Overheat protection function of PTC heater element
The PTC heater element is a typical direct-heating step type positive temperature coefficient thermistor. When the temperature increases above the Curie temperature, its resistance value increases stepwise, which can reach 4 to 10 orders of magnitude.
The temperature change can be obtained by the current flowing through the thermistor, or by the external heat input or the superposition of the two. Based on the above characteristics, PTC can be used in circuits for overcurrent protection, overheat protection, temperature measurement, temperature compensation, delayed start, demagnetization, etc. Therefore, it has a wide range of applications in circuits.
PTC electric heater means positive temperature coefficient. The meaning of negative temperature coefficient. The mutant PTC thermistor of the PTC heater is subdivided into two categories. The high-temperature fan is a ceramic PTC thermistor, and the PTC effect can be found after adding semiconducting elements. Incorporating carbon black into polyethylene polymer materials forms the PTC effect.