PTC Thermistor Working Principle

• 

PTC thermistor (Positive Temperature Coefficient Thermistor) is a temperature-sensitive semiconductor resistor. Once it exceeds a certain temperature (Curie temperature), its resistance value increases almost stepwise with the increase of temperature. The temperature change of the positive temperature coefficient thermistor can be obtained by the current flowing through the PTC thermistor, or by the external heat input or the combination of the two.

Ceramic materials are usually used as excellent insulators with high resistance. Ceramic PTC is made of barium titanate and doped with other polycrystalline ceramic materials, which has low resistance and semiconductivity. It is achieved by purposefully doping a material with higher chemical valence as the lattice element of the crystal: a part of barium ions or titanate ions in the crystal lattice is replaced by higher valence ions. Therefore, a certain number of free electrons are obtained.

Then, let's look at the reason for PTC thermistoreffect, in other words, the reason for the step increase in resistance value. The material structure is composed of many small crystallites, and the potential is formed on the grain boundary, which prevents the electrons from crossing the boundary into the adjacent area, thus resulting in high resistance. This effect is offset at low temperatures: the high dielectric constant and spontaneous polarization at the grain boundary hinder the formation of barriers and allow electrons to flow freely at low temperatures. At high temperatures, this effect greatly reduces the dielectric constant and polarization, leading to a substantial increase in the barrier and resistance, showing a strong PTC effect.

PTC is a kind of semiconductor heating ceramic. When the external temperature decreases, the resistance value of PTC decreases, and the calorific value increases correspondingly. PTC thermistor working principleis as follows: once it exceeds a certain temperature (Curie temperature), the resistance increases of positive temperature coefficient resistor with the increase of temperature almost in a step-by-step manner. The temperature change of PTC thermistor types body can be obtained by the current flowing through it, or by the external input heat or the combination of the two. Ceramic materials are usually used as excellent insulators with high resistance, PTC ceramics are based on barium titanate and doped with other polycrystalline ceramic materials, which have low resistance and semiconductivity. It is achieved by purposely doping a kind of material with higher chemical value as the lattice element of the crystal: in the lattice, part of barium ions or titanate ions are replaced by higher valence ions. Therefore, a certain number of free electrons are obtained.

As one of industrial sensor suppliers, we will do our best to meet all the needs of customers.

Другие товары поставщика

	SMD Thermistor	Also called surface mount thermistor. Details Material: Semiconductor ceramics Applicable temperature range：-40~120℃ Output signal: analo...
	Details Material: memory metal Control accuracy: ±5℃ Advantages 1. Temperature control and temperature detection of household appliances such as induction cooker, electric pressure cooker, rice cook	TPS24 type Microwave temperature sensoris a high level temperature sensor, very stable performance with very short response time, when you need to ...
	BBQ Meat Probe Temperature Sensor	Details Material: 0.8mm single-ended glass-sealed thermistor/SUS304 stainless steel probe/308℃ dual-channel audio steel network cable Applicable t...
	Printer & Copier Temperature Sensor	Details Material: semiconductor ceramic resistor chip / high-efficiency conductive Dumet wire/glass Applicable temperature range: -45~500℃ O...
	Dust Sensor	D7 is a kind of digital and universal particle concentration sensor. PM1.0 PM2.5 PM10 Laser Dust Particle Sensor Module The air quality module use...

Похожие товары

	China manufacturer đầu dò nhiệt độ Wrnk2-131 for power generation	Продавец: DONGFANG YOYIK (DEYANG) ENGNIEERING CO; LTD	"China manufacturer đầu dò nhiệt độ Wrnk2-131 for power generationYOYIK is a large number ...
	Sensor TEP11X321809 for power station	Продавец: DONGFANG YOYIK (DEYANG) ENGNIEERING CO; LTD	"China factory Sensor đo nhiệt độ bồn dầu thủy lực TEP11X321809 for power station Yoyik is spec...
	High Frequency Modules PL-M20 (110V) for thermal power	Продавец: DONGFANG YOYIK (DEYANG) ENGNIEERING CO; LTD	"Made in China High Frequency Modules PL-M20 (110V) for thermal power plant The use of advanced t...
	China supplier Dissolved Oxygen Secondary Display Instrument UDA2182-DB1-NN2-NN-N-0000-EE	Продавец: DONGFANG YOYIK (DEYANG) ENGNIEERING CO; LTD	China supplier Dissolved Oxygen Secondary Display Instrument UDA2182-DB1-NN2-NN-N-0000-EE power p...
	China manufacturer Thermocouple WREKD2-04A for power generation	Продавец: DONGFANG YOYIK (DEYANG) ENGNIEERING CO; LTD	"China manufacturer Thermocouple WREKD2-04A for power generationis an exclusive product for power...