What is thermistor and varistor?

A varistor is essentially an open circuit until its breakdown voltage is exceeded which point it begins its resistance drops steeply. A thermistor is more of a temperature sensitive resistor; it’s not “normally closed”, it’s a resistor.

When would you use a thermistor?

Thermistors are used as temperature sensors. They can be found in every day appliances such as fire alarms, ovens and refrigerators. They are also used in digital thermometers and in many automotive applications to measure temperature.

What can I replace a thermistor with?

Texas Instruments’ LMT87 is a precision analog output temperature sensor that can operate between -58 and 302°F (-50 and 150°C). It is an effective replacement for NTC thermistors because it delivers more accurate and more linear measurements while consuming less power.

How does a varistor work?

Varistors are used to protect a circuit from high voltage surges. When a high voltage surge is applied to a circuit, the outcome is usually catastrophic to the circuit. When a voltage surge exceeding a specified voltage (varistor voltage) is applied, the varistor suppresses the voltage to protect the circuit.

What is the difference between MOV and NTC?

Varistor belongs to metal oxide varistor (MOV), which is a non-linear resistance element with zinc oxide (ZnO) as the main component. NTC thermistor is a temperature-sensitive resistor made of negative temperature coefficient (NTC) and special semiconductor ceramic materials.

Is a thermistor a variable resistor?

The Thermistor is a special type of variable resistive element that changes its physical resistance when exposed to changes in temperature.

What is the difference between a thermocouple and thermistor?

A thermistor is a thermally sensitive resistor that exhibits a continuous, small, incremental change in resistance correlated to temperature variations. Thermocouples reflect proportional changes in temperature through the varying voltage created between two dissimilar metals electrically bonded together.

Can you bypass a thermistor?

Generally speaking, a thermister is a resistor that is sensitive to/affected by ambient heat. When the ambient heat changes, it’s value will change. You can bypass it with a regular resistor, but you have to know the value associated with the thermister.

What advantage does a thermocouple have over the NTC thermistor?

The thermocouple has high accuracy as compared to the thermistor. The thermistor has lead whose resistance reduces their accuracy. The temperature measuring ranges of the thermistor is -50°C to 250°C whereas that of the thermocouple is -200°C to 1250°C.