Time： 2018-10-29 10:06:16
thermal resistor can be divided into PTC Thermistor and NTC Thermistor in accordance with the different temperature coefficient.
PTC thermistor is a kind of typical semiconductor thermal resistor with temperature sensitivity, its resistance will increase by a step with the temperature arising.
PTC thermistors can be divided into below two types in accordance with the different material:
1.Ceramic PTC thermistors.
2.Organic polymer PTC thermistors.
PTC thermistors can also be divided into below types in accordance with the different APPLICATION:
A.Delay start thermistor for lighting and ballast;
B.Intelligent preheat start thermal resistor;
C.Degaussing thermistor for Colour TV,Colour monitor in CRTs .
D.Telecom circuit protection PTC thermistor.
E.Overcurrent and overload protection .
F.Motor protection PTC thermistor.
G.Welding machine overload protection thermal resistor.
H.PTC thermistor for Constant temperature heating;
I.PTC thermistor for temperature sensing.
Normally,Organic polymer PTC thermistors(PPTC) are suitable for the Over-current protection,and Ceramic PTC thermistors are suitable for applications listed as above.
NTC thermistor is a kind of typical semiconductor thermal resistor with temperature sensitivity, its resistance will decrease by a step with the temperature arising.
The main materials of NTC thermistor are metal oxide such as manganese, cobalt, nickel and copper,NTC thermistor is manufactured by ce ceramic processing.
These metal oxide materials used on NTC thermistor are semiconductor,because their conducting way is similar as semiconductor materials such as germanium
and silicon completely.
At low temperature, the number of metal oxide material carriers (electrons and cavity) is less, so the resistance value is higher;With the temperature arising, carriers number increases, so the resistance value reduced accordingly.
NTC thermistors can be divided into below types in accordance with the different APPLICATION:
1.Power type surge suppression NTC thermistor;
2.NTC thermistor for temperature compensation;
3.NTC thermistor for temperature measurement and control.