resistor whose resistance is strongly dependent on temperature, more so than in standard resistors. The word thermistor is a portmanteau of "thermal" and "resistor". Thermistors are widely used as temperature sensors. The two types of thermistors are Negative Temperature Coefficient (NTC) thermistors and Positive Temperature Coefficient (PTC) thermistors.

In an NTC thermistor, the resistance decreases as temperature increases. This behavior is due to the semiconductor material used in their construction. As temperature rises, more charge carriers are freed, increasing conductivity and thus decreasing resistance. NTC thermistors are commonly used in temperature sensing, inrush current limiting, and battery pack protection.

In a PTC thermistor, the resistance increases as temperature increases. This typically occurs in two distinct phases. At lower temperatures, the resistance is relatively low. As the temperature rises past a certain point, the resistance increases sharply, often by several orders of magnitude. This effect is often used for overcurrent protection and self-regulating heating. PTC thermistors are made from polycrystalline ceramics or polymers.

Thermistors offer high sensitivity to small temperature changes, making them suitable for precise temperature measurements. However, they can also be non-linear, requiring more complex circuitry for linearization if needed. Their applications span across various industries, including automotive, medical devices, consumer electronics, and industrial control systems.