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.
Send product request
Other supplier products
 |
Thermistor | Types of Thermistor FunctionThere are two types of thermistors: ntc and ptc thermistor. Although these two are made of different materials, both ca... |
 |
NTC Thermistor | NTC Thermistor Types Glass Bead Thermistor, Single-ended Glass Encapsulate Thermistor Specification/model format: MTG2-1/2/3/4 Glass Bead Thermi... |
 |
Infrared Carbon Dioxide CO2 Gas Sensor Module Detection 0-5000ppm | QC102 NDIR infrared carbon dioxide sensoris a common type, small size sensor, using non-dispersive infrared (NDIR) principle to detect the existenc... |
 |
Coffee Maker Temperature Sensor | Coffee Maker Temperature Sensor Specification: TPS191220-21 Details Material: Thermistor/PVC Wire Applicable temperature range: -30~120℃ ... |
 |
Sensors Used In Home Appliances | Home Appliances Sensors Introduction TOPOS sensors solutions to meet the daily demands of sensors used in home appliances. By leveraging our es... |
Same products
 |
China manufacturer Pressure Gauge HS75668 for power generation | Seller: DONGFANG YOYIK (DEYANG) ENGNIEERING CO; LTD | "China manufacturer Pressure Gauge HS75668 for power generation It is YOYIK special sale. Deyang ... |
 |
"China factory Vacuum Switch HS70595 for power station | Seller: DONGFANG YOYIK (DEYANG) ENGNIEERING CO; LTD | "China factory Vacuum Switch HS70595 for power station Our company mainly serves thermal power pl... |
 |
China made TSI Preamplifier CON021/916-240 for power plant | Seller: DONGFANG YOYIK (DEYANG) ENGNIEERING CO; LTD | China made TSI Preamplifier CON021/916-240 for power plant Dongfang Yoyik has advanced technology... |
 |
China manufacturer Preamplifier for power generation | Seller: DONGFANG YOYIK (DEYANG) ENGNIEERING CO; LTD | "China manufacturer Preamplifier for power generationIs to use the generator sets of professiona... |
 |
China Yoyik Upper bearing positioning sleeve DLD320-20X2 for turbine generator | Seller: DONGFANG YOYIK (DEYANG) ENGNIEERING CO; LTD | "China Yoyik Upper bearing positioning sleeve DLD320-20X2 for turbine generatorSold by YOYIK. Dey... |
