Views: 0 Author: Site Editor Publish Time: 2019-06-12 Origin: Site
There are twelve kinds of parameters of the thermistor. In order to understand the main parameters of the thermistor more quickly, this article will share with you the main parameters. Let's take a look at it!
The main parameters of the power thermistor are: steady state current, R25 resistance value, dissipation coefficient, B value and so on.
1. Steady-state current: refers to the large continuous current value that the thermistor is allowed to apply to the thermistor at an ambient temperature of 25 °C. This value must be higher than the thermistor operating current value in the actual circuit.
2, R25 resistance: refers to the design resistance of the thermistor, that is, the zero power resistance value at 25 ° C (usually the resistance accuracy is about 20 percent). This value can indicate the current limiting capability of the thermistor at the moment of start-up.
3. B value: is the thermal coefficient, which is the ratio of the difference between the natural logarithm of the zero power resistance value and the reciprocal of the two temperatures at two temperatures (see the thermistor temperature characteristic formula). The larger the B value, the smaller the residual resistance and the smaller the operating temperature rise.
4. Dissipation coefficient: refers to the ratio of the power dissipation of the device itself to the corresponding temperature change at the specified ambient temperature.
Thermal time constant: refers to the time value of 63.2% of the time required for the surface temperature of the thermistor to start and end when the temperature is abrupt under zero power conditions. The larger the product of the thermal time constant and the dissipation coefficient, the larger the heat capacity of the thermistor and the stronger the ability to stop the inrush current
