1, determine the parameters of the circuit:
A maximum operating ambient temperature B standard operating current C maximum working voltage (Umax) d maximum fault current (Imax)
2, the principle of self recovery fuse
Self recovery fuse is made by special process of high tech polymer resin and nano conductive grains.
With the resin based conductive path forming a chain link, fuse the normal work; when the circuit short-circuit or overload, large current flows through the fuse set temperature, when the temperature reaches Curie, its density decreases rapidly, phase transition increases, a conductive link inside the avalanche state change or break, a fuse step - moved to the high impedance state current is quickly pinch off, thus to circuit fast, accurate limit and protect the small current of the fuse has been in a state of protection, when power failure and fault exclusion, the set temperature decreased, the density of States increases, phase recovery, nano crystal reduction into a chain of conductive path, since the recovery fuse returned to normal, without manual change. 3, the maximum electrical rating of the selected components and the maximum operating voltage of the circuit and the fault current for comparison
Use the electrical characteristics table to verify the maximum operating voltage and fault current of the device you selected in the second step. Maximum operating voltage and maximum fault current of the device. Make sure that Umax and Imax are greater than or equal to the maximum operating voltage and maximum fault current of the circuit.
4, according to the maximum operating temperature of the circuit and the circuit, the control self recovery fuse temperature reduction rate to choose the appropriate product specifications to maintain the current
5, verify the working temperature of the environment
Ensure that the minimum and maximum ambient temperature of the application is within the operating temperature range of the self recovery fuse element. Most of the operating temperature ranges from -40 to 85.
6 control specifications provided by the data, confirm the specifications of the thermistor size to meet the requirements.