How do thermistors regulate temperature in a circuit?

Thermistors regulate temperature in a circuit by changing their resistance in response to temperature changes.

A thermistor is a type of resistor whose resistance varies significantly with temperature. This unique characteristic makes them ideal for use in temperature sensing circuits. They are made from semiconductor materials, which means their resistance decreases as the temperature increases, or vice versa. This property is known as negative temperature coefficient (NTC) or positive temperature coefficient (PTC) respectively.

In a circuit, a thermistor can be used to regulate temperature by being part of a feedback loop. When the temperature changes, the resistance of the thermistor changes as well. This change in resistance can be used to control the current flowing through the circuit. For example, if the temperature increases, the resistance of an NTC thermistor decreases, allowing more current to flow through the circuit. This increased current can then be used to activate a cooling device, such as a fan, to bring the temperature back down.

On the other hand, a PTC thermistor works in the opposite way. If the temperature increases, the resistance of a PTC thermistor increases, reducing the current flowing through the circuit. This reduced current can be used to deactivate a heating device, preventing the temperature from rising further.

In addition to temperature regulation, thermistors are also used in a variety of other applications. For example, they can be used in digital thermometers to measure temperature, in automotive applications to monitor engine temperature, and in home appliances like ovens and refrigerators to maintain a consistent temperature.

In summary, thermistors play a crucial role in temperature regulation in a circuit. By changing their resistance in response to temperature changes, they can control the current flowing through the circuit, thereby controlling the activation and deactivation of heating or cooling devices.