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

	Enameled Wire Thermistor	Also called adjustable wire wound resistor Specification: TPS13 Details Material: Semiconductor ceramics/epoxy/Enameled wire Applicable temperatu...
	PM1.0 PM2.5 PM10 Laser Particle Dust Sensor Digital Module	D7 is a kind of digital and universal particle concentration sensor, which can be used to obtain the number of suspended particles in the air,i.e.t...
	Temperature And Humidity Sensor/Detector/Probe	Specification: DHT11-AC Details Material: Resistive humidity sensing element and an NTC temperature measuring element are connected to a high-perf...
	Temperature Sensor	Different Pellet Grill Inside Temperature Sensor TPS200813-31 TPS24 type Microwave temperature sensorand temperature transduceris a high level...
	Disposable Medical Body Probe	Specification: TPS180913-21 Details Material: the medical temperature probe is made of a high-precision medical chip/silicone cable/mono audio ...

Похожие товары

	T60404-N4646-X400	Продавец: 双为（香港）科技有限公司	Датчик тока для монтажа на плату Датчик тока 25A 3 контакта +/-15В Атрибуты продукта Значение ат...
	Hangzhi CAFR-A-NP Series PCB Current sensor	Продавец: Shenzhen Hangzhi Precision Electronics Co., Ltd	Серия CAFR-A-NP — это датчик тока, разработанный Hangzhi, который можно припаять к печатной...
	Hangzhi CIT High Precision Split Core current transducer	Продавец: Shenzhen Hangzhi Precision Electronics Co., Ltd	Высокоточный преобразователь тока с разъемным сердечником серии CIT разработан компанией Hangzhi ...
	BMS300 Automotive Current Sensor Transducer	Продавец: Shenzhen Hangzhi Precision Electronics Co., Ltd	BMS300 феррозондовый преобразователь состоит из возбуждающего магнитного кольца и схемы управлени...
	AIT6000-SG High-Precision Current Sensor Transducer, Accuracy 50ppm	Продавец: Shenzhen Hangzhi Precision Electronics Co., Ltd	AIT6000-SG имеет высокий коэффициент усиления и точность измерения во всем диапазоне полосы пропу...