Table of Contents
What is thermistor PTC and NTC?
There are two separate types of thermistors available on the market today: NTC and PTC. PTC stands for positive temperature coefficient and NTC is negative temperature coefficient. An NTC’s resistance will decrease with temperature; where as, the resistance from PTCs will increase.
What is the difference between PTC and NTC thermistor?
They are available with either a negative temperature coefficient, (NTC) of resistance or a positive temperature coefficient (PTC) of resistance. The difference being that NTC thermistors reduce their resistance as the temperature increases, while PTC thermistors increase their resistance as the temperature increases.
What happens when a thermistor fails?
When a thermistor is failing, it’ll display incorrect temperatures, or you’ll see impossible temperature fluctuations. For example, you may initially get a reading of 210 degrees only to see the temperature drop to 189 degrees and jump back up again.
What is a PTC thermistor?
What are PTC Thermistors? PTC stands for “Positive Temperature Coefficient”. PTC thermistors are resistors with a positive temperature coefficient, which means that the resistance increases with increasing temperature.
What is Curie temperature of PTC thermistor?
The Curie temperature is most of the time defined as the temperature at which the resistance is twice the value of the minimum resistance. The minimum resistance of a PTC thermistor is the lowest resistance that can be measured on a switched type PTC thermistor, as seen on the R-T curve.
How does a thermistor work?
When power is first applied, the thermistor is in a cold state (room temperature). The lamp voltage is below the ignition voltage and the current flowing through the circuit heats up the electrodes and the PTC at the same time.
What is rated PTC resistance and what does it mean?
It is the point on the curve after which the temperature coefficient turns positive. The rated PTC resistance is normally defined as the resistance at 25 °C. It serves to classify the thermistors according to their resistance value.