Details:

PTC-resistor temperature sensors (also called PTC-resistors or thermistors) are temperatur dependent semiconductor resistors whose main function is to alter their electrical resistance drastically when their body temperature reaches the nominal trip temperature NAT (TNF).PTC-resistors are used principally to protect windings in electromotors or transformers against excess temperature. They also find application in machines, tooling machines especially machine bearings and controlling the temperature of power semiconductors.PTC-resistor temperature sensors are particularly suited to this purpose due to their precise response range combined with small dimensions and minimal thermal inertia at low cost. 

Technichal Data

Max. operational voltage.......25 V DC Measuring voltage at 
NAT+15K
-20...NAT+5K.......
? 7,5 V DC
? 2,5 V DC Nominal response temperature NAT (TNF).......60...180°C Tolerance NAT.......± 5 K Nominal resistance R at
-20...NAT-20K
VPTC ? 2,5 V.......? 250 ? Rated ambient temperature range.......-20°C...NAT+20°C Thermal response-time ta.......? 5 s Storage temperature.......-25°C...+65°C Rated insulation voltage Ueff.......690 V Test voltage Ueff.......2500 V AC