Optional elements of thermistor

Thermistor is typically characterized by temperature sensitivity and different resistance values at different temperatures. Positive Temperature Coefficient (PTC) has a higher resistance value at higher temperatures. Negative Temperature Coefficient (NTC) has a lower resistance value at higher temperatures, and they belong to the same semiconductor device. What are the options for thermistor?

1) NTC's large operating current > the operating current of the actual power circuit.

2) The nominal resistance value of the power type thermistor R≥1.414*E/Im type E is the line voltage Im is the surge current for the conversion power supply, the inverter power supply, the switching power supply, the UPS power supply, Im=100 times the working current for the filament , the heater and other circuits Im = 30 times the working current.

3) The larger the B value, the smaller the residual resistance and the smaller the temperature rise during operation.

4) Generally speaking, the larger the product of the time constant and the dissipation coefficient, the greater the heat capacity of the resistor and the stronger the ability of the resistor to suppress the inrush current.

In addition to the optional elements mentioned above, the use environment of the thermistor is also very important, and the environment also determines the service lifetime of the resistor.